Since cannabis was legalized in Canada in 2018, its use among older adults has increased. Although cannabis may exacerbate cognitive impairment, there are few studies on its use among older adults being evaluated for cognitive disorders.

We analyzed data from 238 patients who attended a cognitive clinic between 2019 and 2023 and provided data on cannabis use. Health professionals collected information using a standardized case report form.

Cannabis use was reported by 23 out of 238 patients (9.7%): 12 took cannabis for recreation, 8 for medicinal purposes and 3 for both purposes. Compared to non-users, cannabis users were younger (mean ± SD 62.0 ± 7.5 vs 68.9 ± 9.5 years; p = 0.001), more likely to have a mood disorder (p < 0.05) and be current or former cigarette smokers (p < 0.05). There were no significant differences in sex, race or education. The proportion with dementia compared with pre-dementia cognitive states did not differ significantly in users compared with non-users. Cognitive test scores were similar in users compared with non-users (Montreal Cognitive Assessment: 20.4 ± 5.0 vs 20.7 ± 4.5, p = 0.81; Folstein Mini-Mental Status Exam: 24.5 ± 5.1 vs 26.0 ± 3.6, p = 0.25). The prevalence of insomnia, obstructive sleep apnea, anxiety disorders, alcohol use or psychotic disorders did not differ significantly.

The prevalence of cannabis use among patients with cognitive concerns in this study was similar to the general Canadian population aged 65 and older. Further research is necessary to investigate patients’ motivations for use and explore the relationship between cannabis use and mood disorders and cognitive decline.

Cortical excitability has been proposed as a novel neurophysiological marker of neurodegeneration in Alzheimer’s dementia (AD). However, the link between cortical excitability and structural changes in AD is not well understood.

To assess the relationship between cortical excitability and motor cortex thickness in AD.

In 62 participants with AD (38 females, mean ± SD age = 74.6 ± 8.0) and 47 healthy control (HC) individuals (26 females, mean ± SD age = 71.0 ± 7.9), transcranial magnetic stimulation resting motor threshold (rMT) was determined, and T1-weighted MRI scans were obtained. Skull-to-cortex distance was obtained manually for each participant using MNI coordinates of the motor cortex (x = −40, y = −20, z = 52).

The mean skull-to-cortex distances did not differ significantly between participants with AD (22.9 ± 4.3 mm) and HC (21.7 ± 4.3 mm). Participants with AD had lower motor cortex thickness than healthy individuals (t(92) = −4.4, p = <0.001) and lower rMT (i.e., higher excitability) than HC (t(107) = −2.0, p = 0.045). In the combined sample, rMT was correlated positively with motor cortex thickness (r = 0.2, df = 92, p = 0.036); however, this association did not remain significant after controlling for age, sex and diagnosis.

Patients with AD have decreased cortical thickness in the motor cortex and higher motor cortex excitability. This suggests that cortical excitability may be a marker of neurodegeneration in AD.

Canada’s National Microbiology Laboratory offers diagnostic testing of Creutzfeldt-Jakob disease (CJD) and related prion diseases. Since 2016, the highly sensitive and specific end-point quaking-induced conversion assay (EP-QuIC) of CSF samples has been used for antemortem CJD diagnostic testing alongside tests for surrogate biomarkers 14-3-3 and hTau. To assess EP-QuIC’s utility, we undertook a retrospective study of Canadian CJD diagnostic testing conducted between 2016 and 2024.

Using CJD CSF test results collected between 2016 and 2024, we analyzed the CJD incidence in Canada, estimated based on positive EP-QuIC tests. Multivariate regression models were used to further evaluate CJD CSF testing between CJD subtypes, genders, age groups and codon 129 genotypes.

From 2016 to 2024, the CJD incidence across Canada was estimated at 1.51 cases per million population per year. CJD incidence did not vary significantly across provinces, although a slight increase in CJD incidence was detected in New Brunswick due to increased sampling rates. EP-QuIC offered higher test sensitivity than both surrogate biomarker tests. Analysis of biomarker abundances and test positivity rates across biochemical subtypes revealed significant differences. We also detected variation in CSF test positivity rates across age groups and a trend of increasing biomarker abundance with age within EP-QuIC-negative cases. No significant variation was detected between males and females.

EP-QuIC exhibits exceptional specificity and sensitivity for antemortem diagnosis of CJD, providing a valuable tool for the diagnosis of human prion diseases and for improved surveillance.

Huntington’s disease (HD) is an inherited, neurodegenerative disorder caused by the expansion of an unstable CAG repeat sequence in the Huntingtin (HTT) gene. The prevalence of HD, allelic diversity, rate of novel expansions and the clinical correlates vary across populations.

We analyzed the diversity of alleles and their clinical correlates and examined the inheritance patterns and the pattern of instability of CAG repeats in a few families.

Clinical history and pedigree structure were collected from records or through interviews between 2016 and 2019. Genetic testing at the HD locus was done on clinical suspicion, or relatedness, after counseling. Descriptive statistics and correlation analysis were used.

Expanded repeats were detected in 239 individuals, including 232 who were symptomatic and 7 presymptomatic relatives. The number of CAG repeats (mean = 45.6) and age at onset (mean = 39.2 years) showed a strong inverse correlation (r = -0.67). We found atypical alleles such as 8 intermediate alleles (IA), 12 reduced penetrance alleles and 14 large (>60) expansion alleles corresponding to juvenile HD. Three individuals carried biallelic expansions. Paternal inheritance was more common, and the mean increase in repeats in the available parent-child pairs was 14. Thirty-seven individuals had no family history of HD, with de novo expansion confirmed in three cases.

Novel mutations at the HTT locus may not be rare in India. A lack of family history should not exclude appropriate testing. The prevalence of IA and incidence of de novo expansions suggest that there may be a reservoir of alleles prone to expansion.

Cerebellar ataxias are a heterogeneous group of disorders clinically manifest as impaired coordination during a voluntary motor task resulting from cortico-cerebellar brain network dysfunction, resulting in multiple motor systems including speech, upper limb dexterous movement and gait. Objective assessment of these dysfunctional motor domains provides vital clues in assessing the underlying pathophysiology.

In this study, speech, upper limb kinematics and gait were studied using acoustic software (Praat), upper limb robot (KINARM) and gait carpet (Zeno Walkway with PKMAS). Clinical assessment was conducted using the Scale for the Assessment and Rating of Ataxia (SARA).

In speech analysis, ataxia patients had slower and variable ‘tuh’ syllable repetition performance than healthy controls. In KINARM reaching tasks, ataxia patients displayed less accuracy and efficacy as measured by endpoint error (EE) and mean perpendicular error, along with slower mean and peak velocity of arm movements, prolonged reaction time and increased inter-trial variability. Moreover, there were more EEs while applying load during arm movement. Gait analysis revealed reduced cadence, reduced stride velocity, reduced step length, longer time in the double support phase and increased variability of step length, stride velocity, double support percentage and gait cycle time.

The study highlights the critical role played by the cerebellum during movement execution and has paved the way for more comprehensive future studies on degenerative cerebellar ataxia, incorporating kinematic measurements in multiple motor domains.

Neuromodulation is emerging as a promising intervention for intractable pain syndromes. Despite heterogeneous outcomes in the literature, motor cortex stimulation (MCS) has proven effective in addressing chronic orofacial pain. Painful trigeminal neuropathy (PTN) is characterized by constant facial pain and somatosensory signs. Refractory cases, unresponsive to medical and surgical therapies, significantly impact quality of life and pose socioeconomic challenges. This article presents a retrospective case series of five MCS patients who were treated for refractory PTN in Atlantic Canada.

Since 2021, eight cases of refractory PTN from Atlantic Canada have been recruited. Demographic and clinical characteristics were collected, with primary and secondary outcomes respectively defined as a 50% Visual Analogue Scale (VAS) reduction and a 60% reduction in morphine equivalent dose per day (MED, mg/day) at 12 months post-operation. Pain intensity was assessed preoperatively and at 6- and 12-month follow-ups, along with eating habits, return to work, and global satisfaction.

Five patients with refractory PTN were implanted with MCS, all of whom achieved the primary and secondary outcomes. Preoperatively, mean VAS was 8.4 ± 1.0, reduced to 2.0 ± 1.1 at 12 months post-MCS, corresponding to a 77 ± 13% pain reduction. Average MED/day was reduced by 93 ± 13%, with 60% of participants narcotic-free at 12 months and 80% at 18 months. There were no immediate or delayed complications related to the MCS procedure.

MCS exhibits significant potential for long-term pain relief and reducing opioid consumption in refractory trigeminal pain, emphasizing the necessity for large national multicenter trials.

Movement disorders (Parkinson’s disease, essential tremor, dystonia) are debilitating, progressive conditions that profoundly impact patients’ quality of life. Surgical therapies, such as deep brain stimulation (DBS) can provide tremendous relief to patients but remain costly and, therefore, limited in availability. It is critical to understand regional barriers to accessing this service to improve access for all patients who may benefit from it.

This is a mixed methods survey of stakeholders (patients/family members, advocacy groups, family physicians, neurologists, neurosurgeons) assessing perceived barriers to DBS for movement disorders. Closed and open-ended questions were used. Descriptive statistics were used to highlight regions of Canada where perceived access is poor and to identify barriers to access.

A total of 220 responses were recorded (12 neurosurgeons, 22 neurologists, 30 family physicians, 153 patients and caregivers and 3 advocacy group personnel). Themes included limited resources/centralization of resources, education, burdensome referral patterns and personal patient factors. Barriers included costs associated with travel, waitlists, lack of specific resources and poor understanding of movement disorders, DBS indications and referral pathways.

A number of barriers to access to DBS have been identified, related to geography and centralization of services, referrals and need for further education of indications and safety. The use of virtual care, centralized referral pathways and further research to determine the true prevalence of candidates for this therapy are required to improve access to DBS for movement disorders in Canada.

C-reactive protein (CRP) level in blood is a standard marker for systemic inflammation. Inflammation is central in chronic subdural hematoma (CSDH) pathophysiology, and inflammatory biomarkers may hold clinical potential in assessing the level of inflammation induced by a CSDH. This study explores the role of CRP in patients with CSDH by (1) measuring systemic and subdural CRP levels, (2) investigating CRP as a potential predictor for recurrent CSDH and (3) comparing CRP levels between the first and second operations in patients with CSDH recurrence.

CRP levels were measured both in systemic blood and subdural fluid from adult CSDH patients. Recurrence rate and mortality within 90 days were recorded. In total, 111 patients were included, of whom 25 were operated on for CSDH recurrence.

Systemic CRP levels (2.54 mg/L (1.40–9.75)) were higher than subdural levels (2.09 mg/L [0.99–5.22]) (p < 0.0001) but within the clinically defined normal CRP range of < 3 mg/L. Neither systemic nor subdural CRP levels could predict recurrence. Both systemic and subdural CRP levels in recurrent CSDH patients were higher at the time of the second surgery compared to the first surgery (psystemic = 0.004 and psubdural < 0.0001).

This is the first study to establish a correlation between systemic and subdural CRP levels in CSDH patients. The increased levels of CRP at the time of the second surgery may demonstrate a constantly evolving inflammatory process toward the development of a recurrence.

Lingual seizures are rare hyperkinetic tongue movements with significant clinical implications due to their epileptogenic origin. Despite their diagnostic value, these seizures are often underrecognized, particularly when electroencephalographic (EEG) findings are inconclusive. This study aims to characterize their clinical features, EEG patterns, imaging findings and underlying causes, emphasizing the need for increased awareness and improved diagnosis.

A retrospective review identified patients with isolated lingual seizures or those with additional motor involvement. Data on demographics, seizure characteristics, EEG findings, imaging results and underlying causes were collected and analyzed. Seizures were classified based on the International League Against Epilepsy (ILAE) 2017 framework to refine their clinical and diagnostic profiles.

Thirteen patients were identified: 11 with focal-aware and 1 with focal-unaware seizures. Seven had epilepsia partialis continua, and five experienced frequent seizures. Seizure involvement was limited to the tongue in four cases, extended to cranial muscles in seven and affected the tongue, cranial and extremity muscles in two. Significant ictal EEG findings were noted in only three patients with extensive motor involvement. However, nine patients had acute cerebral lesions, associated with glial tumors, encephalitis, chronic gliosis or cortical hemorrhage.

This study provides a detailed characterization of lingual seizures, highlighting their clinical, electrophysiological and imaging features. Given their rarity and underdiagnosis, our findings offer valuable guidance for clinicians, underscoring the importance of improved recognition and diagnostic strategies for this distinct seizure type.

Levetiracetam (LEV) is an antiseizure medication (ASM) used as a second line after benzodiazepines for status epilepticus treatment. Current literature lacks direct head-to-head comparisons between different LEV loading dose strategies, leading to uncertainty about superior dosing methods and thus clinical practice variations.

A retrospective cohort study was designed to compare efficacy and safety of low (<30 mg/kg) versus high (≥30 mg/kg) weight-based LEV loading doses in adults with benzodiazepine-refractory status epilepticus (BRSE). The primary outcome of this study was termination of BRSE. No requirement for additional ASM after LEV was a surrogate for BRSE termination. Secondary endpoints included endotracheal intubation, intensive care unit (ICU) admission, 30-day all-cause mortality and adverse drug reactions. Statistical analysis included discrete and inferential statistics, including logistic regression and win-ratio analysis, to control for potential confounding variables.

Of the 106 patients included in this study, 54 (51%) did not require additional ASM after LEV, thereby achieving seizure termination. There was a higher proportion of patients with seizure termination in the higher weight-based dosing group as compared to the lower weight-based group (66% vs 40%, respectively; aOR 3.07; 95% CI: 1.36–7.21). There were lower rates for endotracheal intubation, ICU admission and all-cause mortality in the higher dosing group. Adverse events were comparable between the both groups.

LEV’s high weight-based loading dose strategy (≥30 mg/kg) is more effective in the termination of BRSE as compared to the lower weight-based loading dose strategy (<30 mg/kg).

Brain injury related to hypoxic-ischemic insults post-cardiac arrest is a highly morbid and often fatal condition for which neuroprognostication remains challenging. There has been a significant increase in studies assessing the accuracy of multimodal approaches in predicting poor neurological outcomes post-cardiac arrest, and contemporary guidelines recommend this approach. We conducted a systematic review to assess multimodal versus unimodal approaches in neuroprognostication for predicting a poor neurological outcome for adult post-cardiac arrest patients at hospital discharge or beyond.

PRISMA methodological standards were followed. MEDLINE, EMBASE and CINAHL were searched from inception until January 18, 2024, with no restrictions. Abstract and full-text review was completed in duplicate. Original studies assessing the prognostic accuracy (specificity and false positive rate [FPR]) of multimodal compared with unimodal approaches were included. The risk of bias was assessed using the QUIPS tool. Data were extracted in duplicate.

Of 791 abstracts, 12 studies were included. The FPR in predicting poor neurological outcomes ranged from 0% to 5% using a multimodal approach compared to 0% to 31% with a unimodal test. The risk of bias was moderate to high for most components.

A multimodal approach may improve the FPR in predicting poor neurological outcomes of post-cardiac arrest patients.