A Computerized Algorithm for Etiologic Classification of Ischemic Stroke

Abstract

Background and Purpose-The SSS-TOAST is an evidence-based classification algorithm for acute ischemic stroke designed to determine the most likely etiology in the presence of multiple competing mechanisms. In this article, we present an automated version of the SSS-TOAST, the Causative Classification System (CCS), to facilitate its utility in multicenter settings. Methods-The CCS is a web-based system that consists of questionnaire-style classification scheme for ischemic stroke (http://ccs.martinos.org). Data entry is provided via checkboxes indicating results of clinical and diagnostic evaluations. The automated algorithm reports the stroke subtype and a description of the classification rationale. We evaluated the reliability of the system via assessment of 50 consecutive patients with ischemic stroke by 5 neurologists from 4 academic stroke centers. Results-The kappa value for inter-examiner agreement was 0.86 (95% CI, 0.81 to 0.91) for the 5-item CCS (large artery atherosclerosis, cardio-aortic embolism, small artery occlusion, other causes, and undetermined causes), 0.85 (95% CI, 0.80 to 0.89) with the undetermined group broken into cryptogenic embolism, other cryptogenic, incomplete evaluation, and unclassified groups (8-item CCS), and 0.80 (95% CI, 0.76 to 0.83) for a 16-item breakdown in which diagnoses were stratified by the level of confidence. The intra-examiner reliability was 0.90 (0.75-1.00) for 5-item, 0.87 (0.73-1.00) for 8-item, and 0.86 (0.75-0.97) for 16-item CCS subtypes. Conclusions-The web-based CCS allows rapid analysis of patient data with excellent intra-and inter-examiner reliability, suggesting a potential utility in improving the fidelity of stroke classification in multicenter trials or research databases in which accurate subtyping is critical.

Mechanisms and treatment of ischaemic stroke—insights from genetic associations

“…To address these difficulties, modifications to the TOAST system have been developed, including the ASCO (Atherosclerosis, Small-vessel disease, Cardiac source, Other cause) system, 61 and the web-based Causative Classification of Stroke (CCS), which is specifically recommended for genetic studies. 62 Comparisons of these systems have generally shown good agreement, 63,64 but future studies will reveal any differences in their ability to detect genome-wide associations.…”

Irregularly shaped lacunar infarction: risk factors and clinical significance

“…The identified infarcts had a diameter of less than 20 mm (as determined by magnetic resonance imaging [MRI]) and were categorized as small vessel occlusions, based on the Classification of Stroke System 6 . Patients who underwent thrombolytic therapy, pa tients with previous physical disabilities, and patients who could not be followed up were excluded from the study.…”

Joinville stroke biobank: study protocol and first year’s results

“…Stroke confirmation and diagnosis were performed as previously reported 9 . In brief, the phenotype of each stroke patient 14,15 . Patients with IS of undetermined cause due to negative investigation or cryptogenic stroke were classified according to the Embolic Strokes of Undetermined Source international work group 16 .…”

“…After 2012, the CCS criteria for phenotyping IS patients were also employed. The neurologists of all cities in the contributing sites were trained by stroke neurologists from the Joinville Stroke Registry using the platform available on the CCS website 15 . After the TOAST diagnosis, the clinical history, physical examination findings and the results of diagnostic work-up were reviewed for determining the CCS classification.…”