As conceived by Wilder Penfield the Montreal Neurological Institute (MNI) integrated neurology, neurosurgery, and allied disciplines within a single institution, where research and teaching complemented patient care. The MNI’s success influenced the creation of the National Institute of Neurological Diseases and Blindness (NINDB), as Pearce Bailey, its first Director, sought to replicate the MNI’s clinical and research model. He turned to MNI trainees Maitland Baldwin and Milton Shy to head the NINDB’s Surgical and Medical Neurology Branches, respectively. They in turn recruited other MNI trainees who continued their work at the NINDB bringing clinical neuroscience to the USA.

The variable rate of infarct progression in acute ischemic stroke as assessed by various thresholds excludes a substantial proportion of patients due to time or core constraints. We evaluated 106 patients with any-type occlusion to compare these thresholds and assessed performance of hypoperfusion index (HI) for fast and slow rate of infarct progression. Seven (12.5%) were classified fast progressors and 23 (46%), 25 (50%), 12 (24%), and 33 (66%) slow progressors using different core and time criteria. In comparison, HI categorized 100% (n = 106) of cohort with optimal cutoff 0.5 for any-type occlusion (slow progressors: HI ≤ 0.5), sensitivity/specificity 100%/91%, AUC 0.94, and indicative of eligibility for reperfusion and clinical outcomes (median 90-day modified Rankin Scale; 2 for HI ≤ 0.5 versus 5). Estimation of progressors by HI seems comprehensive but needs external validation.

Background: Women are reported to have worse outcomes than men following ischemic stroke despite similar treatment effects for thrombolysis and endovascular treatment. Methods: We performed a post-hoc analysis of patients with acute ischemic stroke and intracranial occlusion enrolled in INTERRSeCT, an international prospective cohort study. We compared workflow times, reperfusion therapy choices, and 90-day modified Rankin scale (mRS) scores. Results: We included 575 patients, mean age 70.2 years (SD: 13.1) and 48.5% female. There were no significant sex differences in onset-to-CT (males: 115 minutes [IQR: 72-171], females: 114 minutes [IQR: 75-196] ) or CT-to-thrombolysis time (males: 24 minutes [IQR: 17-32], females: 23 minutes [IQR: 18-36]). However, female participants had a 12-minute faster CT-to-groin-puncture time, p=0.001. Reperfusion therapies did not significantly differ by sex. Reperfusion therapies included thrombolysis alone (males: 46%, females: 49%), EVT alone (males: 34%, females: 34%), thrombolysis plus EVT (males: 8%, females 9%) and conservative management (males: 12%, females: 8%). Median 90-day mRS was 2 (IQR: 1-4) in both males and females, p=0.1. Conclusions: In the INTERRSeCT cohort, rates of reperfusion therapy, workflow times and 90-day outcomes were similar between sexes, suggesting that women are not subject to any poorer performance in key quality indicators for reperfusion treatment for acute stroke.

IgG4-related disease (IgG4-RD) is a rare and often misdiagnosed disorder with limited literature that highlights the different neurological presentations of this treatable disease. The diagnosis of IgG4-RD could be challenging, while imaging is fundamental for the diagnosis, biopsy is considered the gold standard. Most cases respond well to steroids and immunosuppressive therapy. This is a case series study that illustrates the varied neurological presentations of IgG4-RD through three different patients that were followed at the Montreal Neurological Institute. This paper takes you through the diagnostic strategy that we followed to accurately diagnose and treat those patients.

Hyperglycemia is reported to predict worse outcome in patients with stroke, including intracerebral hemorrhage (ICH). In 83 consecutive cases of ICH at a tertiary stroke center, hyperglycemia (serum glucose >7 mmol/L) compared to normoglycemia at presentation was associated with higher rates of in-hospital mortality (51.2% vs. 26.2%, OR 2.3, CI 1.2–7.6, p = 0.02). The association with in-hospital mortality withstood adjustment for age, ICH volume, intraventricular hemorrhage, and infratentorial ICH location, but not baseline Glasgow Coma Scale. Acute hyperglycemia is associated with in-hospital mortality in spontaneous ICH patients, though this may be an indirect, rather than a causal relationship.

The National Institutes of Health Toolbox-Cognition Battery (NIHTB-CB) is a tablet-based cognitive assessment intended for individuals with neurological diseases of all ages. NIHTB-CB practice effects (PEs), however, need clarification if this measure is used to track longitudinal change. We explored the test–retest PEs on NIHTB-CB performance at 3 months in young healthy adults (n = 22). We examined corrected T-scores normalized for demographic factors and calculated PEs using Cohen’s d. There were significant PEs for all NIHTB-CB composite scores and on 4/7 subtests. This work suggests the need to further assess NIHTB-CB PEs as this may affect the interpretation of study results incorporating this battery.

Background: We aim to assess the role of quantitative electroencephalography (QEEG) derived indices to predict post-stroke disability. Methods: We included observational studies (sample-size≥10) of patients with stroke who underwent EEG and a follow-up outcome assessment was available either in form of a modified Rankin scale (mRS) or National Institute of stroke scale (NIHSS) or Fugl-Meyer scale (FMA). QEEG indices analyzed were delta-alpha ratio (DAR), delta-theta-alpha-beta ratio (DTABR), brain symmetry (BSI) and pairwise derived brain symmetry (pdBSI). Results: Twelve studies (11 had only ischemic stroke, and one had both ischemic and hemorrhagic stroke), including 513 participants were included for meta-analysis. Higher DAR was associated with worse mRS (n=300, Pearson’s r 0.26, 95% CI 0.21-0.31). Higher DTABR was associated with worse mRS (n=337, r 0.32, 95% CI 0.26-0.39). Higher DAR was associated with higher NIHSS (n=161, r 0.42, 95% CI0.24-0.6). Higher DTABR was associated with higher NIHSS (n=172, r 0.49, 95% CI 0.31-0.67). pdBSI was inversely associated with FMA (n=20, r-0.50 95% CI -0.86-(-0.14)) and BSI was not associated with FMA (n=21, r -0.3 95% CI -0.81-0.22). Conclusions: QEEG-derived indices have the potential to assess post-stroke disability. Adding QEEG to the clinical and imaging biomarkers may help in better prediction of post-stroke recovery.

PROSPERO 2022 CRD42022292281

Dural arteriovenous fistulas (DAVFs) are direct shunts between extracranial or meningeal arteries and dural sinuses, dural veins, or cortical veins. They account for 10%–15% of all intracranial vascular malformations. DAVFs are classified according to two classification systems, Borden and Cognard, both of which are based on the venous drainage pathway and presence of antegrade or retrograde venous flow. A multidisciplinary approach using endovascular techniques has become the mainstay of treatment. We present two cases of DAVF with cortical venous drainage (Borden type 3) that were successfully treated using a transvenous approach via the draining subarachnoid veins.

Poststroke visual impairment (VI) negatively affects rehabilitation potential and quality of life for stroke survivors. In this cross-sectional observational study, stroke survivors and providers were surveyed to quantify perspectives regarding care for poststroke VI in Alberta, Canada (n = 46 survivors; n = 87 providers). Few patients (35%) felt prepared to cope with VI at the time of discharge from acute stroke and inpatient rehabilitation settings. Less than 25% of stroke survivors, and <16% of providers, felt referral processes were adequate. 95.2% of providers and 82% of stroke survivors advocated for a provincial clinical pathway to improve care quality for poststroke VI.

Recombinant tissue plasminogen activator improves outcomes in acute ischemic stroke. Alteplase may result in thrombus migration (TM) distally to a critical arterial supply that can worsen perfusion to eloquent brain tissue. Alteplase-related stroke recanalization and clot migration in vertebral artery (VA) occlusion whereby the clot migrates to the basilar artery (BA) may be harmful. We identified seven subjects with isolated symptomatic vertebral occlusion. Two cases suffered early neurologic deterioration due to TM from VA to BA following alteplase. Precautionary transfer to thrombectomy centers may be warranted in alteplase-treated symptomatic VA occlusions in case of migration to basilar occlusion.

Previous literature on roller coaster injuries focuses on catastrophic injuries. We conducted a retrospective study of 31 adults with headache or dizziness after roller coaster rides. Twenty five of 31 (81%) patients presented with new or worsening headache, predominantly migraine (15/25, 60%), including 8/25 (32%) with chronic migraine. Of the chronic migraine patients, 4/8 (50%) already had the diagnosis and presented with an exacerbation. Five of the 25 (20%) were ultimately found to have a cerebrospinal fluid (CSF) leak. While persistent symptoms appear to be relatively rare, patients with chronic migraine and potential CSF leaks should consider skipping these attractions.

The Royal College Comprehensive Objective Examination in Neurology provides certification for Canadian neurologists and consists of a written examination and the Observed Structured Clinical Encounter (OSCE). The OSCE portion of the certification involves residents visiting several patient stations where they address case scenarios with an examiner. Unfortunately, residents lack exam preparation time due to demanding work hours. In response to resident needs, we created a novel, virtual preparation OSCE program – “prepOSCE” – and evaluated its efficacy. The prepOSCE program employed a proprietary virtual solution from CTC Communications Corp. Ten virtual sessions accommodated 70 residents totally. Seven Canadian physicians and two co-chairs created case scenarios for the stations. On session day, seven residents arrived in a virtual plenary room for briefing followed by assignment to a station by CTC. Residents then moved virtually through prepOSCE stations a different examiner and case scenario in each. Following their session, residents and evaluators were surveyed to capture experiences. The average program rating was 4.22 out of 5 (n = 36 residents of 70 residents who participated in the program) and 4.35 (n = 17 evaluators). Ninety-two percent of residents agreed or strongly agreed that they would recommend this program to their peers; they would like prepOSCE to continue next year; and the program was relevant and added value to their studies. The positive feedback received from prepOSCE participants indicates there is a need for a program like prepOSCE. This model has potential for expansion and it is hoped that specialties outside of neurology could benefit from a similar program.

A retrospective review of 29 patients with neurovascular compression syndrome (NVCS) involving the anterior visual pathway was conducted. Various patterns of NVCS and visual defects were identified, most commonly involving the optic nerve and internal carotid artery. Most patients were stable, except one with progressive visual field defects. Although mostly asymptomatic, NVCS can rarely cause compressive optic neuropathy. NVCS should be kept in the differential diagnosis of normal tension glaucoma, especially with progressive visual loss despite treatment. Patients with progressive visual loss may require decompression surgery. Non-contrast computed tomography scan may miss NVCS, and magnetic resonance imaging is diagnostic.

There is considerable variability in the management of diffuse low-grade gliomas (LGGs). To characterize treatment paradigms, a survey of Canadian neurosurgeons was performed with forty neurosurgeons responding. Their responses show that the management of patients with LGGs has evolved in the past decade and findings from the RTOG9802 trial have been integrated into the practice of Canadian neurosurgeons. Most respondents stated that the patient selection and treatment strategy advocated by the RTOG9802 trial needs further evaluation. Overall, there is a trend toward more aggressive surgical resections, and future investigations will have to more accurately stratify patient risk profiles.

Background: To clarify the landscape of molecular diagnoses (MDs) in early-onset epilepsy individuals, we determined the prevalent MDs stratified by age at seizure onset (SO) and the time to MD in children with SO <36 months of life. Methods: A panel of up to 302 genes associated with epilepsy was utilized and ordering physicians provided the age of SO. Diagnostic yield analyses were performed for SO ages including <1 mo, 1-2 mo, 3-5 mo, 6-11 mo, 12-23 mo, and 24-35 mo. The time to MD (MD age - SO age) was determined for the top 10 genes in each SO category. Results: 15,074 individuals with SO <36 months of life were tested. Predominant MD findings are as follows: KCNQ2 in neonates with SO at <1mo, KCNQ2 and CDKL5 for SO between 1-2 mo, PRRT2 and SCN1A for SO between 3-11 mo, and SCN1A for SO between 12-36 months. The median time to MD varied by gene. For example, there was no delay in the median time to MD for the GLDC, KCNQ2, and SCN2A genes while the median delay for MECP2, SLC2A1, and other genes was ≥ 12 months. Conclusions: These data highlight the importance of comprehensive early testing in children with early-onset epilepsy.