Diffuse axonal injury case series
Cicuendez et al. attempted to determine whether any Magnetic resonance imaging findings of traumatic axonal injury (TAI) could be related to prognosis in 264 patients with severe traumatic brain injury. They performed an ordinal logistic regression, adjusted for the prognostic factors according to the International Mission for Prognosis and Analysis of Clinical Trial in TBI studies, adding each MR feature related to prognosis one at a time. A new prognostic model was described by adding these MR features to the classic prognostic factors. The model was externally validated in a prospective series. Harrel's c-statistic and ordinal c-index (ORC) was calculated to measure its predictive accuracy.
They found 178 patients with TAI lesions. Lesions in the basal ganglia/thalamus, corpus callosum (CC) and brain stem were associated with poor outcome (P < 0.01). The highest OR was for TAI lesions in the splenium (OR: 2.6) and brain stem dorsal lesions (OR: 3.1). They only found significant differences in outcome between hemorrhagic and non-hemorrhagic TAI lesions in the subgroup of patients with white matter and basal ganglia/thalamus lesions (P = 0.01). They obtained a superior discriminatory capacity by adding these MR findings to the previous prognostic model (Harrel's c-statistic 0.72 and ORC 0.7) in a prospective series of 93 patients.
The prognostic model including MR findings maintained a superior discriminatory capacity than that obtained for the model with the classic prognostic factors alone 1).
Twenty-four patients from Sao Paulo Brazil.with moderate or severe DAI were evaluated at 2, 6 and 12 months post-injury. Microhaemorrhage load (MHL) was evaluated at 3 months, and brain volumetry was evaluated at 3, 6 and 12 months. The trail making test (TMT) was used to evaluate executive function (EF), and the Hopkins verbal learning test (HVLT) was used to evaluate verbal episodic memory (EVM) at 6 and 12 months.
There were significant white matter volume (WMV), subcortical grey matter volume and total brain volume (TBV) reductions during the study period (p < 0.05). MHL was correlated only with WMV reduction. EF and EVM were not correlated with MHL but were, in part, correlated with WMV and TBV reductions.
The findings suggest that MHL may be a predictor of WMV reduction but cannot predict EF or EVM in DAI. Brain atrophy progresses over time, but patients showed better EF and EVM in some of the tests, which could be due to neuroplasticity 2).
2017
Cicuendez et al. retrospectively analyzed 264 Traumatic brain injury (TBI) patients to whom a MR had been performed in the first 60 days after trauma. All clinical variables related to prognosis were registered, as well as the data from the initial computed tomography. The MR imaging protocol consisted of a 3-plane localizer sequence T1-weighted and T2-weighted fast spin-echo, FLAIR and gradient-echo images (GRET2*). Traumatic axonal injury (TAI) lesions were classified according to Gentry and Firsching classifications. They calculated weighted kappa coefficients and the area under the ROC curve for each MR sequence. A multivariable analyses was performed to correlate MR findings in each sequence with the final outcome of the patients.
TAI lesions were adequately visualized on T2, FLAIR and GRET2* sequences in more than 80% of the studies. Subcortical TAI lesions were well on FLAIR and GRET2* sequences visualized hemorrhagic TAI lesions. We saw that these MR sequences had a high inter-rater agreement for TAI diagnosis (0.8). T2 sequence presented the highest value on ROC curve in Gentry (0.68, 95%CI: 0.61-0.76, p<0.001, Nagerlkerke-R2 0.26) and Firsching classifications (0.64, 95%CI 0.57-0.72, p<0.001, Nagerlkerke-R2 0.19), followed by FLAIR and GRET2* sequences. Both classifications determined by each of these sequences were associated with poor outcome after performing a multivariable analyses adjusted for prognostic factors (p<0.02).
They recommend to perform conventional MR study in subacute phase including T2, FLAIR and GRET2* sequences for visualize TAI lesions. These MR findings added prognostic information in TBI patients 3).
Cell therapy in neurological disability after traumatic brain injury (TBI) is in its initial clinical stage.
Vaquero et al., describe the preliminary clinical experience with three patients with diffuse axonal injury (DAI) who were treated with intrathecal administration of autologous mesenchymal stem cells (MSCs).
Three patients with established neurological sequelae due to DAI received intrathecally autologous MSCs. The total number of MSCs administered was 60 × 106 (one patient), 100 × 106 (one patient) and 300 × 106 (one patient).
All three patients showed improvement after cell therapy, and subsequent studies with 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) showed a diffuse and progressive increase in brain glucose metabolism.
The present results suggest benefit of intrathecal administration of MSCs in patients with DAI, as well as a relationship between this type of treatment and increase in brain glucose metabolism. These preliminary findings raise the question of convenience of assessing the potential benefit of intrathecal administration of MSCs for brain diseases in which a decrease in glucose metabolism represents a crucial pathophysiological finding, such as Alzheimer's disease (AD) and other dementias 4).
Data were collected retrospectively from a prospectively created database registry in the section of Trauma Surgery at Hamad General Hospital between January 2008 and July 2012. All patients presented with head trauma and TSAH were included. Patient data included age, gender, nationality, mechanism of injury, injury severity score (ISS), types of head injuries, and associated injuries. Ventilator days, intensive care unit length of stay, pneumonia, and mortality were also studied.
A total of 1665 patients with TBI were identified, of them 403 had TSAH with a mean age of 35 ± 15 years. Of them 93% were male patients and 86% were expatriates. MVC (53%) and FFH (35%) were the major mechanisms of injury. The overall mean ISS and head abbreviated injury score were 19 ± 10.6 and 3.4 ± 0.96, respectively. Patients in MVC group sustained severe TSAH, had significantly greater head abbreviated injury score (3.5 ± 0.9 vs. 3.2 ± 0.9; P = 0.009) and ISS (21.6 ± 10.6 vs. 15.9 ± 9.5; P = 0.001), and lower scene Glasgow coma scale (10.8 ± 4.8 vs. 13.2 ± 3.4; P = 0.001) compared with the FFH group. In addition, the MVC group sustained more intraventricular hemorrhage (4.7 vs. 0.7; P = 0.001) and diffuse axonal injury (4.2 vs. 2.9; P = 0.001). In contrast, extradural hemorrhage (14.3% vs. 11.6%; P = 0.008) was higher in the FFH group. Lower extremities (14% vs. 4.3%; P = 0.004) injury was mainly associated with the MVC group. The overall mortality was 19 % among patients with TSAH. The mortality rate was higher in the MVC group when compared with the FFH group (24% vs. 10%; P = 0.001). In both groups, ISS and Glasgow coma scale at the scene were independent predictors of mortality.
Patients with TSAH have a higher mortality rate. In this population, MVCs are associated with a 3-fold increased risk of mortality. Therefore, prevention of MVC and fall can reduce the incidence and severity of TBI in Qatar 5).
A retrospective study over a 4-year period (2004-2007) of 124 patients admitted for head trauma. Demographic, clinical, biological, and radiologic findings were recorded at admission and during intensive care unit stay.
Mean age (±standard deviation) was 28 years±15.8 years. Cranial computed tomography scan was sufficient enough to diagnose DAI in 31 patients. Magnetic resonance imaging was performed in 105 patients with a delay of 7.7 days±8.6 days. Most patients were classified as stage II (49.5%) or stage III (44.8%) according to Gentry's classification. In a multivariate analysis, factors associated with higher mortality were dysautonomia (p=0.018; odds ratio [OR]=4.17), hyperglycemia≥8 mmol/L (p=0.001; OR=3.84) on intensive care unit admission, and subdural hematoma (p=0.031; OR=3.99), whereas factors associated to poor outcome according to Glasgow Outcome Scale score were Glasgow Coma Scale score<8 (p=0.032, OR=3.55), secondary systemic injuries score≥3 (p=0.034, OR=2.83), hyperglycemia≥8 mmol/L (p=0.002, OR=5.55), and DAI count≥6 (p=0.035, OR=3.33). In patients with pure DAI, the absence of consciousness recovery was the unique independent factor of mortality (p<0.001, OR=116.4), whereas only transfusion need was an independent factor of poor outcome (p=0.017, OR=4.44).
Dysautonomia, hyperglycemia, and subdural hematoma are the main factors associated to higher mortality when DAIs are diagnosed, whereas a DAI count≥6 is associated to poor outcome. Magnetic resonance imaging classification did not have a prognosis value even in patients with pure DAI 6).