Brown, Robert

Background: Seizures are a known complication of ischemic stroke. Some studies have reported a higher risk of post-stroke seizure with cardioembolic strokes, whereas others have not. The risk of post-stroke seizure for different stroke mechanisms is unclear. Objective: To compare different stroke etiologies and the risk of post-stroke seizure in a population-based study. Methods: Utilizing the Rochester Epidemiology Project medical records linkage system, we ascertained all first ischemic strokes occurring among Rochester, MN residents from 1990-1994, and followed the patients in the comprehensive medical record through March 2014 for occurrence of seizure. TOAST stroke subtype classification was determined by a consensus of cerebrovascular neurologists. New post-stroke seizure was identified by physician diagnosis and/or EEG report. Patients with a seizure before the index stroke were not included. Pre-morbid stroke risk factors were recorded. Associations between seizure after index ischemic stroke as outcome and other variables of interest were assessed using univariate logistic regression. Results: A total of 490 patients met inclusion criteria, with median follow-up of 6.5 years. Out of 490 patients, 35 had new onset seizures (7.1%). Median age was significantly lower at index stroke for patients with seizures (73 v. 77 years, p=0.017). The most common TOAST stroke subtype was cryptogenic (46.8%) followed by cardioembolic (24.9%). There was no significant difference in TOAST stroke subtypes between patients with post-stroke seizure and those without (p=0.35). There was also no difference between the two groups when comparing combined cardioembolic and large-vessel to small-vessel (p=0.28) or cryptogenic to small-vessel (p=0.9) mechanisms. There was also no difference in pre-morbid stroke risk factors between the two groups, including hypertension (p=0.22), total cholesterol (p=0.95), type 2 diabetes mellitus (p=0.13), tobacco use (p=0.27), atrial fibrillation (p=0.9), or previous myocardial infarction (p=0.67). Conclusion: This study suggests that the long-term risk of post-stroke seizures does not differ by ischemic stroke etiology.

Introduction: Mortality in patients with unruptured intracranial aneurysm (UIA) is significantly higher than the general population. However a minority of the deaths are due to subarachnoid hemorrhage. Hypothesis: There are differential characteristics of patients that might predict specific causes of death that would be informative in counseling patients about aneurysm risk. Methods: 4059 patients with UIA who were enrolled prospectively between 1991 and 1998 were followed by 61 medical centers in North America, Canada, and Europe. Patients have at least one UIA, which may or may not be symptomatic. Patients were Rankin grade 1 or 2 at enrollment. Patients were followed annually from enrollment to 2007. For patients who died a death certificate search was done and information was requested from local physicians and other contacts. A National Death Index search in 2008 determined cases who died and cause of death. Foreign centers also did a national search where possible. Patients who died before 30 days post treatment or lost to follow up before 30 days post enrollment were excluded. Results: Twenty-five percent of patients died during follow-up. The life expectancy was significantly less than age-, sex-, and country-matched expected estimates. Among the total of 4004 patients with UIA who survived 30 days after enrollment, 2331 were treated and 1673 were not. There were 965 deaths after 30 days after treatment, of which 320 died from vascular disease (252 died from non-SAH vascular disease), 114 died from respiratory tract disease, 255 died from cancer, and the rest died of other or unknown reasons. Predictors of SAH death were aneurysm size, site, age and convulsive disorders at enrollment. Factors related to vascular death were UIA treatment, age, gender, race, hypertension, Rankin at discharge and diminishing influence of aneurysm characteristics over time. Respiratory deaths were related to treatment, race, smoking, age, initial Rankin and presentation with convulsive disorder. Cancer deaths were related to gender, race, smoking and age. Conclusions: In patients with UIA, an assessment of risk for death underscores the importance of age, race and gender and several modifiable risk factors. Patient management should include not only aneurysm rupture prevention but also modification of smoking and hypertension.

Background: Causative Classification of Stroke (CCS) system is a novel, web-based, and fully-computerized algorithm that integrates clinical, diagnostic, and etiologic stroke characteristics in an evidence-based manner (available at http://ccs.mgh.harvard.edu ) and provides in a given patient both phenotypic subtypes where abnormal evaluation findings are simply organized in major etiologic categories and causative subtypes where abnormal evaluation findings are filtered through a decision making process to identify the most likely cause of stroke. In this study, we sought to identify the concordance between phenotypic and causative CCS subtypes in the NINDS Stroke Genetics Network (SiGN). Methods: A total of 24 adjudicators from 15 US and European sites certified in CCS retrospectively determined CCS subtypes through chart review in 7134 patients. The CCS software provided causative subtypes in 3 confidence levels as “evident”, “probable” or “possible” based on the weight of causal evidence. We estimated how often CCS classified a given major abnormal evaluation finding as the causative stroke mechanism. Results: CCS assigned 55% of patients with the phenotype of moderate-to-severe atherosclerotic stenosis into the causative category of “evident large artery atherosclerosis”. Likewise, 50% of patients with a major cardiac source (such as atrial fibrillation) were classified into “evident cardio-aortic embolism”, and 74% of those with imaging evidence of a typical lacunar infarct into “evident small artery occlusion”. In 20% to 30% of patients, phenotypic and causative categories were the same but the causative subtype was assigned with a lower level of confidence. Six to 20% of patients with a given phenotypic feature were classified into a different causative category. Failure to investigate for other subtypes in the presence of a positive test finding and the presence of multiple competing etiologies were key contributors to the observed disconcordance between phenotypic and causative subtypes. Conclusions: Our findings show that the presence of a major abnormality in stroke evaluation does not necessarily mean that it is always the cause. The ability of CCS system to discriminate between phenotypic and causative characteristics of stroke etiology provides the opportunity to refine stroke phenotypes for use in research studies.

Introduction: Quality of life changes can occur following procedural interventions and subarachnoid hemorrhage in unruptured intracranial aneurysms (UIA). The International Study of Unruptured Intracranial Aneurysms conducted quality of life assessment using the Mini-Mental State Exam, Rankin Score, and Barthel Index at baseline and the Telephone Interview Cognitive Status Exam (TICS), Rankin Score, and Barthel Index at follow-up. Hypothesis: The purpose of this analysis was to compare the 1 year and 5 year outcome in the treatment cohorts (surgery and endovascular) with those of the untreated subgroup. Methods: Patients were subdivided into the initial treated and untreated cohorts based upon observation or treatment practices in 61 centers from 1991-1998. 1691 patients were in the observational cohort and 2388 in the treated cohort. The cohorts were followed annually with measures of neurological status, Rankin Scale, Barthel Index and cognition (TICS). Outcomes were determined prospectively. Comparison of outcomes was done using continuous and categorical data. Covariate adjustment was done using general linear models. Stratified analysis was done by Rankin Score at the time of follow-up. Results: The percent of patients with a Barthel Index score of less than 60 at 1 year in the cohort was 9.4% (treated patients, 9.7%; untreated patients, 9.2%). The percent of patients at year 1 with a score of greater than 90 was 87.6%, 87.4% for treated patients and 87.8% for untreated patients. The percent of patients with a Barthel Index score of less than 60 at 5 years in the cohort was 41.4% (treated patients, 41.4%; untreated patients, 41.4%). The percent of patients at year 5 with a score of greater than 90 was 56.3%, 56.1% for treated patients and 56.5% for untreated patients. TICS and Barthel Index scores were significantly associated with each other for patients with Rankin Scores 0-2 (P<0.0001). This was seen at both year 1 and year 5 follow-up, but not for patients with Rankin Score 3-5. At both 1 year and 5 year follow-up, after controlling for Rankin Score, the distribution of Barthel Index scores of untreated patients and treated patients did not significantly differ. At both the 1 year follow-up, baseline Rankin Score, TICS and follow-up Rankin Score were significant predictors of Barthel Score (P<0.0001). At 5 years, only the follow-up Rankin Score was associated with Barthel Score (P<0.0001). Conclusions: Barthel Index Score decreased over time, but does not differ with treatment. The Rankin Score was the main predictor at follow-up of Barthel Index Score distribution.