====== Dystonia case series ====== ===== 2022 ===== retrospectively reviewed all pediatric patients (less than 18 years of age) with acquired/heredodegenerative generalized dystonia who underwent bilateral simultaneous pallidotomy at their center between January 2014 and January 2021. Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) scores before and after surgery were recorded. Complications arising after the procedure were recorded as well. Results: Ten patients (8 male and 2 female) with a mean (range) age of 11.1 (5-17) years were included in this study. The mean duration between disease onset and surgical intervention was 3.9 years. Two patients presented in status dystonicus. The mean ± SD (range) preoperative BFMDRS score of the patients without status dystonicus (n = 8) was 80 ± 18.9 (59.5-108). The mean ± SD BFMDRS score at the time of discharge from the hospital after surgery was 58.8 ± 37.9. Three patients had more than 20% change in BFMDRS score at the time of discharge from the hospital. The mean improvement was 25.5% at the end of 1 year. Of 5 surviving patients in the non-status dystonic group, 3 patients had more than 40% change in BFMDRS score while the other 2 patients developed recurrence at the last follow-up (4.5 years). Status dystonicus abated after bilateral pallidotomy in both patients. Permanent bulbar complications were seen in 2 patients. Conclusions: Bilateral pallidotomy may result in clinically significant improvement in children with acquired/heredodegenerative generalized dystonia, although the benefits should be closely weighed against the risk of irreversible bulbar dysfunction. It is a viable option for children in resource-limited settings ((Garg K, Singh M, Samala R, Rajan R, Gulati S, Goyal V. Bilateral pallidotomy for acquired or heredodegenerative generalized dystonia in children. Neurosurg Focus. 2022 Oct;53(4):E12. doi: 10.3171/2022.7.FOCUS22332. PMID: 36183185.)). ===== 2021 ===== Sixteen patients with [[idiopathic dystonia]] (39.9 ± 13 years old, n = 14 generalized) with [[DBS]] of the [[globus pallidus internus]] underwent a battery of quantitative sensory testing and assessment using a pain top-down modulation system (conditioned pain modulation, CPM). Results for the more and less dystonic body regions were compared in on and off stimulation. The patients' results were compared to age- and sex-matched healthy volunteers (HV). Descending pain modulation CPM responses in dystonic patients (on-DBS, 11.8 ± 40.7; off-DBS, 1.8 ± 22.1) was abnormally low (defective) compared to HV (-15.6 ± 23.5, respectively p = .006 and p = .042). Cold pain threshold and cold hyperalgesias were 54.8% and 95.7% higher in dystonic patients compared to HV. On-DBS CPM correlated with higher Burke-Fahn-Marsden disability score (r = 0.598; p = .014). While sensory and pain thresholds were not affected by DBS on/off condition, pain modulation was abnormal in dystonic patients and tended to be aggravated by DBS. The analgesic effects after DBS do not seem to depend on short-duration changes in cutaneous sensory thresholds in dystonic patients and may be related to changes in the central processing of [[nociception]] ((Listik C, Cury RG, da Silva VA, Casagrande SCB, Listik E, Link N, Galhardoni R, Barbosa ER, Teixeira MJ, Ciampi de Andrade D. Abnormal sensory thresholds of dystonic patients are not affected by deep brain stimulation. Eur J Pain. 2021 Mar 19. doi: 10.1002/ejp.1757. Epub ahead of print. PMID: 33740316.)). ---- Thirty-nine patients with dystonia treated with bilateral [[Pallidal Deep Brain Stimulation]] at 2 Swedish DBS centers from 2005 to 2015 were included. Different pulse widths (PW) paradigms were used at the 2 centers, 60-90 µs (short PWs) and 450 µs (long PW), respectively. The frequency of IPG replacements, pulse effective voltage (PEV), IPG model, pre-/postoperative imaging, and clinical outcome based on the clinical global impression (CGI) scale were collected from the medical charts and compared between the 2 groups. Results: The average IPG longevity was extended for the short PWs (1,129 ± 50 days) compared to the long PW (925 ± 32 days; χ2 = 12.31, p = 0.0005, log-rank test). IPG longevity correlated inversely with PEV (Pearson's r = -0.667, p < 0.0001). IPG longevities did not differ between Kinetra® and Activa® PC in the short (p = 0.319) or long PW group (p = 0.858). Electrode distances to the central sensorimotor region of the GPi did not differ between the short or long PW groups (p = 0.595). Pre- and postoperative CGI did not differ between groups. Short PWs were associated with decreased energy consumption and increased IPG longevity. These effects were not dependent on the IPG model or the anatomic location of the electrodes. PWs did not correlate with symptom severities or clinical outcomes. The results suggest that the use of short PWs might be more energy efficient and could therefore be preferred initially when programming patients with GPi DBS for dystonia ((Ågren R, Bartek J Jr, Johansson A, Blomstedt P, Fytagoridis A. Pulse Width and Implantable Pulse Generator Longevity in Pallidal Deep Brain Stimulation for Dystonia: A Population-Based Comparative Effectiveness Study [published online ahead of print, 2020 Jul 15]. Stereotact Funct Neurosurg. 2020;1-6. doi:10.1159/000508794)). ---- [[Lead]] [[placement]] for [[deep brain stimulation]] (DBS) using [[Intraoperative magnetic resonance imaging]] ([[iMRI]]) relies solely on real-time [[intraoperative]] [[neuroimaging]] to guide [[electrode]] [[placement]], without [[microelectrode recording]] (MER) or Electrostimulation. There is limited information, however, on outcomes after iMRI-guided DBS for [[dystonia]]. Sharma et al. evaluated clinical outcomes and targeting accuracy in patients with dystonia who underwent lead placement using an iMRI targeting platform. Patients with dystonia undergoing iMRI-guided lead placement in the globus pallidus pars internus (GPi) were identified. Patients with a prior ablative or MER-guided procedure were excluded from clinical outcomes analysis. Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) scores and Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) scores were assessed preoperatively and at 6 and 12 months postoperatively. Other measures analyzed include lead accuracy, complications/adverse events, and stimulation parameters. A total of 60 leads were implanted in 30 patients. Stereotactic lead accuracy in the axial plane was 0.93 ± 0.12 mm from the intended target. Nineteen patients (idiopathic focal, n = 7; idiopathic segmental, n = 5; DYT1, n = 1; tardive, n = 2; other secondary, n = 4) were included in clinical outcomes analysis. The mean improvement in BFMDRS score was 51.9% ± 9.7% at 6 months and 63.4% ± 8.0% at 1 year. TWSTRS scores in patients with predominant cervical dystonia (n = 13) improved by 53.3% ± 10.5% at 6 months and 67.6% ± 9.0% at 1 year. Serious complications occurred in 6 patients (20%), involving 8 of 60 implanted leads (13.3%). The rate of serious complications across all patients undergoing iMRI-guided DBS at the authors' institution was further reviewed, including an additional 53 patients undergoing GPi-DBS for Parkinson's disease. In this expanded cohort, serious complications occurred in 11 patients (13.3%) involving 15 leads (10.1%). Intraoperative MRI-guided lead placement in patients with dystonia showed improvement in clinical outcomes comparable to previously reported results using awake MER-guided lead placement. The accuracy of lead placement was high, and the procedure was well tolerated in the majority of patients. However, a number of patients experienced serious adverse events that were attributable to the introduction of a novel technique into a busy neurosurgical practice, and which led to the revision of protocols, product inserts, and on-site training ((Sharma VD, Bezchlibnyk YB, Isbaine F, Naik KB, Cheng J, Gale JT, Miocinovic S, Buetefisch C, Factor SA, Willie JT, Boulis NM, Wichmann T, DeLong MR, Gross RE. Clinical outcomes of pallidal deep brain stimulation for dystonia implanted using intraoperative MRI. J Neurosurg. 2019 Oct 11:1-13. doi: 10.3171/2019.6.JNS19548. [Epub ahead of print] PubMed PMID: 31604331. )). ---- Schrader et al retrospectively screened the database of patients with dystonia who underwent DBS. Patients with focal, segmental, or [[generalized dystonia]] of primary or tardive origin and no gait disorder due to lower limb dystonia before DBS, bilateral pallidal stimulation, and a follow-up for more than 6 months were included. Reports of adverse events were analyzed, and gait abnormalities were scored by comparing preoperative and postoperative video recordings using Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) items 3.10 (gait) and 3.11 (FOG). To assess the role of [[GPi]]-DBS in gait abnormalities, DBS was paused for 24 hours. Gait and FOG were assessed 30 minutes, 2 hours, and 24 hours after restarting DBS. Finally, a standardized adjustment algorithm was performed trying to eliminate the gait disorder. Of a collective of 71 patients with dystonia, 6 presented with a new gait disorder (8.5%; 2 men, 4 women, mean age 61.3 years [48-69 years], 2 craniocervical, 1 DYT-1 segmental, 1 truncal, 2 tardive dystonia). GPi-DBS improved Burke-Fahn-Marsden Dystonia Rating Scale motor score by 54% and disability score by 52%. MDS-UPDRS item 3.10 worsened from 0.5 (±0.8) to 2.0 (±0.9) and item 3.11 from 0 to 2.5 (±0.5). The gait disorder displayed shuffling steps and difficulties with gait initiation and turning. Increasing voltages improved dystonia but triggered FOG, sometimes worsening over a period of a few hours. It vanished within minutes after ceasing DBS. Electrode misplacement was ruled out. In all but one patient, no optimal configuration was found despite extensive testing of settings (monopolar, bipolar, pulse width 60-210 μs, frequency 60-180 Hz). Nevertheless, a compromise between optimal stimulation for dystonia and eliciting FOG was achieved in each case. A hypokinetic gait disorder with FOG can be a complication of GPi-DBS ((Schrader C, Capelle HH, Kinfe TM, Blahak C, Bäzner H, Lütjens G, Dressler D, Krauss JK. GPi-DBS may induce a hypokinetic gait disorder with freezing of gait in patients with dystonia. Neurology. 2011 Aug 2;77(5):483-8. doi: 10.1212/WNL.0b013e318227b19e. Epub 2011 Jul 20. PubMed PMID: 21775741. )).