Spinal muscular atrophy (SMA) is a leading genetic cause of infant death and represents a significant burden of care. An improved understanding of the epidemiology of SMA in Canada may help inform strategies to improve the standard of care for individuals living with SMA.

We employed a multisource approach to estimate the minimal incidence and prevalence of 5q SMA and to gain greater insight into recent clinical practices and treatment trends for the Canadian SMA population. Data sources included the Canadian Paediatric Surveillance Program (CPSP), Canadian Neuromuscular Disease Registry (CNDR), and molecular genetics laboratories in Canada.

The estimated annual minimum incidence of 5q SMA was 4.38, 3.44, and 7.99 cases per 100,000 live births in 2020 and 2021, based on CPSP, CNDR, and molecular genetics laboratories data, respectively, representing approximately 1 in 21,472 births (range 12,516–29,070) in Canada. SMA prevalence was estimated to be 0.85 per 100,000 persons aged 0–79 years. Delay in diagnosis exists across all SMA subtypes. Most common presenting symptoms were delayed milestones, hypotonia, and muscle weakness. Nusinersen was the most common disease-modifying treatment received. Most patients utilized multidisciplinary clinics for management of SMA.

This study provides data on the annual minimum incidence of pediatric 5q SMA in Canada. Recent therapeutic advances and newborn screening have the potential to drastically alter the natural history of SMA. Findings underline the importance of ongoing surveillance of the epidemiology and long-term health outcomes of SMA in the Canadian population.

Status epilepticus (SE) is a neurological emergency characterized by prolonged seizures. However, the incidence of first-episode SE is unclear, as estimates vary greatly among studies. Additionally, SE risk factors have been insufficiently explored. Therefore, the objectives of this study were to estimate the incidence of first-episode SE in Ontario, Canada, and estimate the associations between potential sociodemographic and health-related risk factors and first-episode SE.

We conducted a population-based retrospective cohort study using linked health administrative datasets. We included individuals who completed Canada’s 2006 Census long-form questionnaire, lived in Ontario, were between 18 and 105, and had no history of SE. A Cox proportional hazards regression model was used to estimate the hazard ratios for SE within three years associated with each potential risk factor.

The final sample included 1,301,700 participants, 140 of whom were hospitalized or had an emergency department visit for first-episode SE during follow-up (3.5 per 100,000 person-years). Older age was the only significant sociodemographic SE risk factor (HR = 1.35, 95% CI = 1.33, 1.37), while health-related risk factors included alcohol or drug abuse (HR = 1.05, 95% CI = 1.02, 1.08), brain tumour or cancer (HR = 1.14, 95% CI = 1.12, 1.15), chronic kidney disease (HR = 1.32, 95% CI = 1.29, 1.36), dementia (HR = 1.42, 95% CI = 1.36, 1.48), diabetes (HR = 1.11, 95% CI = 1.09, 1.12), epilepsy or seizures (HR = 1.05, 95% CI = 1.01, 1.09) and stroke (HR = 1.08, 95% CI = 1.05, 1.11).

The estimated incidence of SE in a sample of Ontario residents was 3.5 per 100,000 person-years. Older age and several comorbid conditions were associated with higher first-episode SE risk.

Newborn screening (NBS) identifies infants with severe, early-onset diseases, enabling early diagnosis and treatment. In Canada, decisions regarding disease inclusion in NBS programs occur at the provincial level, which leads to variability in patient care. We aimed to determine whether important differences exist in NBS programs across provinces and territories. Given that spinal muscular atrophy (SMA) is the most recent disease added to NBS programs, we hypothesized that its inclusion would show interprovincial variability and be more likely in provinces already screening for a greater number of diseases.

We conducted a cross-sectional survey of all NBS labs in Canada to understand: 1) what conditions were included in their program; 2) what genetic-based testing was performed and; 3) if SMA was included.

All NBS programs (N = 8) responded to this survey by June 2022. There was a 2.5-fold difference in the number of conditions screened (N = 14 vs N = 36) and a 9-fold difference in the number of conditions screened by gene-based testing. Only nine conditions were common to all provincial NBS programs. NBS for SMA was performed in four provinces at the time of our survey, with BC recently becoming the fifth province to add SMA to their NBS on October 1, 2022. Currently, 72% of Canadian newborns are screened for SMA at birth.

Although healthcare in Canada is universal, its decentralization gives rise to regional differences in NBS programs which creates inequity in the treatment, care, and potential outcomes of affected children across provincial jurisdictions.

To assess cost-effectiveness of late time-window endovascular treatment (EVT) in a clinical trial setting and a “real-world” setting.

Data are from the randomized ESCAPE trial and a prospective cohort study (ESCAPE-LATE). Anterior circulation large vessel occlusion patients presenting > 6 hours from last-known-well were included, whereby collateral status was an inclusion criterion for ESCAPE but not ESCAPE-LATE. A Markov state transition model was built to estimate lifetime costs and quality-adjusted life-years (QALYs) for EVT in addition to best medical care vs. best medical care only in a clinical trial setting (comparing ESCAPE-EVT to ESCAPE control arm patients) and a “real-world” setting (comparing ESCAPE-LATE to ESCAPE control arm patients). We performed an unadjusted analysis, using 90-day modified Rankin Scale(mRS) scores as model input and analysis adjusted for baseline factors. Acceptability of EVT was calculated using upper/lower willingness-to-pay thresholds of 100,000 USD/50,000 USD/QALY.

Two-hundred and forty-nine patients were included (ESCAPE-LATE:n = 200, ESCAPE EVT-arm:n = 29, ESCAPE control-arm:n = 20). Late EVT in addition to best medical care was cost effective in the unadjusted analysis both in the clinical trial and real-world setting, with acceptability 96.6%–99.0%. After adjusting for differences in baseline variables between the groups, late EVT was marginally cost effective in the clinical trial setting (acceptability:49.9%–61.6%), but not the “real-world” setting (acceptability:32.9%–42.6%).

EVT for LVO-patients presenting beyond 6 hours was cost effective in the clinical trial setting and “real-world” setting, although this was largely related to baseline patient differences favoring the “real-world” EVT group. After adjusting for these, EVT benefit was reduced in the trial setting, and absent in the real-world setting.

Up to 30% of patients with Guillain–Barré syndrome require mechanical ventilation and 5% die due to acute complications of mechanical ventilation. There is a considerable group of patients that will need prolonged mechanical ventilation (considered as >14 days) and should be considered for early tracheostomy. The objective of this study is to identify risk factors for prolonged mechanical ventilation.

We prospectively analyzed patients with Guillain–Barré diagnosis with versus without prolonged mechanical ventilation. We considered clinical and electrophysiological characteristics and analyzed factors associated with prolonged mechanical ventilation.

Three hundred and three patients were included; 29% required mechanical ventilation. When comparing the groups, patients with prolonged invasive mechanical ventilation (IMV) have a lower score on the Medical Research Council score (19.5 ± 16.2 vs 27.4 ± 17.5, p = 0.03) and a higher frequency of dysautonomia (42.3% vs 19.4%, p = 0.037), as well as lower amplitudes of the distal compound muscle action potential (CMAP) of the median nerve [0.37 (RIQ 0.07–2.25) vs. 3.9 (RIQ1.2–6.4), p = <0.001] and ulnar nerve [0.37 (RIQ0.0–3.72) vs 1.5 (RIQ0.3–6.6), p = <0.001], and higher frequency of severe axonal damage in these nerves (distal CMAP ≤ 1.0 mV). Through binary logistic regression, severe axonal degeneration of the median nerve is an independent risk factor for prolonged IMV OR 4.9 (95%CI 1.1–21.5) p = 0.03, AUC of 0.774, (95%CI 0.66–0.88), p = < 0.001.

Severe median nerve damage is an independent risk factor for prolonged mechanical ventilation.

Optic nerve hypoplasia (ONH) and septo-optic-pituitary dysplasia (SOD) are neurodevelopmental disorders associated with congenital visual impairment. Our aim was to investigate associations between several ophthalmic and neuroimaging features in patients with ONH/SOD.

A retrospective chart and neuroimaging review was performed in patients with ONH/SOD. Ophthalmic signs (e.g., monocular best-corrected visual acuity [BCVA], nystagmus, and strabismus) and neuroimaging data were extracted and their associations were investigated.

There were 128 patients (70 males) with ONH/SOD who had neuroimaging. Their mean age at the end of the study was 13.2 (SD: 7.5) years. Ophthalmic data were available on 102 patients (58 males). BCVA varied from normal to no light perception. There were statistically significant associations between: (A) Reduced optic nerve or chiasm size on neuroimaging and more severely impaired BCVA and (B) laterality of the reduced optic nerve or chiasm size on neuroimaging and laterality of: (1) The eye with reduced BCVA, (2) small optic disc size, and (3) RAPD, if present (p ≤ 0.0002 each). The presence of symmetrically small optic nerves on MRI was significantly more common in patients with nystagmus than when nystagmus was absent (N = 96, 75% vs. 38.6%, p < 0.0001). The presence of neuronal migration disorders, their type and laterality were not associated with BCVA and laterality of the reduced BCVA.

The functional and structural associations in ONH are consistent with the impaired visual function that results from the hypoplastic anterior visual pathways. However, these associations were not perfectly concordant making prediction of adult BCVA challenging in these patients.

Numerous studies have shown longer pre-hospital and in-hospital workflow times and poorer outcomes in women after acute ischemic stroke (AIS) in general and after endovascular treatment (EVT) in particular. We investigated sex differences in acute stroke care of EVT patients over 5 years in a comprehensive Canadian provincial registry.

Clinical data of all AIS patients who underwent EVT between January 2017 and December 2022 in the province of Saskatchewan were captured in the Canadian OPTIMISE registry and supplemented with patient data from administrative data sources. Patient baseline characteristics, transport time metrics, and technical EVT outcomes between female and male EVT patients were compared.

Three-hundred-three patients underwent EVT between 2017 and 2022: 144 (47.5%) women and 159 (52.5%) men. Women were significantly older (median age 77.5 [interquartile range: 66–85] vs.71 [59–78], p < 0.001), while men had more intracranial internal carotid artery occlusions (48/159 [30.2%] vs. 26/142 [18.3%], p = 0.03). Last-known-well to comprehensive stroke center (CSC)-arrival time (median 232 min [interquartile range 90–432] in women vs. 230 min [90–352] in men), CSC-arrival-to-reperfusion time (median 108 min [88–149] in women vs. 102 min [77–141] in men), reperfusion status (successful reperfusion 106/142 [74.7%] in women vs. 117/158 [74.1%] in men) as well as modified Rankin score at 90 days did not differ significantly. This held true after adjusting for baseline variables in multivariable analyses.

While women undergoing EVT in the province of Saskatchewan were on average older than men, they were treated just as fast and achieved similar technical and clinical outcomes compared to men.

Optic nerve hypoplasia (ONH) and septo-optic-pituitary dysplasia (SOD) are common causes of congenital visual impairment. Our primary aim was to investigate the prevalence of abnormal neuroimaging features in patients with these disorders in Manitoba, Canada, and compare them with published reports.

A retrospective neuroimaging review was performed in patients resident in Manitoba with ONH/SOD.

There were 128 patients (M = 70) with ONH/SOD who had neuroimaging. Their mean age (SD) at the end of the study was 13.2 (7.5) years. Males were significantly more likely to have bilateral ONH and a small optic chiasm size, while females were more likely to have a left ONH and a small left optic chiasm size on neuroimaging (p = 0.049). ONH and small optic chiasm size were seen in most patients on neuroimaging. Absent septum pellucidum was noted in 40%, small pituitary gland size in 28%, neuronal migration disorders (NMD) in 20% (>1 type and bilateral in 13 cases), corpus callosum abnormalities were present in 9%, while olfactory bulbs-tracts and olfactory sulci were absent in 8.6% of cases. Unilateral ONH was not significantly associated with other structural brain abnormalities, while NMD were significantly associated with other midline brain abnormalities including a symmetrically small optic chiasm size.

The prevalence of structural neuroimaging abnormalities in our cohort with ONH/SOD was generally in the same range reported in other studies with corpus callosum abnormalities being relatively less common in our study. Bilateral NMD were relatively common among patients with NMD. The association between sex and ONH laterality requires further study.

Ocrelizumab is an effective anti-CD20 therapy approved for Relapsing Remitting (RRMS) and Primary Progressive Multiple Sclerosis (PPMS). In clinical trials, a proportion of patients developed hypogammaglobulinemia which could contribute to infection risk. This study aimed to identify hypogammaglobulinemia and its risk factors and evaluate potentially associated serious infection risk in a real-world cohort of patients.

All MS patients treated with ocrelizumab in a Quebec City MS clinic from January 2017 to August 2021 were included and detailed patient characteristics were collected by chart review. Levels of immunoglobulins (IgM, IgA and IgG) were assessed prior to each treatment. Serious infection was defined as an infection requiring hospitalization or emergency room treatment. Association between hypogammaglobulinemia and serious infection was analyzed.

A total of 266 patients (average follow-up 2.05 years) were included (87% RRMS). After 6 infusions, 32.8%, 3.5% and 4.2% of patients had at least one IgM, IgA and IgG hypogammaglobulinemia event respectively. Aside from pre-treatment hypogammaglobulinemia, there were no variables associated with on-treatment hypogammaglobulinemia. There was a total of 21 serious infections (3.36 and 12.33 per 100-person-years in RRMS and PPMS). Developing hypogammaglobulinemia during treatment was not associated with serious infection. A regression analysis did not show associations between serious infection and key disease characteristics.

Similar to ocrelizumab extension studies, our cohort demonstrated a significant rate of hypogammaglobulinemia over time, mostly with IgM. No association was found between hypogammaglobulinemia and serious infection.

To describe demographic and clinical characteristics, healthcare resource use, costs, and treatment patterns in three migraine cohorts.

This retrospective observational study using administrative data examined patients with episodic migraine (EM), chronic migraine (CM) (without medication overuse headache [MOH]), and medication overuse headache in Alberta, Canada. Migraine patients were identified between 2012 and 2018 based on ≥ 1 diagnostic codes or triptan prescription. Patients with CM were defined using parameter estimates of a logistic regression model, and MOH was defined as patients with an average of ≥ 15 supply days covered of acute medications. EM was defined as patients without CM or MOH. Study outcomes were summarized using descriptive statistics.

Patients with EM (n = 144,574), CM (n = 27,283), and MOH (n = 11,485) were included. Higher rates of healthcare use and costs were observed for CM (mean [SD] all-cause cost: ($12,693 [40,664]) and MOH ($16,611.5 [$38,748]) versus episodic migraine ($4,251 [$40,637]). Across all cohorts, opioids were the most dispensed acute medication (range across cohorts: 31.7%–89.8%), while antidepressants and anticonvulsants were the most dispensed preventive medication. Preventative medication classes were used by a minority of patients in each cohort, except anticonvulsants, where 50% of medication overuse patients had a dispensation.

Patients with CM and MOH have a greater burden of illness compared to patients with EM. The overutilization of acute medication, particularly opioids, and the underutilization of preventive medications highlight an unmet need to more effectively manage migraine.

Whereas the beneficial effect of antiplatelet therapy for recurrent stroke prevention has been well established, uncertainties remain regarding the optimal antithrombotic regimen for recently symptomatic carotid stenosis. We sought to explore the approaches of stroke physicians to antithrombotic management of patients with symptomatic carotid stenosis.

We employed a qualitative descriptive methodology to explore the decision-making approaches and opinions of physicians regarding antithrombotic regimens for symptomatic carotid stenosis. We conducted semi-structured interviews with a purposive sample of 22 stroke physicians (11 neurologists, 3 geriatricians, 5 interventional-neuroradiologists, and 3 neurosurgeons) from 16 centers on four continents to discuss symptomatic carotid stenosis management. We then conducted thematic analysis on the transcripts.

Important themes revealed from our analysis included limitations of existing clinical trial evidence, competing surgeon versus neurologist/internist preferences, and the choice of antiplatelet therapy while awaiting revascularization. There was a greater concern for adverse events while using multiple antiplatelet agents (e.g., dual-antiplatelet therapy (DAPT)) in patients undergoing carotid endarterectomy compared to carotid artery stenting. Regional variations included more frequent use of single antiplatelet agents among European participants. Areas of uncertainty included antithrombotic management if already on an antiplatelet agent, implications of nonstenotic features of carotid disease, the role of newer antiplatelet agents or anticoagulants, platelet aggregation testing, and timing of DAPT.

Our qualitative findings can help physicians critically examine the rationale underlying their own antithrombotic approaches to symptomatic carotid stenosis. Future clinical trials may wish to accommodate identified variations in practice patterns and areas of uncertainty to better inform clinical practice.

Pathophysiology of levodopa-induced dyskinesia (LID) remains obscure. Increased dopamine metabolism due to prolonged levodopa treatment can exacerbate oxidative damage and neuroinflammatory pathology in Parkinson’s disease (PD). Association of novel peripheral markers with LID severity might provide insight into LID pathomechanisms.

We aimed to study specific peripheral blood inflammatory-oxidative markers in LID patients and investigate their association with clinical severity of LID.

Motor, non-motor and cognitive changes in PD with and without LID compared to healthy-matched controls were identified. Within the same cohort, inflammatory marker (sLAG3, TOLLIP, NLRP3 and IL-1β) levels and antioxidant enzyme activities were determined by ELISA and spectrophotometric methods.

LID patients showed distinctly upregulated TOLLIP, IL-1β levels with significant diminution of antioxidant activity compared to controls. Significant negative association of cognitive markers with oxidative changes was also observed.

To our understanding, this is the first study that indicates the involvement of toll-like receptor-mediated distinct and low-grade inflammatory activation in LID pathophysiology.

Migraine poses a significant burden worldwide; however, there is limited evidence as to the burden in Canada. This study examined the treatment patterns, healthcare resource use (HRU), and costs among newly diagnosed or recurrent patients with migraine in Alberta, Canada, from the time of diagnosis or recurrence.

This retrospective observational study utilized administrative health data from Alberta, Canada. Patients were included in the Total Migraine Cohort if they had: (1) ≥1 International Classification of Diseases diagnostic code for migraine; or (2) ≥1 prescription dispense(s) for triptans from April 1, 2012, to March 31, 2018, with no previous diagnosis or dispensation code from April 1, 2010, to April 1, 2012.

The mean age of the cohort (n = 199,931) was 40.0 years and 72.3% were women. The most common comorbidity was depression (19.7%). In each medication class examined, less than one-third of the cohort was prescribed triptans and fewer than one-fifth was prescribed a preventive. Among patients with ≥1 dispense, the mean rate of opioid prescriptions was 4.61 per patient-year, compared to 2.28 triptan prescriptions per patient-year. Migraine-related HRU accounted for 3%–10% of all use.

Comorbidities and high all-cause HRU were observed among newly diagnosed or recurrent patients with migraine. There is an underutilization of acute and preventive medications in the management of migraine. The high rate of opioid use reinforces the suboptimal management of migraine in Alberta. Migraine management may improve by educating healthcare professionals to optimize treatment strategies.

Carotid artery stenosis causes up to 20% of ischemic strokes. Stenting is used as an alternative to endarterectomy in symptomatic patients. Each commercially available stent offers numerous stent diameters/lengths. Most centers thus carefully match each individual stenosis to a specific stent length/diameter stent size. However, this process can be time-consuming and costly while the relative benefit of a custom stent sizing versus one-size-fits-all approach has not been well evaluated yet. We hypothesized that a ‘one-size-fits-all’ default approach to carotid stenting results in comparable results to a customized approach.

We conducted a descriptive retrospective cohort study on 154 patients who presented to our academic carotid revascularization clinic with symptomatic carotid artery stenosis who underwent carotid artery stenting for peri- and postprocedural carotid artery stenting complications. The primary outcomes were periprocedural (within 24 hours of the procedure) or postprocedural (within 30 days of the procedure) TIA, stroke, or death. The secondary outcome was the estimated degree of stenosis on follow-up ultrasound performed within 6 months of the procedure.

The complication rate within the first 24 hours was 4.5% while that during the first 30 days postprocedure was 6.5%. Age over 80 and degree of stenosis on postprocedural cerebral angiogram were associated with an increased risk of complications. Severe restenosis was reported in 16.8% of patients within 6 months postprocedure.

Our study suggests that using a simplified, one-size-fits-all, approach to carotid stenting results in safe and effective outcomes, suggesting an alternative to simplify a complex medical procedure.