Surface electroencephalogram (EEG) recording remains the gold standard for noninvasive assessment of electrical brain activity. It is the most efficient way to diagnose and classify epilepsy syndromes as well as define the localization of the epileptogenic zone. The EEG is useful for management decisions and for establishing prognosis in some types of epilepsy. Electroencephalography is an evolving field in which new methods are being introduced. The Canadian Society of Clinical Neurophysiologists convened an expert panel to develop new national minimal guidelines. A comprehensive evidence review was conducted. This document is organized into 10 sections, including indications, recommendations for trained personnel, EEG yield, paediatric and neonatal EEGs, laboratory minimal standards, requisitions, reports, storage, safety measures, and quality assurance.

Seizures are important complications following a subarachnoid hemorrhage (SAH). The evidence for the use of antiepileptic drugs (AEDs) in treatment and prevention of those seizures is conflicting. The purpose of this review is to provide an up-to-date evidence summary of the incidence and outcomes of seizures following an SAH as well as the use of different AEDs post-SAH in order to evaluate the need for seizure prophylaxis, the choice of AEDs, and their dosing considerations in SAH patients. A literature search of PubMed, Medline, Embase, and the Cochrane Library was performed. A total of 37 studies were reviewed, mostly observational. Definitions of seizures in temporal relation to initial hemorrhage were variable. Similarly, the rates of seizures varied in the literature, ranging from 0 to 31%. Given the reported adverse outcomes associated with AED usage, seizure prophylaxis is not warranted. Levetiracetam appears to be better tolerated than phenytoin in SAH patients, though further research is needed. Higher initial dosing of levetiracetam might be required due to its enhanced clearance in SAH patients. In conclusion, there is a lack of quality evidence to definitively recommend the use of one AED over another. Further prospective research comparing the use of different AEDs in patients with an SAH is needed.

This review aims at summarizing and discussing previous and recent findings concerning the cerebral manifestations of mitochondrial disorders (MIDs). MIDs frequently present as mitochondrial multiorgan disorder syndrome (MIMODS) either already at onset or later in the course. After the muscle, the brain is the organ second most frequently affected in MIMODS. Cerebral manifestations of MIDs are variable and may present with or without a lesion on imaging or functional studies, but there can be imaging/functional lesions without clinical manifestations. The most well-known cerebral manifestations of MIDs include stroke-like episodes, epilepsy, headache, ataxia, movement disorders, hypopituitarism, muscle weakness, psychiatric abnormalities, nystagmus, white and gray matter lesions, atrophy, basal ganglia calcification, and hypometabolism on 2-deoxy-2-[fluorine-18]fluoro-D-glucose positron-emission tomography. For most MIDs, only symptomatic therapy is currently available. Symptomatic treatment should be supplemented by vitamins, cofactors, and antioxidants. In conclusion, cerebral manifestations of MIDs need to be recognized and appropriately managed because they strongly determine the outcome of MID patients.

Background: To introduce the “uniform cortex sign” (UCS) and evaluate its performance as a diagnostic test for the presence of diffuse cortical injury (DCI). Methods: The study was approved by our institutional review board. Three experienced neuroradiologists were given a tutorial on the UCS. They were subsequently presented with 14 cases (7 control patients and 7 DCI patients with the UCS) in random order and asked to determine whether the UCS was present. Each case consisted of selected DWI, T2-weighted, and FLAIR images from unenhanced 1.5T MRI examinations. A consensus result for each case was determined by unanimity or majority rule. Results: All control patients were correctly identified as normal by all neuroradiologists (7/7). The UCS was correctly identified in 86% of DCI patients (6/7). UCS interrater agreement was high (multirater κ=0.81). Conclusions: This small study shows that the UCS can identify DCI, especially in patients with hypoxic-ischemic encephalopathy. The UCS can be subtle, hence the reader must be vigilant for this finding. The accuracy of the UCS may depend on the extent of cortical injury and time between injury and MRI. Also, a UCS may be reversible, as in our case of viral meningoencephalitis.

Background: The current study involves a national survey of healthcare providers who offer services for individuals with a variety of neurological conditions. It aims to describe the provision of health and community-based services as well as the admission criteria, waitlist practices, and referral sources of these services. Methods: An online survey was directed at administrators/managers from publicly funded hospital programs, long-term care homes, and community-based healthcare provider agencies that were believed to be providing information and/or services to patients with a variety of neurological conditions. Results: Approximately 60% (n=254) of respondents reported providing services in either urban/suburban areas or rural/remote areas only, whereas the remaining 40% (n=172) provided services regardless of patient location. A small proportion of respondents reported providing services for individuals with dystonia (28%), Tourette syndrome (17%), and Rett syndrome (13%). There was also a paucity of diverse healthcare professionals across all institutions, but particularly mental healthcare professionals in hospitals. Lastly, the majority of respondents reported numerous exclusion criteria with regard to service provision, including prevalent comorbid conditions. Conclusions: If the few services provided for these neurological patient populations exclude common comorbidities, it is likely that there will be no other place for these individuals to seek care.

Background: Standardized data collection for traumatic brain injury (TBI) (including concussion) using common data elements (CDEs) has strengthened clinical care and research capacity in the United States and Europe. Currently, Ontario healthcare providers do not collect uniform data on adult patients diagnosed with concussion. Objective: The Ontario Concussion Care Strategy (OCCS) is a collaborative network of multidisciplinary healthcare providers, brain injury advocacy groups, patient representatives, and researchers with a shared vision to improve concussion care across the province, starting with the collection of standardized data. Methods: The International Framework of Functioning Disability and Health was selected as the conceptual framework to inform the selection of CDEs. The CDEs recommended by the OCCS were identified using key literature, including the National Institute of Neurological Disorders and Stroke–Zurich Consensus Statements for concussion in sport and the Ontario Neurotrauma Foundation Concussion/mTBI clinical guidelines. Results: The OCCS has recommended and piloted CDEs for Ontario that are readily available at no cost, clinically relevant, patient friendly, easy to interpret, and recognized by the international scientific community. Conclusions: The implementation of CDEs can help to shift Ontario toward internationally recognized standard data collection, and in so doing yield a more comprehensive evidence-based approach to care while also supporting rigorous research.

Purpose: To examine the safety and tolerability of clinical graded aerobic treadmill testing in recovering adolescent moderate and severe traumatic brain injury (TBI) patients referred to a multidisciplinary pediatric concussion program. Methods: We completed a retrospective case series of two moderate and five severe TBI patients (mean age, 17.3 years) who underwent initial Buffalo Concussion Treadmill Testing at a mean time of 71.6 days (range, 55-87) postinjury. Results: Six patients completed one graded aerobic treadmill test each and one patient underwent initial and repeat testing. There were no complications. Five initial treadmill tests were completely tolerated and allowed an accurate assessment of exercise tolerance. Two initial tests were terminated early by the treatment team because of neurological and cardiorespiratory limitations. As a result of testing, two patients were cleared for aerobic exercise as tolerated and four patients were treated with individually tailored submaximal aerobic exercise programs resulting in subjective improvement in residual symptoms and/or exercise tolerance. Repeat treadmill testing in one patient performed after 1 month of treatment with submaximal aerobic exercise prescription was suggestive of improved exercise tolerance. One patient was able to tolerate aerobic exercise following surgery for posterior glottic stenosis. Conclusions: Preliminary results suggest that graded aerobic treadmill testing is a safe, well tolerated, and clinically useful tool to assess exercise tolerance in appropriately selected adolescent patients with TBI. Future prospective studies are needed to evaluate the effect of tailored submaximal aerobic exercise prescription on exercise tolerance and patient outcomes in recovering adolescent moderate and severe TBI patients.

Background: Cross-clamp ischemia during carotid endarterectomy can be prevented with carotid bypass shunts in vulnerable patients identified by cerebral monitoring for ischemia. We compared transcranial cerebral oximetry (TCO) with carotid stump pressure measurements for selective shunt use. Methods: We prospectively collected data on 300 consecutive patients operated on under general anesthesia between 2009 and 2016. Shunts were inserted for a 10% or greater drop in cerebral saturations and/or a mean stump pressure less than 40 mmHg. Results: Seventy-five patients, 25% of the study population, were shunted. The indication was a combined desaturation and stump pressure in 38 (50% of the shunted group), desaturation alone in 11 patients (15%), and a low stump pressure alone in 26 patients (35%). There were no significant differences in baseline characteristics between those patients who were or were not shunted, except angiographic collateral blood supply, which was more commonly identified in patients who were not shunted. A watershed infarct occurred in just one patient with borderline TCO and stump pressure measurements in whom a shunt was not used. Conclusions: There was poor concordance between TCO and stump pressures, but using both in determining the need for shunt use almost eliminated cross-clamp ischemia in this series of 300 carotid endarterectomy patients.

Background: Subthalamic nucleus deep brain stimulation (STN–DBS) has become a standard treatment for many patients with Parkinson’s disease (PD). The reported clinical outcome measures for procedures done under general anesthesia (GA) compared to traditional local anesthetic (LA) technique are quite heterogeneous and difficult to compare. The aim of this systematic review and metaanalysis was to determine whether the clinical outcome after STN–DBS insertion under GA is comparable to that under LA in patients with Parkinson’s disease. Methods: The databases of Medline Embase, Cochrane library and Pubmed were searched for eligible studies (human trials, English language, published between 1946 and January of 2016). The primary outcome of this study was to assess the postoperative improvement in the symptoms, evaluated using either Unified Parkinson’s Disease Rating Scale (UPDRS) scores or levodopa equivalent dosage (LEDD) requirement. Results: The literature searches yielded 395 citations and six retrospective cohort studies with a sample size of 455 (194 in GA and 261 in LA) were included in the analysis. Regarding the clinical outcomes, there were no significant differences in the postoperative Unified Parkinson’s disease rating scale and levodopa equivalent drug dosage between the GA and the LA groups. Similarly, the adverse events and target accuracy were also comparable between the groups. Conclusions: This systematic review and meta-analysis shows that currently there is no good quality data to suggest equivalence of GA to LA during STN-DBS insertion in patients with PD, with some factors trending towards LA. There is a need for a prospective randomized control trial to validate our results.

Background: Several factors determine the choice of medications in patients with Parkinson’s disease (PD). We aimed to analyze the pattern of prescription of drugs in patients with PD before attending a tertiary-care center. Methods: The study included chart review of 800 PD patients attending the Department of Neurology of the National Institute of Mental Health and Neurosciences in Bangalore, India. Results: The mean age at onset was 51.1±11.8 years. The mean duration of illness was 41.7±43.6 months. At first visit, 79.4% (group 1, n=635) of patients were on medications, 10% (group 2, n=80) were on medications but later discontinued, and 10.6% (group 3, n=85) were drug-naïve. Overall, levodopa was prescribed in 94.8%, trihexyphenidyl in 40.4%, dopamine agonists in 23.2%, and amantadine in 17.2% either as monotherapy or in combination. In group 1, 37.8% were on monotherapy, with levodopa being the most commonly used agent (33.1%), followed by trihexyphenidyl (2.2%), dopamine agonists (1.6%), and amantadine (0.6%). Among those on polytherapy, levodopa plus trihexyphenidyl was the preferred combination (23.9%). In group 2, levodopa monotherapy was also most common (72.5%), followed by trihexyphenidyl monotherapy (7.5%). Conclusions: Levodopa and trihexyphenidyl were the most commonly prescribed drugs in our patients. A higher use of trihexyphenidyl could be due to its easy availability, low cost, and better tolerability in our patients, who were relatively young at the time of onset of their disease. The choice of antiparkinsonian medications at the primary and secondary care levels in India may be inappropriate, and newer guidelines tailored to the Indian context are warranted.

Background: The objective of this retrospective study was to evaluate the effectiveness and safety of Gamunex® (immune globulin [human] 10%; hereinafter “Gamunex”) when administered intravenously in the initial treatment of Guillain-Barré syndrome (GBS). The study was conducted as a postapproval commitment for Health Canada. Methods: A medical chart review for hospitalized patients diagnosed with GBS and treated with Gamunex (Gamunex 10% and IGIVnex® 10%; N=109; n=69 evaluable) was conducted at seven Canadian study centers in reverse chronological order. The primary endpoint for assessing effectiveness was the proportion of patients with treatment success compared with a prospectively defined historical effectiveness threshold for plasma exchange (PE) treatment (55.05%). Treatment success was assessed as ≥1 point improvement from baseline on the GBS Disability Scale or abbreviated GBS Disability Scale. Cases were not evaluable if treatment success, relapse, or treatment failure could not be determined by the available chart data. Results: Applying a conservative estimate with all nonevaluable patients (n= 40) classified as treatment failures, Gamunex treatment success was estimated at 57.8% (63 of 109 patients), which exceeded the predefined historical PE effectiveness threshold. In the evaluable population of this study, Gamunex treatment was successful in 91.3% of patients (63/69). Some 23 (21.1%) of 109 Gamunex-treated patients experienced ≥1 adverse event; the profile and frequency were consistent with the adverse events reported for Gamunex in the product’s labeling and with the natural clinical course of GBS. Conclusions: The effectiveness of Gamunex for treatment of GBS was comparable to PE therapy. Gamunex was observed to have an acceptable safety profile in this study population.

Background: ATP-sensitive K+ (KATP) channels couple metabolic state to cellular excitability. Activation of neuronal and astrocytic mitochondrial KATP (mitoKATP) channels regulates a variety of neuronal functions. However, less is known about the impact of mitoKATP on tonic γ-aminobutyric acid (GABA) inhibition. Tonic GABA inhibition is mediated by the binding of ambient GABA on extrasynaptic GABA A-type receptors (GABAARs) and is involved in regulating neuronal excitability. Methods: We determined the impact of activation of KATP channels with diazoxide (DIZ) on tonic inhibition and recorded tonic current from rat cortical layer 5 pyramidal cells by patch-clamp recordings. Results: We found that neonatal tonic current increased with an increase in GABA concentration, which was partially mediated by the GABA A-type receptor (GABAAR) α5, and likely the δ subunits. Activation of KATP channels resulted in decreased tonic current in newborns, but there was increased tonic current during the second postnatal week. Conclusions: These findings suggest that activation of KATP channels with DIZ regulates GABAergic transmission in neocortical pyramidal cells during development.

Severe longitudinally extensive transverse myelitis (LETM) can cause quadriplegia, marked sensory dysfunction, and respiratory failure. Some patients are unresponsive to conventional immune therapy. We report two cases of severe immune-mediated LETM requiring intensive care admission that failed to respond to high-dose corticosteroids, plasma exchange, intravenous immunoglobulin, and rituximab. Disease cessation and significant recovery was achieved after cyclophosphamide induction. In patients with severe acute immune-mediated LETM who fail to respond to corticosteroids and plasma exchange, cyclophosphamide induction should be considered. This agent and regimen provides a robust immunosuppressive response and can be induced rapidly. Cyclophosphamide effects and supportive evidence are discussed.

Cet article présente le processus de traduction en français du Charcot-Marie-Tooth Disease Pediatric Scale (CMTPedS), le seul outil de mesure validé évaluant la sévérité de la maladie chez les enfants atteints de CMT. Le processus de traduction utilisé s’inspire des lignes directrices de la Food and Drug Administration (FDA). La version préliminaire francophone du CMTPedS a été testée auprès de 14 enfants atteints. Les résultats de l’application démontrent que la passation a été bien tolérée par les enfants et s’est avérée conviviale pour les cliniciens. La disponibilité de cet outil en français semble prometteuse pour le suivi des enfants atteints et la réalisation d’essais clinique.