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Spondylodiscitis management

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Spondylodiscitis management

J.Sales-Llopis

Neurosurgery Department, General University Hospital Alicante, Spain

Latest PubMED Articles

Spondylodiscitis, requires a multidisciplinary approach for effective management. The goal is to eradicate the infection, prevent or treat complications (e.g., deformity, neurological deficits), and restore spinal stability and function.

see Spondylodiscitis treatment

Key Components of Management

1. Diagnosis

Accurate and early diagnosis is critical for effective treatment.

  • Clinical Presentation:
    • Symptoms: Back pain (most common), fever, localized tenderness, and occasionally neurological deficits.
    • Risk factors: Immunosuppression, recent surgery, infections, or intravenous drug use.
  • Laboratory Investigations:
    • Elevated inflammatory markers: C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and leukocytosis.
    • Blood cultures: Identify causative organisms (positive in ~50-70% of cases).
  • Imaging:
    • MRI (gold standard): High sensitivity and specificity, detects soft tissue and bone involvement.
    • CT-guided biopsy: Essential for microbiological diagnosis when blood cultures are negative.

2. Medical Management

  • Antibiotics:
    • Empiric therapy: Cover gram-positive (e.g., *Staphylococcus aureus*), gram-negative, and anaerobic organisms.
    • Targeted therapy: Adjusted based on blood or biopsy cultures.
    • Duration: 6–12 weeks (longer for complicated cases or immunocompromised patients).
  • Supportive Measures:
    • Pain management with NSAIDs or opioids.
    • Immobilization: Bracing may reduce pain and prevent deformity in acute phases.

3. Surgical Management

Surgery is indicated in specific scenarios:

  • Indications:
    • Neurological deficits (e.g., weakness, bowel/bladder dysfunction).
    • Spinal instability or deformity (e.g., kyphosis >20°).
    • Abscess formation (e.g., epidural or paravertebral abscesses).
    • Failure of medical therapy (e.g., persistent infection despite antibiotics).
  • Techniques:
    • Minimally invasive surgery (MIS): Drainage of abscesses, debridement, stabilization.
    • Open surgery: Extensive debridement and reconstruction for severe instability or deformity.

4. Rehabilitation and Follow-Up

  • Physical Therapy: Promotes recovery of function and prevents deconditioning.
  • Regular Monitoring:
    • Clinical symptoms and inflammatory markers to assess response.
    • Follow-up imaging (MRI or CT) in unresolved cases or when complications are suspected.

Complications to Monitor

  • Neurological deficits.
  • Chronic pain or deformity.
  • Spinal instability.
  • Paraspinal abscess or septicemia.
  • Relapse of infection.

Recent Advances and Recommendations

  • Minimally Invasive Surgery (MIS):
    • Preferred when feasible, due to lower morbidity and faster recovery.
  • Imaging Advances:
    • MRI techniques can differentiate between infection and malignancy more effectively.
  • Consensus Guidelines (e.g., EANS recommendations):
    • Provide structured thresholds for surgical indications and antibiotic durations.

Challenges in Management

  • Delayed diagnosis due to non-specific symptoms.
  • Rising antimicrobial resistance.
  • Balancing the risks of surgery in medically fragile patients.

Conclusion

Spondylodiscitis management requires individualized care based on patient presentation, infection severity, and comorbidities. The integration of targeted antibiotics, timely surgical intervention when indicated, and structured follow-up ensures optimal outcomes. Ongoing research is essential to refine treatment protocols and improve patient care.

Delphi consensus studies

The de novo non-specific spinal infection managements (spondylodiscitis – SD) remains inconsistent due to varying clinical practices and a lack of high-level evidence, particularly regarding the indications for surgery.

Research question: This study aimed to develop consensus recommendations for spondylodiscitis diagnosis and spondylodiscitis management, addressing diagnostic modalities, surgical indications, and spondylodiscitis treatment strategies.

A Delphi consensus study was conducted with 26 experts from the European Association of Neurosurgical Societies (EANS). Sixtytwo statements were developed on diagnostic workup, management decisions, surgical techniques, non-surgical treatment, and follow-up and submitted to the panel of experts.

Consensus was reached on 38 of 62 statements. MRI was confirmed as the gold standard for diagnosis. Regarding surgical indications, the panel agreed that any new neurological deficit, even subtle, warrants surgical consideration. Motor deficits with a motor score (MRC) below 4 and bladder or bowel dysfunction were unanimously considered clear indications for surgery. For spinal deformity and instability, thresholds such as kyphosis >20°, scoliosis >10°, and vertebral body collapse >50% were established to guide surgical decision-making. Minimally invasive surgery (MIS) was endorsed whenever feasible, and a 12 week antibiotic treatment regimen was favored in cases of complicated infections.

This EANS consensus provides updated recommendations for spondylodiscitis management, incorporating recent evidence on improved outcomes with surgical therapy. While these guidelines offer a more structured approach to clinical decision-making, further research is required to optimize surgical timing and validate the long-term impact of these treatment strategies 1).

This study successfully tackles a clinically significant challenge by providing structured recommendations for the diagnosis and management of de novo non-specific spinal infections. While the use of the Delphi method lends credibility, the reliance on expert opinion, incomplete consensus, and limited global representation are notable limitations. Nonetheless, it serves as an important step towards standardizing care for spinal infections and highlights the urgent need for further research to validate and refine these recommendations.

Systematic review and meta-analysis

Thavarajasingam et al. aimed to compare the mortality, relapse rate, and length of hospital stay of conservative versus early surgical treatment of pyogenic spondylodiscitis. All major databases were searched for original studies, which were evaluated using a qualitative synthesis, meta-analyses, influence, and regression analyses. The meta-analysis, with an overall pooled sample size of 10,954 patients from 21 studies, found that the pooled mortality among the early surgery patient subgroup was 8% versus 13% for patients treated conservatively. The mean proportion of relapse/failure among the early surgery subgroup was 15% versus 21% for the conservative treatment subgroup. Further, it concluded that early surgical treatment, when compared to conservative management, is associated with a 40% and 39% risk reduction in relapse/failure rate and mortality rate, respectively, and a 7.75 days per patient reduction in length of hospital stay (p < 0.01). The meta-analysis demonstrated that early surgical intervention consistently significantly outperforms conservative management in relapse/failure and mortality rates, and length of stay, in patients with pyogenic spondylodiscitis 2)

Thavarajasingam et al.’s systematic review and meta-analysis provide compelling evidence that early surgical intervention significantly outperforms conservative management in pyogenic spondylodiscitis, with reductions in mortality, relapse rates, and hospital stays. However, limitations such as heterogeneity, reliance on observational data, and a lack of long-term outcome evaluation temper the strength of its conclusions. Future studies should address these gaps to enhance the robustness and applicability of the findings across diverse patient populations and healthcare environments.

Systematic review

A population-based study from Denmark showed that the incidence of spondylodiscitis rose from 2.2 to 5.8 per 100 000 persons per year over the period 1995-2008; the age-standardized incidence in Germany has been estimated at 30 per 250 000 per year on the basis of data from the Federal Statistical Office (2015). The early diagnosis and treatment of this condition are essential to give the patient the best chance of a good outcome, but these are often delayed because it tends to present with nonspecific manifestations, and fever is often absent.

Herren et al published an article based on a systematic search of Medline and the Cochrane Library for the period January 2009 to March 2017. Of the 788 articles identified, 30 publications were considered.

The goals of treatment for spondylodiscitis are to eliminate infection, restore functionality of the spine, and relieve pain. Magnetic resonance imaging (MRI) remains the gold standard for the radiological demonstration of this condition, with 92% sensitivity and 96% specificity. It also enables visualization of the spatial extent of the infection and of abscess formation (if present). The most common bacterial cause of spondylodiscitis in Europe is Staphylococcus aureus, but tuberculous spondylodiscitis is the most common type worldwide. Antibiotic therapy is a pillar of treatment for spondylodiscitis and should be a part of the treatment in all cases. Neurologic deficits, sepsis, an intraspinal empyema, the failure of conservative treatment, and spinal instability are all indications for surgical treatment.

The quality of life of patients who have been appropriately treated for spondylodiscitis has been found to be highly satisfactory in general, although back pain often persists. The risk of recurrence increases in the presence of accompanying illnesses such as diabetes mellitus, renal failure, or undrained epidural abscesses 3)

Literature review with clinical recommendations

Five influential studies on PS that have the potential to shape current practice in spinal infections were selected and reviewed. Each study was chosen for its contribution to a critical phase in PS management: diagnosis, imaging, surgical vs conservative treatment, and antibiotic duration. Recommendations were graded as strong or conditional following the GRADE methodology.

Five studies were highlighted. Article 1: Pluemer et al introduced the Spinal Infection Treatment Evaluation (SITE) Score, a novel scoring tool for standardizing treatment decision-making. Conditional recommendation to incorporate the SITE Score or SISS Score for improved treatment outcomes. Article 2: Maamari et al conducted a meta-analysis comparing imaging modalities, with conditional recommendation to consider 18F-FDG PET/CT to diagnosis PS as an adjunct to MRI which remains the gold standard. Article 3: Thavarajasingam et al demonstrated the potential survival benefit of early surgery in specific PS cases, leading to a strong recommendation for early intervention in appropriate patients. Article 4: Neuhoff et al compared conservative and surgical treatments in well-resourced settings, concluding a strong recommendation for early surgery in appropriate patients. Article 5: Bernard et al evaluated antibiotic treatment duration, with a conditional recommendation for a 6-week course in confirmed cases, based on comparable efficacy to a 12-week regimen.

Management of PS remains complex and varied. This perspective provides spine surgeons with evidence-based recommendations to enhance standardization and effectiveness in clinical practice 4).

The study represents a valuable effort to synthesize impactful research on PS management and translate it into actionable recommendations. However, its narrow scope, reliance on conditional recommendations, and limited discussion of implementation challenges restrict its immediate applicability in diverse settings. Future efforts should expand the evidence base, address variability in resources, and validate the proposed guidelines to enhance their utility in standardizing and improving care for pyogenic spondylodiscitis.

1)

Kramer A, Thavarajasingam SG, Neuhoff J, Davies B, Barbagallo G, Debono B, Depreitere B, Eicker SO, Gabrovsky N, Gandia-Gonzalez ML, Ivanov M, Kaiser R, Kaprovoy S, Konovalov N, Lafuente J, Maciejczak A, Meyer B, Pereira P, Petrova Y, Peul WC, Reizinho C, Ryang YM, Sampron N, Schär R, Tessitore E, Thomé C, Timothy J, Vleggeert-Lankamp C, Demetriades AK, Shiban E, Ringel F. Diagnosis and management of de novo non-specific spinal infections: European Association of Neurosurgical Societies (EANS) Spine Section Delphi consensus recommendations. Brain Spine. 2024 Dec 31;5:104178. doi: 10.1016/j.bas.2024.104178. PMID: 39866360; PMCID: PMC11763570.
2)

Thavarajasingam SG, Vemulapalli KV, Vishnu K S, Ponniah HS, Vogel AS, Vardanyan R, Neuhoff J, Kramer A, Shiban E, Ringel F, Demetriades AK, Davies BM. Conservative versus early surgical treatment in the management of pyogenic spondylodiscitis: a systematic review and meta-analysis. Sci Rep. 2023 Sep 20;13(1):15647. doi: 10.1038/s41598-023-41381-1. PMID: 37730826; PMCID: PMC10511402.
3)

Herren C, Jung N, Pishnamaz M, Breuninger M, Siewe J, Sobottke R. Spondylodiscitis: Diagnosis and Treatment Options. Dtsch Arztebl Int. 2017 Dec 25;114(51-52):875-882. doi: 10.3238/arztebl.2017.0875. PMID: 29321098; PMCID: PMC5769318.
4)

Bigdon SF, Vialle E, Dandurand C, Scherer J, Camino-Willhuber G, Joaquim AF, Chhabra HS, El-Sharkawi M, Bransford R, Fisher CG, Schnake KJ, Schroeder GD; AO KF Trauma and Infection Members. Streamlining the Journey of Research Into Clinical Practice: Making Your Patients and Practice Flourish Evaluation and Treatment of Pyogenic Spondylodiscitis of the Spine: AO Spine Knowledge Forum Trauma and Infection. Global Spine J. 2025 Jan 24:21925682251316814. doi: 10.1177/21925682251316814. Epub ahead of print. PMID: 39852953; PMCID: PMC11760070.

Neuroendoscopic lavage for periventricular-intraventricular hemorrhage

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Neuroendoscopic lavage for periventricular-intraventricular hemorrhage

J.Sales-Llopis

Neurosurgery Department, General University Hospital Alicante, Spain

Neuroendoscopic lavage for periventricular-intraventricular hemorrhage (PIVH) is an emerging surgical approach aimed at improving the clearance of intraventricular blood clots, reducing hydrocephalus, and improving neurological outcomes in affected patients. Here’s an overview of the technique and its implications:

Indications

Neuroendoscopic lavage is typically indicated in cases of:

1. Severe intraventricular hemorrhage (IVH) associated with periventricular hemorrhage.

2. Obstructive hydrocephalus caused by blood clots in the ventricular system.

3. Cases where conservative management or external ventricular drainage (EVD) alone is insufficient for clot resolution.

Procedure

The procedure involves using a neuroendoscope to directly access the ventricular system. Key steps include:

1. Ventricular access: A burr hole is created to access the affected ventricle under neuronavigation guidance.

2. Neuroendoscopic insertion: A flexible or rigid endoscope is introduced into the ventricle.

3. Clot removal: Blood clots are aspirated or fragmented under direct visualization using specialized instruments or saline irrigation.

4. Irrigation: The ventricles are irrigated with warmed saline to ensure clearance of debris and residual clots.

5. EVD placement: Often, an external ventricular drain is left in place to monitor intracranial pressure (ICP) and facilitate further drainage of blood or cerebrospinal fluid (CSF).

Advantages

1. Enhanced clot clearance: Direct visualization allows for targeted and effective removal of clots, reducing clot burden and the associated risk of persistent hydrocephalus.

2. Reduced inflammation: By removing blood and its breakdown products, neuroendoscopic lavage may decrease the inflammatory response that contributes to ventricular scarring and hydrocephalus.

3. Minimally invasive: Compared to open surgical approaches, it involves smaller incisions and reduced disruption of brain tissue.

4. Potential for improved outcomes: Studies have suggested better neurological recovery and lower rates of shunt dependency in some cases.

Challenges and Limitations

1. Technical expertise: The procedure requires advanced neuroendoscopic skills and specialized equipment.

2. Risks: Complications include infection, hemorrhage, or damage to ventricular structures.

3. Not universally applicable: It is most effective in cases where clot consistency and location are suitable for endoscopic removal.

4. Limited evidence: While promising, robust clinical trials are needed to establish its efficacy compared to standard treatments.

Outcomes

– Early studies indicate that neuroendoscopic lavage can reduce mortality and improve functional outcomes in patients with PIVH and hydrocephalus.

– It may decrease the need for permanent CSF shunting and lower rates of complications related to prolonged EVD use.

Future Directions

1. Standardization: Developing standardized protocols for patient selection and procedural techniques.

2. Technological advances: Innovations in endoscopic tools and navigation systems to enhance safety and efficacy.

3. Long-term studies: Further research to evaluate the long-term benefits and cost-effectiveness of neuroendoscopic lavage.

The current neurosurgical procedure for periventricular-intraventricular hemorrhage resulting in posthemorrhagic hydrocephalus (PHH) seeks to reduce intracranial pressure with temporary and then Cerebrospinal fluid shunt. In contrast, neuroendoscopic lavage (NEL) directly addresses the intraventricular blood that is hypothesized to damage the ependyma and parenchyma, leading to ventricular dilation and hydrocephalus.

Systematic reviews

Wassef et al. conducted a systematic review of the literature on neuroendoscopic lavage in IVH of prematurity to examine data on the choice of neuroendoscope and outcomes regarding shunt rate. They then collected manufacturer data on neuroendoscopic devices, including inflow and outflow mechanisms, working channel specifications, and tools compatible with the working channel. We paired this information with the advantages and disadvantages reported in the literature and observations from the experiences of pediatric neurosurgeons from several institutions to provide a pragmatic evaluation of international clinical experience with each neuro endoscope in NEL.

Eight studies were identified; four neuroendoscopes have been used for NEL as reported in the literature. These include the Karl Storz Flexible Neuroendoscope, LOTTA® system, GAAB system, and Aesculap MINOP® system. The LOTTA® and MINOP® systems were similar in setup and instrument options. Positive neuroendoscope features for NEL include increased degrees of visualization, better visualization with the evolution of light and camera sources, the ability to sterilize with autoclave processes, balanced inflow and outflow mechanisms via separate channels, and a working channel. Neuroendoscope disadvantages for NEL may include special sterilization requirements, large outer diameter, and limitations in working channels.

A neuroendoscope integrating continuous irrigation, characterized by measured inflow and outflow via separate channels and multiple associated instruments, appears to be the most commonly used technology in the literature. As neuro endoscopes evolve, maximizing clear visualization, adequate inflow, measured outflow, and large enough working channels for paired instrumentation while minimizing the footprint of the outer diameter will be most advantageous when applied for NEL in premature infants 1).

Wassef et al.’s review provides an essential contribution to the understanding of neuroendoscopic technology in the context of NEL for IVH in premature infants. While the study outlines critical device features and evolving trends, its conclusions are constrained by limited data and a lack of quantitative analysis. Nevertheless, the work highlights key priorities for technological and clinical advancement, serving as a foundation for future research and innovation in this challenging yet promising area of pediatric neurosurgery.

Retrospective cohort studies

The records of patients with a diagnosis of grade III or IV IVH were reviewed between September 2022 and February 2024. The Papile-Burstein classification grade was determined on cranial ultrasonography. Demographic information collected included gestational age, birth weight, weight at the time of surgical intervention, infection confirmed with CSF, and hemorrhage. Standard local guidelines for temporary (CSF reservoir) and permanent (shunt or endoscopic third ventriculostomy (ETV) CSF diversion was implemented. Warmed Lactated Ringer’s was utilized for NEL. The primary outcome was the need for permanent CSF diversion (shunt or ETV).

Twenty consecutive patients with grade III or IV IVH complicated by PHH were identified. Twelve patients underwent CSF reservoir placement and NEL, 4 underwent CSF reservoir placement only, 1 underwent shunt placement only, and 3 did not require neurosurgical intervention. Of the 12 patients who underwent reservoir placement and NEL, 8 (67%) ultimately met the criteria for permanent CSF diversion compared with 2 of 4 (50%) who underwent CSF reservoir placement only. The mean gestational age at birth, birth weights, and age/weight at the time of temporary CSF diversion were similar across groups. The average time interval between temporary and permanent CSF diversion was longer in patients who underwent NEL (2.5 months for shunt and 6.5 months for ETV) compared with CSF reservoir placement only (1.1 months).

NEL is an innovative alternative for the treatment of PHH of prematurity. Flanders et al. from the New York University Grossman School of Medicine, Department of Pediatrics, Children’s Hospital of Philadelphia, Pennsylvania established an endoscopic lavage program at their institution and herein report the first published account in the United States of the feasibility of NEL for PHH 2).

Flanders et al. provide an intriguing glimpse into the potential of neuroendoscopic lavage for managing PHH of prematurity. While the approach is innovative and technically feasible, the study’s small sample size, lack of randomization, and limited long-term outcome data temper the enthusiasm for immediate adoption. Further research is essential to confirm the efficacy, safety, and cost-effectiveness of NEL, ensuring its role as a viable alternative or adjunct to existing treatment paradigms for PHH.

Comparative retrospective studies

Between August 2010 and December 2012 (29 months), 19 neonates with posthemorrhagic hydrocephalus underwent neuroendoscopic lavage for removal of intraventricular blood remnants. During a similar length of time (29 months) from March 2008 to July 2010, 10 neonates were treated conventionally, initially using temporary CSF diversion via lumbar punctures, a ventricular access device, or an external ventricular drain. Complications and shunt dependency rates were evaluated retrospectively. Results The patient groups did not differ regarding gestational age and birth weight. In the endoscopy group, no relevant procedure-related complications were observed. After the endoscopic lavage, 11 (58%) of 19 patients required a later shunt insertion, as compared with 100% of infants treated conventionally (p < 0.05). Endoscopic lavage was associated with fewer numbers of overall necessary procedures (median 2 vs 3.5 per patient, respectively; p = 0.08), significantly fewer infections (2 vs 5 patients, respectively; p < 0.05), and supratentorial multiloculated hydrocephalus (0 vs 4 patients, respectively; p < 0.01) [corrected]. Conclusions Within the presented setup the authors could demonstrate the feasibility and safety of neuro-endoscopic lavage for the treatment of posthemorrhagic hydrocephalus in neonates with IVH. The nominally improved results warrant further verification in a multicenter, prospective study 3).

The study provides a compelling case for the feasibility and safety of neuroendoscopic lavage in neonates with posthemorrhagic hydrocephalus. The lower rates of shunt dependency, infections, and multiloculated hydrocephalus are encouraging and suggest a potential benefit of NEL over conventional management.

However, the study’s limitations, particularly its retrospective design, small sample size, and lack of long-term outcomes, necessitate further investigation. A multicenter, prospective study is critical to validate these findings, optimize patient selection, and determine the technique’s broader applicability and impact on long-term neurodevelopment.

This study represents a promising step forward, but cautious interpretation is essential until more robust evidence emerges.

1)

Wassef CE, Thomale UW, LoPresti MA, DeCuypere MG, Raskin JS, Mukherjee S, Aquilina K, Lam SK. Experience in endoscope choice for neuroendoscopic lavage for intraventricular hemorrhage of prematurity: a systematic review. Childs Nerv Syst. 2024 Aug;40(8):2373-2384. doi: 10.1007/s00381-024-06408-6. Epub 2024 May 27. PMID: 38801444; PMCID: PMC11269422.
2)

Flanders TM, Hwang M, Julian NW, Sarris CE, Flibotte JJ, DeMauro SB, Munson DA, Heimall LM, Collins YC, Bamberski JM, Sturak MA, Storm PB, Lang SS, Heuer GG. Neuroendoscopic lavage for posthemorrhagic hydrocephalus of prematurity: preliminary results at a single institution in the United States. J Neurosurg Pediatr. 2025 Jan 24:1-8. doi: 10.3171/2024.10.PEDS24119. Epub ahead of print. PMID: 39854725.
3)

Schulz M, Bührer C, Pohl-Schickinger A, Haberl H, Thomale UW. Neuroendoscopic lavage for the treatment of intraventricular hemorrhage and hydrocephalus in neonates. J Neurosurg Pediatr. 2014 Jun;13(6):626-35. doi: 10.3171/2014.2.PEDS13397. Epub 2014 Apr 4. Erratum in: J Neurosurg Pediatr. 2014 Jun;13(6):706. PMID: 24702621.

Subpial corticectomy simulation

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Subpial corticectomy simulation

Subpial corticectomy simulation is a highly specialized procedure that involves recreating the surgical process of a subpial corticectomy in a controlled, virtual, or educational environment. The aim of this simulation can be to enhance surgical skills, train residents, or explore surgical strategies before performing on actual patients.

Objectives of Simulation

– Skill Acquisition: To train neurosurgeons or trainees in performing precise cortical resections.

– Preoperative Planning: To visualize and plan the approach to lesions in eloquent brain areas.

– Patient Safety: To practice techniques in a risk-free environment.

– Understanding Neuroanatomy: To study cortical and subcortical structures in detail.

Tools and Technologies

– 3D Imaging Platforms: Use of advanced imaging technologies like MRI, fMRI, or DTI integrated into surgical simulation software.

– Virtual Reality (VR) Systems: Platforms like VR surgical simulators to recreate the tactile feedback and visual representation of the brain.

– NeuroNavigation Systems: Integrating systems like Medtronic StealthStation or Brainlab for accurate anatomical representation.

– Augmented Reality (AR): Overlaying virtual structures onto real-world models for enhanced surgical guidance.

– Haptic Feedback Devices: To mimic the feel of cutting or coagulating brain tissue.

Simulation Workflow

1. Data Acquisition:

  1. Collect patient-specific imaging data (MRI, CT) for realistic brain modeling.

2. Virtual Environment Setup:

  1. Load imaging data into the simulation software.
  2. Configure tools and settings specific to the procedure.

3. Preoperative Planning:

  1. Identify the target area for corticectomy and any nearby eloquent regions.
  2. Simulate mapping techniques (e.g., motor, sensory cortex).

4. Surgical Simulation:

  1. Practice opening the dura, identifying gyri and sulci, and using subpial dissection techniques.
  2. Simulate use of instruments like suction, bipolar coagulation, and microdissectors.

5. Complication Management:

  1. Train for real-life scenarios like unexpected bleeding, eloquent cortex compromise, or equipment failure.

6. Postoperative Analysis:

  1. Evaluate resection accuracy, complication rates, and adherence to surgical plans.

Educational Integration

– Team-Based Training: Incorporate anesthetists, nursing staff, and assistants into simulations to mimic the operating room dynamic.

– Feedback Mechanisms: To evaluate performance, use metrics like accuracy, time taken, and safety.

– Case Reviews: Discuss simulated cases in grand rounds or workshops.

Future Directions

– AI Integration: Use AI to guide surgical decision-making based on simulation performance.

– Remote Simulation Platforms: Allow surgeons worldwide to train collaboratively in a shared virtual space.

– Personalized Simulations: Tailor models to patient-specific anatomy and pathology for preoperative rehearsals.

Subpial corticectomy involving complete lesion resection while preserving pial membranes and avoiding injury to adjacent normal tissues is an essential bimanual task necessary for neurosurgical trainees to master. Almansouri et al. sought to develop an ex vivo calf brain corticectomy simulation model with continuous assessment of neurosurgical instruments movement during the simulation. A case series study of skilled participants was performed to assess face and content validity to gain insights into the utility of this training platform, along with determining if skilled and less skilled participants had statistical differences in validity assessment.

An ex vivo calf brain simulation model was developed in which trainees performed a subpial corticectomy of three defined areas. A case series study assessed the face and content validity of the model using 7-point Likert scale questionnaires.

Twelve skilled and 11 less skilled participants were included in this investigation. Overall median scores of 6.0 (range 4.0-6.0) for face validity and 6.0 (range 3.5-7.0) for content validity were determined on the 7-point Likert scale, with no statistical differences between skilled and less skilled groups identified.

A novel ex vivo calf brain simulator was developed to replicate the subpial resection procedure and demonstrated face and content validity 1)

Almansouri et al.’s study represent a valuable contribution to neurosurgical training, offering a novel approach to simulating subpial corticectomy. While the model demonstrates face and content validity, further research is needed to establish its broader applicability and impact on neurosurgical education. Incorporating additional validation metrics and expanding the study’s scope could significantly enhance the simulator’s utility as a training tool.

Santos et al. describe a cadaveric model simulating the resection of a temporo-insular low-grade glioma. Klingler method technique was used to fix the cadaver head before injecting red and blue colorants for a realistic vascular appearance. The hemisphere was frozen for white matter tract dissection. Tractography and intraoperative eloquent areas were extrapolated from a glioma patient by using a neuronavigation system. Then, a frontotemporal craniotomy was performed through a question mark incision, exposing the inferior temporal gyrus up to the middle frontal gyrus. After cortical anatomic landmark identification, eloquent areas were extrapolated creating a simulated functional cortical map. Then, trans opercular non eloquent frontal and temporal corticectomies were performed, followed by subpial resection. Detailed identification of Sylvian vessels and insular cortex was demonstrated. Anatomic resection limits were exposed, and implicated white matter bundles, uncinate, and fronto-occipital fascicles, were identified running through the temporal isthmus. Finally, a temporo-mesial resection was performed. In summary, this model provides a simple, cost-effective, and very realistic simulation of a trans-opercular approach to the insula, allowing the development of surgical skills needed to treat insular tumors in a safe environment. Besides, the integration of simulated navigation has proven useful in better understanding the complex white matter anatomy involved. Cadaver donation, subject or relatives, includes full consent to publish the images. For this video, no ethics committee approval was needed. Images correspond to a cadaver head donation. Cadaver donation, subject or relatives, includes full consent for any scientific purposes involving the corpse. The consent includes an image or video recording. Regarding the intraoperative surgical video and tractography, the patient gave written consent for scientific divulgation before surgery 2).

This cadaveric-based model, as described by Santos et al., is an exemplary tool for advancing neurosurgical education. Despite some inherent limitations, it provides a robust framework for learning the surgical nuances of temporo-insular tumor resections, fostering both anatomical understanding and technical proficiency in a controlled, ethical, and cost-effective manner.

1)

Almansouri A, Abou Hamdan N, Yilmaz R, Tee T, Pachchigar P, Eskandari M, Agu C, Giglio B, Balasubramaniam N, Bierbrier J, Collins DL, Gueziri HE, Del Maestro RF. Continuous Instrument Tracking in a Cerebral Corticectomy Ex Vivo Calf Brain Simulation Model: Face and Content Validation. Oper Neurosurg (Hagerstown). 2024 Jul 1;27(1):106-113. doi: 10.1227/ons.0000000000001044. Epub 2024 Jan 8. PMID: 39813069.
2)

Santos C, Velasquez C, Esteban J, Fernandez L, Mandonnet E, Duffau H, Martino J. Transopercular Insular Approach, Overcoming the Training Curve Using a Cadaveric Simulation Model: 2-Dimensional Operative Video. Oper Neurosurg (Hagerstown). 2021 Nov 15;21(6):E561-E562. doi: 10.1093/ons/opab342. PMID: 34561696.

Spinal schwannoma

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Spinal schwannoma

J.Sales-Llopis

Neurosurgery Department, General University Hospital Alicante, Spain

Latest Pubmed Articles

Definition

Spinal schwannomas are well-described slow growing benign spinal tumors of the peripheral nervous system, arising from Schwann cells.

Epidemiology

see Spinal schwannoma epidemiology.

Classification

see Spinal Schwannoma Classification.

Associations

The vast majority of spinal schwannomas are solitary and sporadic (95%) 10.

However, there is an association with neurofibromatosis type 2 (NF2). In patients with NF2, almost all spinal nerve root tumors are schwannomas or mixed tumors. In a young adult without the NF2 mutation, the finding of multiple schwannomas may meet the criteria for schwannomatosis.

Pathology

Antoni A and Antoni B tissue.

Clinical features

Patients with nonsyndromic spinal schwannoma usually present to hospital with local pain and neurological deficit that exacerbate over time.

Early symptoms are often radicular.

Neurological deficits develop late.

Tumor may cause radiculopathy, myelopathy, radiculomyelopathy or cauda equina syndrome.

Diagnosis

Spinal schwannoma diagnosis

Differential diagnosis

Spinal Schwannoma differential diagnosis

Treatment

see Spinal schwannoma treatment.

Outcome

Spinal schwannoma recurrence is rare after total excision (except in neurofibromatosis).

The risk for motor deficit is higher for schwannomas than for neurofibromas, for cervical vs. lumbar tumors, and for cervical tumors wiyh extradural extension.

Systematic Review and Meta-Analysis

Alvarez-Crespo et al. conducted a systematic review and meta-analysis under the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A search of bibliographic databases from January 1, 2001, to May 31, 2021, yielded 4489 studies. Twenty-six articles were included in our final qualitative systematic review and quantitative meta-analysis.

Analysis of 2542 adult patients’ data from 26 included studies showed that 53.5% were male, and the mean age ranged from 35.8 to 57.1 years. The most common tumor location was the cervical spine (34.2%), followed by the thoracic spine (26.2%) and the lumbar spine (18.5%). Symptom severity was the most common indicator for surgical treatment, with the most common symptoms being segmental back pain, sensory/motor deficits, and urinary dysfunction. Among all patients analyzed, 93.8% were treated with gross total resection, which was associated with a better prognosis and less chance of recurrence than subtotal resection. The posterior approach was the most common (87.4% of patients). The average operative time was 4.53 hours (95% confidence interval [CI], 3.18-6.48); the average intraoperative blood loss was 451.88 mL (95% CI, 169.60-1203.95). The pooled follow-up duration was 40.6 months (95% CI, 31.04-53.07). The schwannoma recurrence rate was 5.3%. Complications were particularly low and included cerebrospinal fluid leakage, wound infection, and sensory-motor deficits. Most of the patients experienced complete recovery or significant improvement of preoperative neurological deficits and pain symptoms.

The analysis suggests that segmental back pain, sensory/motor deficits, and urinary dysfunction are the most common symptoms of spinal schwannomas. Surgical resection is the treatment of choice with overall good reported outcomes and particularly low complication rates. gross total resection offers the best prognosis with the slightest chance of tumor recurrence and minimal risk of complications 1).

Case series

see Spinal Schwannoma Case Series.

Case reports

see Spinal Schwannoma Case Reports.

1)

Alvarez-Crespo DJ, Conlon M, Kazim SF, Skandalakis GP, Bowers CA, Chhabra K, Tarawneh O, Arbuiso S, Cole KL, Dominguez J, Dicpinigaitis AJ, Vellek J, Thommen R, Bisson EF, Couldwell WT, Cole CD, Schmidt MH. Clinical Characteristics and Surgical Outcomes of 2542 Patients with Spinal Schwannomas: A Systematic Review and Meta-Analysis. World Neurosurg. 2024 Feb;182:165-183.e1. doi: 10.1016/j.wneu.2023.11.090. Epub 2023 Nov 24. PMID: 38006933.

Regorafenib for glioblastoma

by

Regorafenib for glioblastoma

J.Sales-Llopis

Neurosurgery Department, General University Hospital Alicante, Spain

Regorafenib, a multi-kinase inhibitor, has emerged as a potential therapeutic option for glioblastoma, particularly in cases where standard treatments such as surgery, radiation, and temozolomide chemotherapy have failed.

Mechanism of Action

Regorafenib targets multiple receptor tyrosine kinases involved in tumor proliferation, angiogenesis, and the tumor microenvironment, including:

VEGFR (Vascular Endothelial Growth Factor Receptors)

PDGFR (Platelet-Derived Growth Factor Receptors)

FGFR (Fibroblast Growth Factor Receptors)

KIT, RET, and BRAF These pathways are often dysregulated in glioblastoma, promoting tumor growth and resistance to standard therapies.

Clinical Evidence

REGOMA Trial (2019): A phase II clinical trial evaluated regorafenib in patients with recurrent glioblastoma:

Results: The study showed an improvement in overall survival (OS) compared to lomustine, a standard second-line therapy. Median OS for regorafenib was 7.4 months versus 5.6 months for lomustine. Implications: This result demonstrated the potential of regorafenib as a viable treatment option in recurrent settings. Ongoing Studies:

Further trials (e.g., phase III) are assessing its safety, efficacy, and potential biomarkers for predicting response. Studies are exploring combination therapies, such as regorafenib with immunotherapy, to overcome resistance mechanisms.

Potential Benefits

Angiogenesis Inhibition: Glioblastoma’s hallmark feature is its high vascularity, making anti-angiogenic therapy a promising strategy. Tumor Microenvironment Modulation: Regorafenib can alter the tumor’s supportive environment, potentially enhancing the efficacy of other treatments. Side Effects Regorafenib is associated with several adverse effects that require careful management, including:

Hypertension Hand-foot skin reactions Fatigue Diarrhea Hepatotoxicity Future Directions Biomarker Development: Identifying patients who would benefit most from regorafenib based on genetic and molecular tumor profiles. Combination Therapies: Combining regorafenib with checkpoint inhibitors, radiotherapy, or other targeted agents. Optimization of Dosing: Balancing efficacy with tolerability, particularly in patients with fragile health due to glioblastoma.

Meta-analysis of randomized controlled clinical trials

A meta-analysis, based on searches in PubMed and Web Of Science, evaluated 12 randomized controlled trials (RCTs) examining PKIs in patients with newly diagnosed or recurrent GBM. Pooled analysis of shared clinical outcomes – progression-free survival (PFS) and overall survival (OS) – revealed a lack of significant improvements with the use of PKIs. In newly diagnosed GBM, no significant differences were observed in median [-1.02 months, 95% confidence interval (CI), -2.37-0.32, p=0.14] and pooled [hazard ratio (HR)=1.13, 95% CI, 0.95-1.35, p=0.17) OS, or in median (0.34 months, 95% CI, -0.9-1.58, p=0.60) and pooled (HR=0.98, 95% CI, 0.76-1.27, p=0.89) PFS, when comparing PKI addition to standard chemo-radiotherapy versus chemo-radiotherapy alone. In recurrent GBM, three different analyses were conducted: PKI versus other treatments, PKI combined with other treatments versus those treatments alone, PKI versus PKI combined with other treatments. Also, across these analyses, no significant clinical benefits were found. For instance, when comparing PKI treatment with other treatments, median OS and PFS showed no significant difference (-0.78 months, 95% CI, -2.12-0.55, p=0.25; -0.23 months, 95% CI, -0.79-0.34, p=0.43, respectively), and similar non-significant results were observed in the pooled analyses (OS: HR=0.89, 95% CI, 0.59-1.32, p=0.55; PFS: HR=0.83, 95% CI, 0.63-1.11, p=0.21). Despite these overall negative findings, some data indicate improved clinical outcomes in a subset of GBM patients treated with certain PKIs (i.e., regorafenib) and encourage further research to identify PKIs with better blood-brain barrier penetration and lower risk for resistance development 1)

This meta-analysis underscores the limited efficacy of current PKIs in GBM, despite rigorous methodological approaches. While the findings are largely negative, the identification of potential benefits in specific patient subsets offers a pathway for refining PKI therapy. Future research should prioritize biomarker-driven trials, focus on agents with enhanced BBB penetration, and explore novel combination strategies. The ultimate challenge lies in overcoming the heterogeneity and treatment resistance characteristic of GBM, which remain formidable barriers to improving patient outcomes.

Systematic Reviews

Schettini et al. conducted a systematic review and Bayesian trial-level network metaanalysis (NMA) to identify the regimens associated with the best outcomes. The primary endpoint was overall survival (OS). Secondary endpoints were progression-free survival (PFS) and overall response rates (ORR). They estimated separate treatment rankings based on the surface under the cumulative ranking curve values. Only phase II/III prospective comparative trials were included.

Twenty-four studies (3733 patients and 27 different therapies) were ultimately included. Twenty-three different regimens were compared for OS, 21 for PFS, and 26 for ORR. When taking lomustine as a common comparator, only regorafenib was likely to be significantly superior in terms of OS (hazard ratio: 0.50, 95% credible interval: 0.33-0.75). Regorafenib was significantly superior to other 16 (69.6%) regimens, including NovoTTF-100A, bevacizumab monotherapy, and several bevacizumab-based combinations. Regarding PFS and ORR, no treatment was clearly superior to the others.

This NMA supports regorafenib as one of the best available options for relapsing/refractory glioblastoma. Lomustine, NovoTTF-100A, and bevacizumab emerge as other viable alternative regimens. However, evidence on regorafenib is controversial at best. Moreover, most studies were underpowered, with varying inclusion criteria and primary endpoints, and no longer adapted to the most recent glioblastoma classification. A paradigmatic change in clinical trials’ design for relapsing/refractory glioblastoma and more effective treatments are urgently required 2)

Schettini et al.’s systematic review and Bayesian NMA make an important contribution to understanding the relative efficacy of available therapies for relapsing/refractory GBM, particularly by highlighting regorafenib as a potentially effective option. However, the study is hindered by limitations inherent to the included trials and the analytical framework, including the heterogeneity of studies, underpowered designs, and outdated glioblastoma classifications.

The findings underscore the pressing need for a paradigm shift in GBM clinical trials. Future research should prioritize large, well-powered, multicenter trials incorporating molecularly stratified patient cohorts and harmonized endpoints. Additionally, the exploration of novel therapeutic strategies is critical to advancing the treatment landscape for this devastating disease. While regorafenib appears promising, its clinical utility must be validated in robust, contemporary trials to establish its place in the therapeutic arsenal for GBM.

Retrospective Studies

In a retrospective study, Kebir et al. investigated the efficacy and radiographic tumor growth patterns of regorafenib in recurrent high-grade astrocytoma.

They screened for patients with a high-grade astrocytoma in whom regorafenib was administered for at least 4 weeks. We assessed treatment efficacy in terms of progression-free survival (PFS), overall survival, and adverse events defined by Common Toxicity Criteria (CTC). In addition, radiographic tumor growth patterns were determined at baseline and recurrence.

A total of 6 patients met the eligibility criteria. The number of recurrences prior to regorafenib varied between 2 and 6. Patients were on regorafenib treatment for at least 4 weeks and maximally 14 weeks. Median PFS was 3.5 months and ranged from 2.0 to 4.0 months. Radiographic response was progressive disease in all patients with an objective response rate of 0%. CTC°3 adverse events were observed in all but one patient. The most common radiographic growth pattern was local with no change in growth pattern at recurrence. An infiltrative tumor growth was not induced in any patient.

This retrospective study indicates the very poor performance of regorafenib in recurrent high-grade astrocytoma with a fairly high number of CTC°3 adverse events. In addition, regorafenib does not seem to bear a potential for infiltrative tumor growth promotion 3).

1)

Pinto-Fraga J, García-Chico C, Lista S, Lacal PM, Carpenzano G, Salvati M, Santos-Lozano A, Graziani G, Ceci C. protein kinase inhibitors as Targeted therapy for glioblastoma: A meta-analysis of randomized controlled clinical trials. Pharmacol Res. 2024 Dec 3:107528. doi: 10.1016/j.phrs.2024.107528. Epub ahead of print. PMID: 39637954.
2)

Schettini F, Pineda E, Rocca A, Buché V, Donofrio CA, Mazariegos M, Ferrari B, Tancredi R, Panni S, Cominetti M, Di Somma A, González J, Fioravanti A, Venturini S, Generali D. Identifying the best treatment choice for relapsing/refractory glioblastoma: a systematic review with multiple Bayesian network meta-analyses. Oncologist. 2024 Dec 14:oyae338. doi: 10.1093/oncolo/oyae338. Epub ahead of print. PMID: 39674575.
3)

Kebir S, Rauschenbach L, Radbruch A, Lazaridis L, Schmidt T, Stoppek AK, Pierscianek D, Stuschke M, Forsting M, Sure U, Keyvani K, Kleinschnitz C, Scheffler B, Glas M. Regorafenib in patients with recurrent high-grade astrocytoma. J Cancer Res Clin Oncol. 2019 Apr;145(4):1037-1042. doi: 10.1007/s00432-019-02868-5. Epub 2019 Feb 28. PubMed PMID: 30820715.

DISC care

by

DISC care

https://neosurgery.com/project/spine/

Prospective multicenter cohort clinical investigation

The aim of this prospective multicenter cohort clinical investigation was to evaluate the performance and safety of a new hernia blocking system (HBS), implanted after a limited discectomy, for recurrent lumbar disc herniation prevention.

Prospective, multicenter (6 sites), cohort clinical investigation. Thirty patients with a postero-lateral disc herniation between L4-S1 and large annular defects (> 6 mm wide), who underwent a limited discectomy and were treated with a new HBS (DISC care, NEOS Surgery S.L.), were included.

Godino et al. presents details about the investigational device, its surgical technique, intraoperative parameters, and up to 6 months follow-up outcomes. The primary endpoint of the study was to assess the incidence of early symptomatic reherniation. In addition, disc height, leg and back pain (NRS 0-10), Oswestry Disability Index (ODI), quality of life (EQ-5D-5L) and device safety, were evaluated.

Clinicaltrials: gov: NCT04188236; date: 27th November 2019.

Thirty patients (43.3% female, 41.7 ± 10.9 years) were implanted with the device under evaluation in a mean of 16 ± 9.6 min. Six months after surgery, no symptomatic reherniation was detected and disc height was maintained in all patients included. All patients had a significant reduction in leg pain (> 2 points in the NRS), 92.9% improved > 15 points in the ODI and 82.6% significantly improved their quality of life (≥ 12 points in EQ VAS score). No product-related serious adverse events nor reoperations occurred.

The implantation of an HBS is a feasible and safe procedure that prevents early disc herniation recurrence in patients at high risk of reherniation 1).

Strengths of the Study Innovative Focus: The study introduces a new hernia blocking system (HBS), addressing a critical need in spine surgery—preventing recurrent lumbar disc herniation in high-risk patients. This innovation holds promise for improving post-discectomy outcomes.

Study Design: The prospective, multicenter cohort design strengthens the reliability of the findings by incorporating diverse surgical teams and patient demographics across six institutions. Such an approach minimizes potential biases from single-center studies.

Clear Methodology: The inclusion criteria are well-defined, focusing on patients with large annular defects and specific levels of herniation (L4-S1). Additionally, the assessment endpoints are clinically relevant, including reherniation rates, pain (NRS), disability (ODI), and quality of life (EQ-5D-5L).

Safety and Efficacy: The absence of symptomatic reherniation and maintenance of disc height at six months are significant outcomes, especially given the known challenges of recurrent herniation in this patient cohort. The lack of product-related serious adverse events and reoperations further supports the safety of the HBS.

Quantitative Results: Improvements in leg pain (>2 points in NRS), disability (>15 points in ODI for 92.9% of patients), and quality of life (≥12 points in EQ VAS for 82.6% of patients) are clinically significant, offering robust support for the device’s efficacy.

Weaknesses and Limitations Short Follow-Up Period: While the six-month follow-up provides early insights into the device’s safety and efficacy, recurrent disc herniations often occur beyond this timeframe. Longer-term data are essential to confirm durability and sustained benefits.

Small Sample Size: The study includes only 30 patients, limiting the generalizability of its findings. A larger cohort would enhance statistical power and the reliability of conclusions.

Lack of Control Group: The absence of a control group undergoing standard discectomy without HBS implantation makes it challenging to attribute observed benefits solely to the device. Randomized controlled trials (RCTs) are necessary to establish causation.

Subjective Outcome Measures: While NRS, ODI, and EQ-5D-5L are validated tools, they are subjective and may be influenced by patient expectations or placebo effects. Objective functional outcomes or imaging-based metrics could supplement these measures.

Potential Conflicts of Interest: The involvement of NEOS Surgery S.L. in providing the device introduces a potential bias. Transparency about funding and potential conflicts is crucial, though not explicitly addressed in the abstract.

Future Directions Extended Follow-Up: Studies with follow-ups of 2–5 years are needed to evaluate the long-term efficacy and safety of the HBS, particularly in preventing delayed reherniations and preserving disc height.

Larger, Controlled Trials: Conducting RCTs comparing HBS implantation to standard discectomy or other augmentation methods (e.g., annular closure devices) will provide more definitive evidence of its benefits.

Economic Analysis: A cost-effectiveness analysis of the HBS compared to traditional methods would be valuable, given the potential implications for widespread adoption in clinical practice.

Broader Patient Inclusion: Expanding the study to include patients with different types of disc herniations or annular defect sizes may clarify the broader applicability of the device.

Conclusion This study offers promising early evidence supporting the safety and efficacy of the HBS in preventing early recurrent lumbar disc herniation. Despite its limitations, the research sets a strong foundation for further investigation and highlights the potential of this novel device to address a significant clinical challenge. However, longer follow-ups, larger sample sizes, and randomized controlled comparisons are imperative to confirm these findings and establish the HBS as a standard of care in spinal surgery.

1)

Godino O, Fernandez-Carballal C, Català I, Moreno Á, Rimbau JM, Alvarez-Galovich L, Roldan H. A new hernia blocking system to prevent recurrent lumbar disc herniation: surgical technique, intraoperative findings and six-months post-operative outcomes. Eur Spine J. 2024 Dec 8. doi: 10.1007/s00586-024-08595-x. Epub ahead of print. PMID: 39648196.

Hubly Surgical

by

Hubly Surgical

https://hublysurgical.com/

The manual twist drill used for intracranial access represents an opportunity for potential improvement in efficiency, safety, and ease of use. A new generation of portable electrical drills with smart autostop mechanisms, such as the Hubly cranial drill (Hubly Surgical; Lisle, IL), aim to address these opportunities for improvement.

Two patients received EVDs using the portable electrical autostop drill (PEAD): A 54-year-old woman who suffered a postoperative hemorrhage and a 59-year-old woman who presented with early hydrocephalus secondary to hypertensive subarachnoid hemorrhage (SAH). Between both patients, a total of 9 and 2 access attempts were necessary to breach the inner table and visual dura. Access times in both cases, from skin incision to dural puncture, were less than 5 min. There were no apparent complications with the use of the PEAD in either case, and there was excellent placement of the EVD at the foramen of Monroe in both cases.

Oak et al. demonstrate the first successful use of a portable electrical drill with smart autostop in humans. The PEAD has potential to reduce procedure time and human error. Further development of the smart autostop drill may allow for more consistent and safer EVD placement 1).

A cadaveric study was conducted using both drills to perform several burr holes in the fronto-temporo-parietal region of the skull. An evaluation was performed on the number of dura plunges, and complete burr hole success rates were compared.

A total of 174 craniotomies using the HD and 36 burr holes using the ST perforator were performed. Despite significantly exceeding intended drill bit tolerance by multiple uses of a single-use disposable HD, autostop engaged in 100% of the 174 craniotomies and before violating dura in 99.4% of the 174 craniotomies, with the single dura penetration occurring on craniotomy no. 128 after the single-use drill bit had significantly dulled beyond its single-use tolerance. Autostop engaged before dura penetration for 100% of the 36 burr holes drilled with the ST perforator ( P = .610). All the perforations were complete using the HD after resuming drilling. An autostop mechanism in a cranial drill is not commonly available for portable bedside perforators. In the operating room, most use a mechanical method to stop the rotation after losing bone resistance. This new drill uses an electrical mechanism (smart autostop) to stop drilling, making it a single-use cranial drill with advanced features for safety and efficiency at the bedside.

There was no difference in the safety and efficacy of the new cordless electric drill with smart autostop when performing craniotomies compared with a traditional well-established electric cranial perforator with mechanical autostop on a cadaveric model 2)

1)

Oak A, Dardick J, Rusheen A, Materi J, Weingart J, Gonzalez LF, Anderson WS, Mukherjee D. First-in-human experience of a portable electrical drill with smart autostop for bedside external ventricular drain placement. J Clin Neurosci. 2024 Nov 27;131:110941. doi: 10.1016/j.jocn.2024.110941. Epub ahead of print. PMID: 39608055.
2)

Assumpcao de Monaco B, Benjamin CG, Doomi A, Taylor R, Stringfellow CE, Benveniste RJ, Jagid JR, Graciolli Cordeiro J. Safety Analysis of a New Portable Electrical Drill With a Smart Autostop Mechanism for Bedside Cranial Procedures. Oper Neurosurg (Hagerstown). 2023 Oct 1;25(4):311-314. doi: 10.1227/ons.0000000000000804. Epub 2023 Aug 4. PMID: 37543731; PMCID: PMC10468110.

pRESET stent retriever

by

pRESET stent retriever

https://www.phenox.net/fileadmin/uploads/produkt_pdf/KIF-0005C_Produktflyer_pREset_01.pdf

The pRESET stent retriever is a modern, self-expanding nitinol device designed for mechanical thrombectomy (MT) in patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO). This device is part of a growing arsenal of endovascular tools aimed at improving reperfusion outcomes and minimizing neurological damage in stroke patients.

—

#### Key Features 1. Self-Expanding Nitinol Design:

  1. Made of nitinol, a material known for its flexibility and memory shape, which aids in navigating tortuous cerebral vessels.
  2. Self-expansion ensures optimal vessel wall apposition and clot engagement.

2. Target Use:

  1. Indicated for cases of AIS caused by LVO in the anterior and posterior circulation.
  2. Designed for deployment through standard microcatheters, compatible with existing endovascular systems.

3. Recanalization Efficiency:

  1. Demonstrates high success rates in recanalizing occluded vessels, both in first-pass and subsequent attempts.
  2. Effective in combination with adjunctive therapies like aspiration.

—

#### Clinical Performance A systematic review and meta-analysis (Habibi et al., 2024) evaluated the safety and efficacy of the pRESET device: – Efficacy:

  1. First-pass success: 60% (95% CI: 52%–67%)
  2. Final recanalization success: 90% (95% CI: 83%–95%)
  3. Functional independence (mRS 0-2 at 90 days): 43% (95% CI: 34%–52%)

– Safety:

  1. Overall hemorrhagic complications: 22% (95% CI: 12%–36%)
  2. Parenchymal hemorrhage: 7% (95% CI: 4%–13%)
  3. Subarachnoid hemorrhage: 10% (95% CI: 5%–17%)
  4. Mortality: 18% (95% CI: 12%–25%)

These results suggest that the pRESET device is effective in restoring blood flow and achieving favorable functional outcomes, with complication rates comparable to other stent retrievers.

—

#### Advantages 1. High Recanalization Rates:

  1. Achieves similar or better rates compared to other market leaders like Solitaire or Trevo.

2. Versatility:

  1. Effective across a wide range of occlusion sites and clot characteristics.

3. Ease of Use:

  1. Simplified design enhances maneuverability, reducing procedural complexity.

—

#### Challenges and Considerations 1. Lack of Head-to-Head Comparisons:

  1. Most available data are observational, with few randomized controlled trials directly comparing pRESET to other stent retrievers.

2. Potential for Complications:

  1. Although within acceptable ranges, hemorrhagic complications remain a concern, underscoring the need for careful patient selection.

3. Limited Adoption:

  1. Despite promising results, broader clinical adoption may depend on further validation in diverse populations and healthcare systems.

—

#### Future Directions 1. Comparative Trials:

  1. Randomized controlled trials comparing pRESET with established devices like Solitaire or Trevo could solidify its place in the therapeutic landscape.

2. Real-World Data:

  1. Prospective registry data could provide insights into its performance across different patient demographics and clinical settings.

3. Device Innovation:

  1. Advances in stent retriever technology, such as designs that reduce clot fragmentation or improve safety in fragile vessels, could further enhance outcomes.

—

#### Conclusion The pRESET stent retriever is a promising tool for mechanical thrombectomy in LVO-related strokes, with high efficacy and an acceptable safety profile. While its recanalization and functional outcomes are impressive, additional comparative studies are needed to define its role relative to other devices. As evidence accumulates, pRESET has the potential to become a mainstay in endovascular stroke therapy.

Systematic Review and Meta-Analysis

A systematic review and meta-analysis study conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The electronic databases of PubMed, Embase, WoS, and Scopus were systematically reviewed from inception to 8 July 2024.

A total of eight studies involving 1163 patients were included. The pooled mortality rate was 18% with a 95% CI of [12%, 25%]. The rates of any hemorrhagic complication, parenchymal hemorrhage, and subarachnoid hemorrhage were 22% with a 95% CI of [12%, 36%], 7% with a 95% CI of [4%, 13%], and 10% with a 95% CI of [5%, 17%], respectively. The rate of favorable functional outcome (modified Rankin Scale 0-2) at 90 days was 43% with a 95% CI of [34%, 52%]. Successful recanalization rates were 60% with a 95% CI of [52%, 67%] after the first pass and 90% with a 95% CI of [83%, 95%] after the final pass. Rescue devices were used in 13% with a 95% CI of [7%, 24%] of cases.

The pRESET stent retriever demonstrates high recanalization rates and reasonable safety outcomes in patients undergoing mechanical thrombectomy for acute ischemic stroke due to large vessel occlusion. Further randomized trials directly comparing pRESET to other stent retrievers are warranted 1).

In a multicenter, prospective, randomized, controlled, open-label, adaptive, noninferiority trial with blinded primary end point evaluation. Between October 2019 and February 2022, multicenter participation occurred across 19 research hospitals and/or universities in the US and 5 in Germany. Patients with LVO stroke were enrolled and included up to 8 hours after symptom onset.

Interventions: Patients underwent 1:1 randomization to thrombectomy with the pRESET or Solitaire stent retriever.

Main outcomes and measures: The primary outcome was the difference in the rate of 90-day functional independence across the 2 devices, using a -12.5% noninferiority margin for the lower bound of the 1-sided 95% CI of the difference between pRESET and Solitaire retrievers.

Results: Of 340 randomized patients, 170 (50.0%) were female, and the median (IQR) age was 73.0 (64.0-82.0) years. The study procedure was completed in 322 of the 340 randomized patients. The primary end point of 90-day functional independence was achieved by 95 patients (54.9%; 95% CI, 48.7-61.1) in the pRESET group and in 96 (57.5%; 95% CI, 51.2-63.8) in the Solitaire group (absolute difference, -2.57%; 95% CI, -11.42 to 6.28). As the lower bound of the 95% CI was greater than -12.5%, the pRESET retriever was deemed noninferior to the Solitaire retriever. The noninferiority of pRESET over Solitaire was also observed in the secondary clinical end point (90-day shift in modified Rankin Scale score) and in both angiographic end points (Expanded Treatment in Cerebral Infarction [eTICI] score of 2b50 or greater within 3 passes: 146 of 173 [84.4%] vs 149 of 167 [89.2%]; absolute difference, -4.83%; 95% CI, -10.84 to 1.19; eTICI of 2c or greater following the first pass: 76 of 173 [43.7%] vs 74 of 167 [44.3%]; absolute difference, -0.63%; 95% CI, -9.48 to 8.21). Symptomatic intracranial hemorrhage occurred in 0 patients in the pRESET group and 2 (1.2%) in the Solitaire group. Mortality occurred in 25 (14.5%) in the pRESET group and in 24 (14.4%) in the Solitaire group at 90 days. Findings of the per-protocol and as-treated analyses were in concordance with findings of the intention-to-treat analysis.

In this study, among patients with Large Vessel Occlusion (LVO) stroke, thrombectomy with the pRESET stent retriever was noninferior to thrombectomy with the Solitaire stent retriever. Findings suggest that pRESET offers a safe and effective option for flow restoration and disability reduction in patients with LVO stroke 2).

1)

Habibi MA, Ahmadvand MH, Delbari P, Sabet S, Zare AH, Mirjani MS, Boskabadi AR, Kolur ZA, Bozorgi M. The safety and efficacy of pRESET stent retriever for treatment of thrombo-embolic stroke; a systematic review and meta-analysis. Neuroradiol J. 2024 Nov 27:19714009241303083. doi: 10.1177/19714009241303083. Epub ahead of print. PMID: 39604086.
2)

Nogueira RG, Lobsien D, Klisch J, Pielenz D, Lobsien E, Sauvageau E, Aghaebrahim N, Möhlenbruch M, Vollherbst D, Ulfert C, Bozorgchami H, Clark W, Priest R, Samaniego EA, Ortega-Gutierrez S, Ghannam M, Lopes D, Billingsley J, Keigher K, Haussen DC, Al-Bayati AR, Siddiqui A, Levy E, Chen M, Munich S, Schramm P, Boppel T, Narayanan S, Gross BA, Roth C, Boeckh-Behrens T, Hassan A, Fifi J, Budzik RF, Tarpley J, Starke RM, Raz E, Brogan G, Liebeskind DS, Hanel RA. Thrombectomy With the pRESET vs Solitaire Stent Retrievers as First-Line Large Vessel Occlusion Stroke Treatment: A Randomized Clinical Trial. JAMA Neurol. 2024 Jan 2. doi: 10.1001/jamaneurol.2023.5010. Epub ahead of print. PMID: 38165690.

Proton magnetic resonance spectroscopic imaging in glioblastoma recurrence diagnosis

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Proton magnetic resonance spectroscopic imaging in glioblastoma recurrence diagnosis

Proton magnetic resonance spectroscopic imaging (MRSI) is a non-invasive imaging technique that assesses the metabolic profile of brain tissues, offering valuable insights into the diagnosis and monitoring of glioblastoma recurrence. By measuring concentrations of metabolites such as choline (Cho), N-acetylaspartate (NAA), and creatine (Cr), MRSI aids in distinguishing between tumor recurrence and treatment-induced changes like radiation necrosis.

Key Metabolites in MRSI

– Choline (Cho): Elevated levels indicate increased cellular membrane turnover, commonly associated with tumor proliferation.

– N-acetylaspartate (NAA): Reduced levels suggest neuronal loss or dysfunction, often observed in tumor regions.

– Creatine (Cr): Serves as a reference metabolite for energy metabolism, typically stable across different tissues.

Chemical Shift Imaging: Provides information about the metabolic composition of tissues. Elevated levels of choline and decreased N-acetylaspartate (NAA) may indicate recurrent tumors.

Choline to N-Acetylaspartate Ratio in Glioblastoma Recurrence Diagnosis

Choline to N-Acetylaspartate Ratio in Glioblastoma Recurrence Diagnosis

Clinical Applications

1. Differentiating Tumor Recurrence from Radiation Injury: MRSI can help distinguish recurrent GBM from radiation-induced changes. Recurrent tumors often exhibit increased Cho/Cr and Cho/NAA ratios, whereas radiation injuries may show different metabolic patterns.

2. Guiding Radiotherapy Planning: Incorporating MRSI into radiotherapy planning allows for targeted dose escalation to metabolically active tumor regions, potentially improving local control and patient outcomes.

3. Monitoring Treatment Response: MRSI enables the assessment of metabolic changes over time, providing insights into treatment efficacy and early detection of recurrence.

Advantages of MRSI

– Non-Invasive: Offers a non-invasive method to assess tumor metabolism without the need for biopsy.

– Metabolic Insights: Provides detailed information on tumor biochemistry, complementing anatomical imaging.

– Early Detection: Facilitates the early identification of tumor recurrence before structural changes become apparent.

Limitations

– Technical Complexity: Requires specialized equipment and expertise for acquisition and interpretation.

– Spatial Resolution: May have lower spatial resolution compared to conventional MRI, potentially limiting the detection of small lesions.

In summary, proton MRSI is a valuable tool in the management of glioblastoma, enhancing the ability to differentiate between tumor recurrence and treatment effects, guiding therapy, and monitoring disease progression.

Systematic Reviews

Of 7350 records for MR spectroscopy, GBM, glioma, recurrence, diffusion, perfusion, pseudoprogression, radiomics, and advanced imaging, they screened 574 papers. A total of 228 were eligible, and analyzed 72 of them, in order to establish the role of each imaging modality and the usefulness and limitations of radiomics analysis 1).

Prospective diagnostic accuracy studies

A prospective single-institutional study aims to determine and validate thresholds for the main metabolite concentrations obtained by MR spectroscopy (MRS) and the values of the apparent diffusion coefficient (ADC) to enable distinguishing tumor recurrence from pseudoprogression. Thirty-nine patients after the standard treatment of a glioblastoma underwent advanced imaging by MRS and ADC at the time of suspected recurrence – the median time to progression was 6.7 months. The highest significant sensitivity and specificity to call the glioblastoma recurrence was observed for the total choline (tCho) to total N-acetyl aspartate (tNAA) concentration ratio with the threshold ≥ 1.3 (sensitivity 100.0% and specificity 94.7%). The ADC mean value higher than 1313 × 10(- 6) mm(2)/s was associated with pseudoprogression (sensitivity 98.3%, specificity 100.0%). The combination of MRS focused on the tCho/tNAA concentration ratio and the ADCmean value represents imaging methods applicable to early non-invasive differentiation between a glioblastoma recurrence and a pseudoprogression. However, the institutional definition and validation of thresholds for differential diagnostics are needed for the elimination of setup errors before the implementation of these multimodal imaging techniques into clinical practice, as well as into clinical trials 2).

Retrospective cohort studies

A study of Lu et al. aimed to evaluate the predictive value of metabolic parameters in preoperative non-enhancing peritumoral regions (NEPTRs) for glioblastoma recurrence, using multivoxel hydrogen proton magnetic resonance spectroscopy (1H-MRS). Clinical and imaging data from patients with recurrent glioblastoma were analyzed. Through co-registration of preoperative and post-recurrence MRI, they identified future tumor recurrence regions (FTRRs) and future non-tumor recurrence regions (FNTRRs) within the NEPTRs. Metabolic parameters were recorded separately for each region. Cox regression analysis was applied to assess the association between metabolic parameters and glioblastoma recurrence. Compared to FNTRRs, FTRRs exhibited a higher Cho/Cr ratio, higher Cho/NAA ratio, and lower NAA/Cr ratio. Both Cho/NAA and Cho/Cr ratios were recognized as risk factors in univariate and multivariate analyses (P < 0.05). The Cox regression model indicated that Cho/NAA > 1.99 and Cho/Cr > 1.73 are independent risk factors for early glioblastoma recurrence. Based on these cut-off values, patients were stratified into low-risk and high-risk groups, with a statistically significant difference in recurrence rates between the two groups (P < 0.01). The Cho/NAA and Cho/Cr ratios in NEPTRs are independent predictors of future glioblastoma recurrence. Specifically, Cho/NAA > 1.99 and/or Cho/Cr > 1.73 in NEPTRs may indicate a higher risk of early postoperative recurrence at these regions 3).

This study demonstrates that metabolic ratios (Cho/NAA and Cho/Cr) in NEPTRs are independent predictors of glioblastoma recurrence and proposes clinically relevant cut-off values for risk stratification. While the findings are promising, limitations such as small sample size, lack of external validation, and potential confounding factors highlight the need for further research. The integration of metabolic and molecular data, along with validation in larger cohorts, could significantly enhance the clinical utility of these predictors.

1)

Sidibe I, Tensaouti F, Roques M, Cohen-Jonathan-Moyal E, Laprie A. Pseudoprogression in Glioblastoma: Role of Metabolic and Functional MRI-Systematic Review. Biomedicines. 2022 Jan 26;10(2):285. doi: 10.3390/biomedicines10020285. PMID: 35203493; PMCID: PMC8869397.
2)

Kazda T, Bulik M, Pospisil P, Lakomy R, Smrcka M, Slampa P, Jancalek R. Advanced MRI increases the diagnostic accuracy of recurrent glioblastoma: Single institution thresholds and validation of MR spectroscopy and diffusion weighted MR imaging. Neuroimage Clin. 2016 Feb 26;11:316-321. doi: 10.1016/j.nicl.2016.02.016. PMID: 27298760; PMCID: PMC4893011.
3)

Lu W, Feng J, Zou Y, Liu Y, Gao P, Zhao Y, Wu X, Ma H. 1H-MRS parameters in non-enhancing peritumoral regions can predict the recurrence of glioblastoma. Sci Rep. 2024 Nov 26;14(1):29258. doi: 10.1038/s41598-024-80610-z. PMID: 39587278.

Bilingualism

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Bilingualism

Bilingualism refers to the ability to use two languages proficiently. A bilingual person can speak, understand, read, and write in two languages with varying degrees of fluency. Bilingualism is not a uniform concept; it can manifest in different ways depending on factors such as language proficiency, context, and the timing of learning.

Here are key points about bilingualism:

### Types of Bilingualism: 1. Simultaneous Bilingualism: This occurs when a person learns two languages from birth or early childhood, typically in a bilingual environment. This is common in families where parents speak different languages.

2. Sequential (or Successive) Bilingualism: This happens when a person learns a second language after already being proficient in a first language, often in childhood or adulthood. For example, a child might learn their native language at home and then acquire a second language at school.

3. Balanced Bilingualism: This refers to a situation where a person has nearly equal proficiency in both languages. While rare, this is the ideal for some bilinguals.

4. Dominant Bilingualism: In this case, one language is stronger or more frequently used than the other. For instance, someone who speaks both Spanish and English but uses English more often may be considered dominant in English.

5. Passive Bilingualism: A person understands a second language but is not able to speak or use it actively.

### Cognitive and Neurological Aspects: – Cognitive Benefits: Bilingualism has been linked to cognitive advantages, such as better executive function (e.g., problem-solving, multitasking, and memory) and delayed onset of age-related cognitive decline, including Alzheimer’s disease.

– Language Switching: Bilinguals can switch between languages depending on the context, a process known as code-switching. This flexibility relies on the brain’s ability to manage and control both languages.

– Brain Activation: Studies have shown that bilinguals often have denser gray matter in areas of the brain related to language processing. The brain of a bilingual person is particularly adept at managing the interference from competing languages, which enhances cognitive flexibility.

### Social and Cultural Aspects: – Cultural Identity: Bilingualism can be tied to cultural identity. For many bilinguals, each language may represent a different cultural aspect of their life, and they may switch languages depending on the social or cultural context.

– Communication: Bilinguals have the advantage of communicating with a wider range of people across different linguistic communities, which can be particularly useful in multilingual regions or professional settings.

### Challenges of Bilingualism: – Language Interference: Sometimes, one language can interfere with the other, causing errors such as mixing vocabulary, grammar, or pronunciation (e.g., “Spanglish” or “Franglais”). This is especially common in simultaneous bilinguals.

– Language Maintenance: Bilinguals may struggle to maintain proficiency in both languages, especially if one language is used more frequently than the other. This can lead to language attrition, where one language becomes weaker over time.

– Social Perceptions: In some regions, bilingual individuals may face social stigma or discrimination, especially if one of their languages is viewed as less prestigious or less widely spoken.

### Conclusion: Bilingualism is a dynamic and complex phenomenon that involves not just language proficiency but also cognitive, social, and cultural factors. It provides numerous benefits, both personally and professionally, but can also come with challenges, particularly in balancing both languages and navigating social perceptions.

The utility of intraoperative mapping in multilingual patients with brain tumors in speech-eloquent locations is evidenced by reports of heterogeneity of the location and number of language areas. Furthermore, preserving the ability to switch between languages is crucial for multilingual patients’ communication and quality of life. Barua et al. report the first case of intraoperative bilingual and language-switching testing in a child undergoing awake craniotomy for a tumor within the left superior temporal gyrus using a novel test paradigm. Stimulation of the posterior superior temporal gyrus resulted in anomia when switching from Polish to English, in the absence of any stimulation effect on switching from English to Polish or object naming in each language 1)

The article *“Bilingual awake craniotomy with English and Polish language mapping in a 15-year-old patient provides evidence for the role of the left superior temporal gyrus in language switching”* (Acta Neurochir, 2024 Nov 13;166(1):452) presents an intriguing study on the role of the left superior temporal gyrus (STG) in bilingual language switching. The authors—Neil U Barua, Hajira Mumtaz, Sonia Mariotti, Molly Cree, Agdaliya Mikhalkova, Greg A Fellows, and Anna E Piasecki—explore a novel approach to intraoperative language mapping in a young multilingual patient undergoing awake craniotomy for a tumor in the left superior temporal gyrus. This report highlights the utility of mapping bilingual language areas and provides significant insights into the complex brain regions involved in switching between languages.

### Strengths:

1. Novel Methodology: The use of a bilingual awake craniotomy in a 15-year-old patient is groundbreaking, as it is the first report of such an approach for mapping language switching between English and Polish. This methodology can offer a deeper understanding of the neural mechanisms underlying multilingual language processing, especially in children, who may exhibit unique brain adaptations.

2. Clinical Relevance: The study is highly relevant for clinical neuropsychology, particularly for multilingual patients with brain tumors in speech-eloquent regions. By demonstrating the distinct brain activity involved in language switching, the findings may guide surgeons in preserving both language abilities during resection of tumors in these areas, ultimately improving postoperative quality of life for patients.

3. Specific Findings: The case highlights the critical role of the posterior superior temporal gyrus (STG) in switching between languages. The stimulation-induced anomia specifically when switching from Polish to English—without affecting the ability to name objects in each language individually—emphasizes the specialized role of the STG in language switching rather than simple language production. This nuanced finding adds to the existing body of literature and suggests the need for further studies to map out language-specific regions more thoroughly.

### Weaknesses:

1. Generalizability: As a single case report, the findings should be viewed with caution. It is difficult to generalize the results to other bilingual individuals, particularly in different age groups, with different language pairs, or those with other neurological conditions. The authors themselves acknowledge that further studies with larger sample sizes are needed to confirm the results and expand the findings to a wider population.

2. Language Pair Considerations: The study examines only two languages—English and Polish. While this is an important step, the findings are limited to this particular language pair. Different language pairs may activate different regions of the brain due to variations in phonology, syntax, and other language-specific features. It would be interesting to see if similar results are observed in individuals who speak languages that are typologically distant, such as English and Mandarin, or among individuals with more complex multilingual profiles.

3. Neuroplasticity: The study does not address the potential influence of neuroplasticity on language functions in multilingual individuals. Children, in particular, may demonstrate different neural organization compared to adults, and the influence of age, experience, and neural reorganization in response to the tumor could affect the outcome. This aspect would benefit from further exploration.

### Suggestions for Future Research:

– Larger Cohort Studies: It would be valuable to conduct similar research on a larger cohort of multilingual patients to identify whether the observed effects are consistent across different language pairs and in different populations (e.g., adults vs. children).

– Long-Term Follow-Up: A longitudinal follow-up of postoperative language outcomes would offer insight into the long-term impact of preserving specific areas of the STG and other brain regions involved in language switching.

– Comparative Language Pairs: Future studies could explore different language pairs or more complex multilingual cases, which might reveal additional findings or patterns in language representation and switching.

### Conclusion:

This report provides compelling evidence for the involvement of the left superior temporal gyrus in language switching, contributing valuable knowledge to the field of multilingual neuropsychology. Although the findings are based on a single case, the study demonstrates the importance of intraoperative language mapping in bilingual patients undergoing neurosurgery. The findings hold promise for improving surgical outcomes for multilingual individuals, offering a more nuanced understanding of how the brain manages multiple languages. Nonetheless, further research is needed to validate these results and extend the implications to broader clinical practice.

Neural basis of language switching and the cognitive models of bilingualism remain controversial.

Sierpowska et al. explored the functional neuroanatomy of language switching implementing a new multimodal protocol assessing neuropsychological, functional magnetic resonance, and intraoperative Electrostimulation mapping results. A prospective series of 9 Spanish-Catalan bilingual candidates for awake brain surgery underwent a specific language-switching paradigm implemented both before and after surgery, throughout the Electrostimulation procedure, and during functional magnetic resonance both pre-and postoperatively. All patients were harboring left-hemispheric intrinsic brain lesions and were presenting functional language-related activations within the affected hemisphere. Language functional maps were reconstructed based on the intraoperative Electrostimulation results and compared to the functional magnetic resonance findings. Single language-naming sites (Spanish and Catalan), as well as language-switching naming sites were detected by Electrostimulation mapping in 8 patients (in one patient only Spanish-related sites were detected). Single naming points outnumbered the switching points and did not overlap with each other. Within the frontal lobe, the single language naming sites were found significantly more frequently within the inferior frontal gyrus as compared to the middle frontal gyrus [X2 (1) = 20.3, p < .001]. Contrarily, switching naming sites were distributed across the middle frontal gyrus significantly more often than within the inferior frontal gyrus [X2 (1) = 4.1, p = .043]. Notably, there was not always an overlap between functional magnetic resonance and Electrostimulation mapping findings. After surgery, patients did not report involuntary language switching and their neuropsychological scores did not differ significantly from the pre-surgical examinations. Our results suggest a functional division of the frontal cortex between naming and language switching functions, supporting that non-language specific cognitive control prefrontal regions (middle frontal gyrus) are essential to maintain effective communication together with the classical language-related sites (inferior frontal gyrus) 2).

1)

Barua NU, Mumtaz H, Mariotti S, Cree M, Mikhalkova A, Fellows GA, Piasecki AE. Bilingual awake craniotomy with English and Polish language mapping in a 15-year-old patient provides evidence for the role of the left superior temporal gyrus in language switching. Acta Neurochir (Wien). 2024 Nov 13;166(1):452. doi: 10.1007/s00701-024-06358-7. PMID: 39535621.
2)

Sierpowska J, Fernandez-Coello A, Gomez-Andres A, Camins À, Castañer S, Juncadella M, Gabarrós A, Rodríguez-Fornells A. Involvement of the middle frontal gyrus in language switching as revealed by Electrostimulation mapping and functional magnetic resonance imaging in bilingual brain tumor patients. Cortex. 2017 Nov 14;99:78-92. doi: 10.1016/j.cortex.2017.10.017. [Epub ahead of print] PubMed PMID: 29197227.