Language discordance as a marker of disparities in cerebrovascular risk and stroke outcomes: A multi-center Canadian study.

Background: Differences in ischemic stroke outcomes occur in those with limited English proficiency. These health disparities might arise when a patient's spoken language is discordant from the primary language utilized by the health system. Language concordance is an understudied concept. We examined whether language concordance is associated with differences in vascular risk or post-stroke functional outcomes, depression, obstructive sleep apnea and cognitive impairment. Methods: This was a multi-center observational cross-sectional cohort study. Patients with ischemic stroke/transient ischemic attack (TIA) were consecutively recruited across eight regional stroke centers in Ontario, Canada (2012 - 2018). Participants were language concordant (LC) if they spoke English as their native language, ESL if they used English as a second language, or language discordant (LD) if non-English speaking and requiring translation. Results: 8156 screened patients. 6,556 met inclusion criteria: 5067 LC, 1207 ESL and 282 LD. Compared to LC patients: (i) ESL had increased odds of diabetes (OR = 1.28, p = 0.002), dyslipidemia (OR = 1.20, p = 0.007), and hypertension (OR = 1.37, p<0.001) (ii) LD speaking patients had an increased odds of having dyslipidemia (OR = 1.35, p = 0.034), hypertension (OR = 1.37, p<0.001), and worse functional outcome (OR = 1.66, p<0.0001). ESL (OR = 1.88, p<0.0001) and LD (OR = 1.71, p<0.0001) patients were more likely to have lower cognitive scores. No associations were noted with obstructive sleep apnea (OSA) or depression. Conclusions: Measuring language concordance in stroke/TIA reveals differences in neurovascular risk and functional outcome among patients with limited proficiency in the primary language of their health system. Lower cognitive scores must be interpreted with caution as they may be influenced by translation and/or greater vascular risk. Language concordance is a simple, readily available marker to identify those at risk of worse functional outcome. Stroke systems and practitioners must now study why these differences exist and devise adaptive care models, treatments and education strategies to mitigate barriers influenced by language discordance.

Methods for Improving Screening for Vascular Cognitive Impairment Using the Montreal Cognitive Assessment.

BACKGROUND: Vascular cognitive impairment (VCI) post-stroke is frequent but may go undetected, which highlights the need to better screen cognitive functioning following a stroke. AIM: We examined the clinical utility of the Montreal Cognitive Assessment (MoCA) in detecting cognitive impairment against a gold-standard neuropsychological battery. METHODS: We assessed cognitive status with a comprehensive battery of neuropsychological tests in 161 individuals who were at least 3-months post-stroke. We used receiver operating characteristic (ROC) curves to identify two cut points for the MoCA to maximize sensitivity and specificity at a minimum 90% threshold. We examined the utility of the Symbol Digit Modalities Test, a processing speed measure, to determine whether this additional metric would improve classification relative to the MoCA total score alone. RESULTS: Using two cut points, 27% of participants scored ≤ 23 and were classified as high probability of cognitive impairment (sensitivity 92%), and 24% of participants scored ≥ 28 and were classified as low probability of cognitive impairment (specificity 91%). The remaining 48% of participants scored from 24 to 27 and were classified as indeterminate probability of cognitive impairment. The addition of a processing speed measure improved classification for the indeterminate group by correctly identifying 65% of these individuals, for an overall classification accuracy of 79%. CONCLUSIONS: The utility of the MoCA in detecting cognitive impairment post-stroke is improved when using a three-category approach. The addition of a processing speed measure provides a practical and efficient method to increase confidence in the determined outcome while minimally extending the screening routine for VCI.

Use of Geospatial Modeling to Evaluate the Impact of Telestroke on Access to Stroke Thrombolysis in Ontario.

BACKGROUND: The treatment of acute ischemic stroke in Ontario is coordinated through a network of stroke centers, supplemented by emergency telemedicine consultations to nonstroke centers through the Ontario Telemedicine Network's province-wide Telestroke program. Using geoinformatics, we sought to evaluate the overall impact of Telestroke on access to stroke thrombolysis in Ontario. METHODS: Ontario population data (census) were used to overlay polygons created by Service Area Analysis using ArcGIS 10.1. Service areas were divided into predefined driving times toward the nearest stroke center. Centers were compared after they were categorized as being able to administer stroke thrombolysis either independently or through the Telestroke program. RESULTS: Of the 12,857,821 people living in Ontario in 2011, 99.83% had timely access to stroke thrombolysis, leaving 21,829 people, exclusively within Northern Ontario, without access. Of the population, 71.86% was within a 30-minute drive of a regional or district stroke center, increasing to 91.28% when the Telestroke program was included, for an additional 2,501,121 people. Of the population, 1.85% had access to stroke thrombolysis only through the extended time window (between 3 and 4.5 hours), increasing to 3.86% with Telestroke, for an additional 258,618 people. CONCLUSION: The vast majority of people in Ontario have access to stroke thrombolysis. The provincial Telestroke program improves timeliness of access for those living in Southern Ontario, although some remote rural and Northern communities remain without access. Geoinformatics may likewise prove useful in coordinating provincial access to endovascular thrombectomy.

Validating a Pragmatic Approach to Cognitive Screening in Stroke Prevention Clinics Using the Montreal Cognitive Assessment.

BACKGROUND AND PURPOSE: The Montreal Cognitive Assessment (MoCA) is used commonly to identify cognitive impairment (CI), but there are multiple published cut points for normal and abnormal. We seek to validate a pragmatic approach to screening for moderate-severe CI, by classifying patients into high-, intermediate-, and low-risk categories. METHODS: A total of 390 participants attending an academic Stroke Prevention Clinic completed the MoCA and more detailed neuropsychological testing. Between April 23, 2012 and April 30, 2014, all consecutive new referrals to the regional Stroke Prevention Clinic who were English-speaking, not severely aphasic, and could see and write well enough to complete neuropsychological testing were assessed for inclusion, and consenting patients were enrolled. CI was defined as ≥2 SDs below normal for age and education on at least 2 cognitive subtests. A single cut point for CI was compared with 2 cut points (high sensitivity and high specificity) generated using receiver operator characteristic and area under the curve analyses. The intermediate-risk group contained those scoring between the 2 cut points. RESULTS: Thirty-four percent of participants had a symptomatic or silent stroke, 34% were seen for possible or probable transient ischemic attack, and 32% were diagnosed with other vascular or nonvascular conditions. Using a single cut point, sensitivity and specificity were optimal with MoCA ≤22, (sensitivity=60.4%, specificity=89.9%, area under the curve=0.801, positive predictive value=48.5%, negative predictive value=93.5%, positive likelihood ratio=6, and negative likelihood ratio=0.4). Using 2 cut points, sensitivity was optimal with MoCA ≥28 (sensitivity=96.2%, negative predictive value =97.6%, and negative likelihood ratio=1.27), and specificity was optimal with MoCA ≤22 (specificity=89.9%, positive predictive value=48.5%, and positive likelihood ratio=6). CONCLUSIONS: Stratifying participants into 3 categories facilitates the identification of a homogenous group at low risk for CI, as well as 2 other groups with intermediate and higher risk. This approach could facilitate clinical care pathways and patient selection for research.

A prospective cohort study of patients with transient ischemic attack to identify high-risk clinical characteristics.

BACKGROUND AND PURPOSE: The occurrence of a transient ischemic attack (TIA) increases an individual's risk for subsequent stroke. The objectives of this study were to determine clinical features of patients with TIA associated with impending (≤7 days) stroke and to develop a clinical prediction score for impending stroke. METHODS: We conducted a prospective cohort study at 8 Canadian emergency departments for 5 years. We enrolled patients with a new TIA. Our outcome was subsequent stroke within 7 days of TIA diagnosis. RESULTS: We prospectively enrolled 3906 patients, of which 86 (2.2%) experienced a stroke within 7 days. Clinical features strongly correlated with having an impending stroke included first-ever TIA, language disturbance, longer duration, weakness, gait disturbance, elevated blood pressure, atrial fibrillation on ECG, infarction on computed tomography, and elevated blood glucose. Variables less associated with having an impending stroke included vertigo, lightheadedness, and visual loss. From this cohort, we derived the Canadian TIA Score which identifies the risk of subsequent stroke≤7 days and consists of 13 variables. This model has good discrimination with a c-statistic of 0.77 (95% confidence interval, 0.73-0.82). CONCLUSIONS: Patients with TIA with their first TIA, language disturbance, duration of symptoms≥10 minutes, gait disturbance, atrial fibrillation, infarction on computed tomography, elevated platelets or glucose, unilateral weakness, history of carotid stenosis, and elevated diastolic blood pressure are at higher risk for an impending stroke. Patients with vertigo and no high-risk features are at low risk. The Canadian TIA Score quantifies the impending stroke risk following TIA.

A citywide prehospital protocol increases access to stroke thrombolysis in Toronto.

BACKGROUND AND PURPOSE: Intravenous tissue plasminogen activator for ischemic stroke is approved for eligible patients who can be treated within a 3-hour window, but treatment rates remain disappointingly low, often <5%. To improve rapid access to stroke thrombolysis in Toronto, Canada, a citywide prehospital acute stroke activation protocol was implemented by the provincial government to transport acute stroke patients directly to one of 3 regional stroke centers, bypassing local hospitals. This comprised a paramedic screening tool, ambulance destination decision rule, and formal memorandum of understanding of system stakeholders. This report describes the initial impact of the activation protocol at our regional stroke center. METHODS: We compared consecutive patients with stroke arriving to our stroke center during the first 4 months of this new triage protocol (February 14 to June 14, 2005) versus the same 4-month period in 2004. RESULTS: The protocol resulted in an immediate doubling in the number of patients with acute stroke arriving to our regional stroke center within 2.5 hours of symptom onset. We observed a 4-fold increase in patients who were eligible for and treated with tissue plasminogen activator. The tissue plasminogen activator treatment rate for ischemic stroke patients increased from 9.5% to 23.4% (P=0.01), and one in 2 patients with ischemic stroke arriving within 2.5 hours received thrombolysis during this period (one in 5 of patients with ischemic stroke overall). The median onset-to-needle time for tissue plasminogen activator-treated patients was significantly reduced. Many implementation challenges were identified and addressed. CONCLUSIONS: This prehospital triage was immediately successful in improving tissue plasminogen activator access for patients with ischemic stroke, enabling our center to achieve one of the highest tissue plasminogen activator treatment rates in North America and underscoring the need for coordinated systems of acute stroke care. Sustainability of such an initiative will be dependent on interdisciplinary teamwork, ongoing paramedic training, adequate hospital staffing, bed availability, and repatriation agreements with community hospitals.