One-year and three-year mortality prediction in adult major blunt trauma survivors: a National Retrospective Cohort Analysis.

BACKGROUND: Survivors of trauma are at increased risk of dying after discharge. Studies have found that age, head injury, injury severity, falls and co-morbidities predict long-term mortality. The objective of our study was to build a nomogram predictor of 1-year and 3-year mortality for major blunt trauma adult survivors of the index hospitalization. METHODS: Using data from the Singapore National Trauma Registry, 2011-2013, we analyzed adults aged 18 and over, admitted after blunt injury, with an injury severity score (ISS) of 12 or more, who survived the index hospitalization, linked to death registry data. The study population was randomly divided 60/40 into separate construction and validation datasets, with the model built in the construction dataset, then tested in the validation dataset. Multivariable logistic regression was used to analyze 1-year and 3-year mortality. RESULTS: Of the 3414 blunt trauma survivors, 247 (7.2%) died within 1 year, and 551 (16.1%) died within 3 years of injury. Age (OR 1.06, 95% CI 1.05-1.07, p < 0.001), male gender (OR 1.53, 95% CI 1.12-2.10, p < 0.01), low fall from 0.5 m or less (OR 3.48, 95% CI 2.06-5.87, p < 0.001), Charlson comorbidity index of 2 or more (OR 2.26, 95% CI 1.38-3.70, p < 0.01), diabetes (OR 1.31, 95% CI 1.68-2.52, p = 0.04), cancer (OR 1.76, 95% CI 0.94-3.32, p = 0.08), head and neck AIS 3 or more (OR 1.79, 95% CI 1.13-2.84, p = 0.01), length of hospitalization of 30 days or more (OR 1.99, 95% CI 1.02-3.86, p = 0.04) were predictors of 1-year mortality. This model had a c-statistic of 0.85. Similar factors were found significant for the model predictor of 3-year mortality, which had a c-statistic of 0.83. Both models were validated on the second dataset, with an overall accuracy of 0.94 and 0.84 for 1-year and 3-year mortality respectively. CONCLUSIONS: Adult survivors of major blunt trauma can be risk-stratified at discharge for long-term support.

Anatomic Targeting of the Optimal Location for Thalamic Deep Brain Stimulation in Patients with Essential Tremor.

BACKGROUND: Thalamic deep brain stimulation (DBS) is an effective strategy for treatment of essential tremor (ET). With limitations of imaging modalities, targeting largely relies on indirect methods. This study was designed to determine the optimal target for DBS in ET and construct a targeting method based on probabilistic maps. METHODS: Patients with ET who had sustained tremor reduction at 1 year and optimal microelectrode recordings were selected. Stimulation volume was individually modeled in standard space, and a final optimal region was derived for the whole population. A fornix (FX) targeting method was developed to determine the location of the optimal stimulation site relative to the FX and posterior commissure (PC) in the anteroposterior plane, the border between the thalamus and internal capsule in the mediolateral plane, and the anterior commissure (AC)-PC (AC-PC) plane in the dorsoventral axis. Following comparative analyses with other standard indirect methods (25% of AC-PC and PC + 6 mm), the FX method was studied in relation to diffusion tensor imaging. RESULTS: Using the FX method, the optimal stimulation site was at the intersection of two thirds and one third of the PC-FX distance (mean of 28% ± 1.5 AC-PC length) and 4 mm medial to the lateral border of the thalamus. Compared with previously used methods, there was a significant reduction in variability of the optimal stimulation site with the FX method. The target defined using this strategy was found to be within the boundaries of the dentatorubrothalamic tract. CONCLUSIONS: The FX method may be an additional targeting strategy in patients undergoing thalamic DBS surgery.

Speech and language adverse effects after thalamotomy and deep brain stimulation in patients with movement disorders: A meta-analysis.

BACKGROUND: The thalamus has been a surgical target for the treatment of various movement disorders. Commonly used therapeutic modalities include ablative and nonablative procedures. A major clinical side effect of thalamic surgery is the appearance of speech problems. OBJECTIVE: This review summarizes the data on the development of speech problems after thalamic surgery. METHODS: A systematic review and meta-analysis was performed using nine databases, including Medline, Web of Science, and Cochrane Library. We also checked for articles by searching citing and cited articles. We retrieved studies between 1960 and September 2014. RESULTS: Of a total of 2,320 patients, 19.8% (confidence interval: 14.8-25.9) had speech difficulty after thalamotomy. Speech difficulty occurred in 15% (confidence interval: 9.8-22.2) of those treated with a unilaterally and 40.6% (confidence interval: 29.5-52.8) of those treated bilaterally. Speech impairment was noticed 2- to 3-fold more commonly after left-sided procedures (40.7% vs. 15.2%). Of the 572 patients that underwent DBS, 19.4% (confidence interval: 13.1-27.8) experienced speech difficulty. Subgroup analysis revealed that this complication occurs in 10.2% (confidence interval: 7.4-13.9) of patients treated unilaterally and 34.6% (confidence interval: 21.6-50.4) treated bilaterally. After thalamotomy, the risk was higher in Parkinson's patients compared to patients with essential tremor: 19.8% versus 4.5% in the unilateral group and 42.5% versus 13.9% in the bilateral group. After DBS, this rate was higher in essential tremor patients. CONCLUSION: Both lesioning and stimulation thalamic surgery produce adverse effects on speech. Left-sided and bilateral procedures are approximately 3-fold more likely to cause speech difficulty. This effect was higher after thalamotomy compared to DBS. In the thalamotomy group, the risk was higher in Parkinson's patients, whereas in the DBS group it was higher in patients with essential tremor. Understanding the pathophysiology of speech disturbance after thalamic procedures is a priority. © 2017 International Parkinson and Movement Disorder Society.

The effect of dexmedetomidine on the firing properties of STN neurons in Parkinson's disease.

Dexmedetomidine (an alpha-2 adrenergic agonist) sedation is commonly used during subthalamic nucleus (STN) deep-brain stimulation (DBS). Its effects on the electrophysiological characteristics of human STN neurons are largely unknown. We hypothesised that dexmedetomidine modulates the firing rates and bursting of human STN neurons. We analysed microelectrode recording (MER) data from patients with Parkinson's disease who underwent STN DBS. A 'Dex bolus' group (dexmedetomidine bolus prior to MER; 27 cells from seven patients) was compared with a 'no sedation' group (29 cells from 11 patients). We also performed within-patient comparisons with varying dexmedetomidine states. Cells were classified as dorsal half or ventral half based on their relative location in the STN. Neuronal burst and oscillation characteristics were analysed using the Kaneoke-Vitek methodology and local field potential (LFP) oscillatory activity was also investigated. Dexmedetomidine was associated with a slight increase in firing rate (41.1 ± 9.9 vs. 34.5 ± 10.6 Hz, P = 0.02) but a significant decrease in burstiness (number of bursts, P = 0.02; burst index, P < 0.001; percentage of spikes in burst, P = 0.002) of dorsal but not ventral STN neurons. This was not associated with modulation of beta oscillations in the spike-oscillations analysis(beta peak, P = 0.4; signal-to-noise ratio in the beta range for spikes and bursts, P = 0.3 and P = 0.5, respectively) and LFP analysis (Beta power, P = 0.17). As bursting pattern is often used to identify STN and guide electrode placement, we recommend that high-dose dexmedetomidine should be avoided during DBS surgery.

Comparison of polyetheretherketone and titanium cranioplasty after decompressive craniectomy.

OBJECTIVE: To characterize complication and failure rates and outcomes of patients who underwent cranioplasty with polyetheretherketone (PEEK) and titanium implants and to compare complication and failure rates between the 2 implants. METHODS: A retrospective cohort study of patients who underwent cranioplasty with PEEK patient-specific implant (PEEK Optima-LT) and preformed titanium mesh at the National Neuroscience Institute, Singapore, between January 2001 and February 2012 was performed. Data related to initial decompressive craniectomy and cranioplasty, associated complications after cranioplasty, and indication for revision or removal of implants were collected. Cranioplasty failure was defined as revision or removal of a patient's implant. RESULTS: Overall complication rates for PEEK and titanium cranioplasty were 25.0% and 27.8%, respectively. The combined complication rate was 27.3%. A trend toward increase in exposed implant in titanium cranioplasty compared with PEEK cranioplasty was observed (P = 0.074). There were 3 of 24 (12.5%) cranioplasty failures with PEEK, and 27 of 108 (25%) cranioplasty failures with titanium (P = 0.129). Previous deep infection in patients after decompressive craniectomy was associated with cranioplasty complications (odds ratio, 23.3; confidence interval, 3.00-180.5; P = 0.003) and failure (odds ratio, 22.5; confidence interval, 2.82-179.0; P = 0.003). CONCLUSIONS: The findings from this study highlight that cranioplasty is associated with significant complications, including the necessity for reoperation. It is hoped that the information in this study will provide better understanding of the risks associated with PEEK and titanium cranioplasty and contribute to decision making by the clinician and patient.

A computed tomography morphometric study of occipital bone and C2 pedicle anatomy for occipital-cervical fusion.

BACKGROUND: Occipital-cervical fusion (OCF) has been used to treat instability of the occipito-cervical junction and to provide biomechanical stability after decompressive surgery. The specific areas that require detailed morphologic knowledge to prevent technical failures are the thickness of the occipital bone and diameter of the C2 pedicle, as the occipital midline bone and the C2 pedicle have structurally the strongest bone to provide the biomechanical purchase for cranio-cervical instrumentation. The aim of this study was to perform a quantitative morphometric analysis using computed tomography (CT) to determine the variability of the occipital bone thickness and C2 pedicle thickness to optimize screw placement for OCF in a South East Asian population. METHODS: Thirty patients undergoing cranio-cervical junction instrumentation during the period 2008-2010 were included. The thickness of the occipital bone and the length and diameter of the C2 pedicle were measured based on CT. RESULTS: The thickest point on the occipital bone was in the midline with a maximum thickness below the external occipital protuberance of 16.2 mm (±3.0 mm), which was thicker than in the Western population. The average C2 pedicle diameter was 5.3 mm (±2.0 mm). This was smaller than Western population pedicle diameters. The average length of the both pedicles to the midpoint of the C2 vertebral body was 23.5 mm (±3.3 mm on the left and ±2.3 mm on the right). CONCLUSIONS: The results of this first study in the South East Asian population should help guide and improve the safety in occipito-cervical region instrumentation. Thus reducing the risk of technical failures and neuro-vascular injury.

Value of routine early post-operative computed tomography in determining short-term functional outcome after drainage of chronic subdural hematoma: An evaluation of residual volume.

BACKGROUND: Computed tomography (CT) scans are widely used in managing chronic subdural hematoma (CSDH). Factors that determine early post-operative volume have not been examined. The value of routine early post-operative residual volume have not been evaluated. Our study aims to compare pre-operative and early post-operative CT findings to determine the factors affecting residual hematoma and evaluate if early post-operative CT scans are useful in the management of CSDH. METHODS: Forty-three patients who underwent burr hole drainage of unilateral CSDH from August 2006 to January 2013 and had routine post-operative CT scans within 48 hours of surgery were selected. Data regarding age, sex, neurological deficit, Glasgow Coma Scale (GCS), pre-existing medical conditions, use of antiplatelets or anticoagulation, operative time, usage of drains, and number of burr holes were obtained. The pre-operative CSDH volume, CSDH density, and midline shift were measured. Residual volume was calculated from early post-operative CT scans. Clinical outcome was evaluated with Glasgow Outcome Scale (GOS) at the time of discharge. Statistical analysis was performed to look for correlation between the pre-operative factors and residual volume, and the residual volume and GOS. RESULTS: Pre-operative volume was found to correlate significantly with post-operative residual volume. There was no significant correlation between all other pre-operative factors and residual volume. There was also no correlation between residual volume and GOS at discharge. CONCLUSION: Routine post-operative CT brain for burr hole drainage of CSDH may be unnecessary in view of the good predictive value of pre-operative volume, and also because it is not predictive of the clinical outcome.

Benign scalp lump as an unusual presentation of extranodal Rosai-Dorfman disease.

BACKGROUND: Rosai-Dorfman disease (RDD) is a rare benign histioproliferative disease. It is typically characterized by benign histiocyte proliferation with lymphadenopathy, fever, and leukocytosis and was first described in 1969 by Rosai and Dorfman. Extranodal involvement has been reported in approximately up to 43% of the cases with isolated central nervous system (CNS) manifestations being even rarer. CASE DESCRIPTION: We report our management of a 41-year-old female with extranodalpurely CNS RDD presenting as a benign scalp lump. Her lump progressed from an asymptomatic benign lesion to one causing localized cerebral edema. Treatment was surgical excision of both the cervical and CNS lesions achieving complete removal of the lesions and resolution of her symptoms. CONCLUSION: RDD is a rare condition and isolated CNS RDD is even less common. Benign scalp lumps have a myriad of differential diagnoses, but RDD should be a consideration in the presence of preexisting RDD lesions at other sites given its potential to progress and result in morbidity. It is imperative to be aware that symptoms may be especially deceiving as the absence of lymphadenopathy may point away from RDD as the diagnosis.

Synchronous multicentric glioblastoma with PNET and O subtypes: Possible pathogenesis.

BACKGROUND: Glioblastomas (GBM) are highly infiltrative, cellular and mitotically active tumors with large histologic variations within and between tumours. Several subtypes have been described including the GBM with oligodendroglial differentiation (GBM-O) and primitive neuroectodermal tumour components (GBM-PNET). We report the first described case of a patient with synchronous multi-centric GBM-O and GBM-PNET components. CASE DESCRIPTION: A patient, who presented with a short history of progressive headache and difficulty with memory recall, was found on MRI imaging to have two intracranial lesions. These showed heterogeneous enhancement and were found in the left frontal and left temporal regions. The patient underwent gross total resection of these two lesions which were found to show GBM-O and GBM-PNET differentiations. CONCLUSION: Although tumour cell migration in the context of GBM is a well-recognized phenomenon, the traditional hypothesis is not able to satisfactorily explain this case of multicentric GBM whereby the two lesions demonstrate different cell origins. More current understanding of the migratory pathways from the subventricular zone provide an alternate and plausible pathway that fits our patient's unusual diagnosis.

Uses and limitations of indocyanine green videoangiography for flow analysis in arteriovenous malformation surgery.

Intra-operative indocyanine green (ICG) videoangiography is a useful addition to cerebrovascular neurosurgery. ICG videoangiography is useful in different phases of arteriovenous malformation (AVM) surgery. Additionally, it can be used to perform semi-quantitative flow analysis. We reviewed our initial assessment of 24 patients who underwent ICG videoangiography during AVM surgery to assess the utility and limitations of the technique as well as to demonstrate semi-quantitative flow analysis, a new capability of ICG videoangiography. Over the course of 3 years, we performed 49 ICG videoangiographies in 24 patients with AVM. In 85% of the pre-resection videos, ICG was useful in localising the arterial feeders, the draining veins and the nidus. Intra-resection ICG videos were recorded for eight of the 23 patients (the ICG from one patient was missing). Post-resection ICG videos were recorded for 14 out of the 23 patients, which were useful in confirming no evidence of nidus in the exposed resection cavity and an absence of flow in the main draining vein. Semi-quantitative flow analysis was performed in eight patients with superficial AVM. The average T(½) peak intensities (time to 50% of peak intensity) were 32 s, 33.5 s, and 35.6 s for the arterial feeder, the draining vein and normal cortex, respectively. The arteriovenous T(½) peak time was 1.5 s, and the arteriocortex T(½) peak time was 3.6 s. The T(½) peak fluorescence rates were 84 average intensity of fluorescence (AI)/s, 62.9 AI/s and 28.7 AI/s, for the arterial feeder, the draining vein and normal cortex, respectively. Only one patient of 23 (4.3%) showed residual AVM on post-operative digital subtraction angiography or CT angiography despite negative intra-operative ICG. ICG videoangiography is a useful addition to AVM surgery, but it has some limitations. Flow analysis is a new capability that allows for semi-quantitative AVM perfusion analysis.

Evaluation of corticospinal excitability in cervical myelopathy, before and after surgery, with transcranial magnetic stimulation: a pilot study.

PURPOSE: A pilot study to examine the impact of cervical myelopathy on corticospinal excitability, using transcranial magnetic stimulation, and to investigate whether motor evoked potential (MEP) and silent period (SP) recruitment curve (RC) parameters can detect changes in corticospinal function pre- and post-surgery. METHODS: We studied six cervical myelopathy patients undergoing surgery and six healthy controls. Clinical and functional scores and neurophysiological parameters were examined prior to and 3 months following the surgery. RESULTS: MEP latencies for abductor pollicis brevis (APB) and tibialis anterior (TA) muscles and central motor conduction time were prolonged pre- and post-surgery; SP durations were differentially altered. There were significant differences in parameters of RCs for (1) MEP area in APB (max values, S50) and TA (slope) between controls and patients pre- and post-surgery and (2) SP duration in APB (max values) between patients pre-surgery and controls. CONCLUSIONS: The findings of this pilot study suggest an uncoupling of excitatory and inhibitory pathways, which persists at 3 months following cord decompression. RCs for MEP and SP at 3 months provide more information on the functional status of the cord and prompts for a longer term follow-up.

Anaplastic supratentorial cortical ependymoma presenting as a butterfly lesion.

BACKGROUND: Anaplastic cortical ependymomas are rare lesions with few cases reported in the literature. CASE DESCRIPTION: We present a unique case of an anaplastic cortical ependymoma in a 51-year-old female presenting as a butterfly lesion with involvement of both frontal lobes. The patient underwent gross total resection of her tumor with further adjuvant treatment. We present the findings in our case and review the literature surrounding supratentorial ependymomas and their treatment outcomes. CONCLUSION: Rarely, cortical ependymoma can present as a butterfly lesion and should be considered in the differential diagnosis of such lesions in adults.

European survey of surgical strategies for the management of severe acute pancreatitis.

OBJECTIVES: This study is the first pan-European survey of surgical strategies for the management of severe acute pancreatitis. METHODS: A questionnaire survey was undertaken of the 866 members of the European chapter of the International Hepato-Pancreato-Biliary Association (IHPBA). There were 329 replies from practicing clinicians giving a response rate of 38%. RESULTS: The modal case volume was 11-20 patients per year. Severity stratification was used by 324 (99%) respondents with the Ranson score being the most popular. Antibiotic prophylaxis was utilized by 239 (73%) with the median duration being 7 days (range 1-28; 95% CI: 8-9). Fine needle aspiration of necrosis was undertaken by 174 (53%) and 131 would operate on a patient with a positive result. There was no consensus on optimum timing of surgery. CONCLUSIONS: The results of this first pan-European questionnaire demonstrate wide variations in care. Overall, the findings provide a unique insight into the current management of severe acute pancreatitis in Europe.