Is This Patient Having a Stroke?

Abstract

CONTEXT: Patients suspected of having a stroke or transient ischemic attack require accurate assessment for appropriate acute treatment and use of secondary preventive interventions. OBJECTIVE: To update a 1994 systematic review of the accuracy and reliability of symptoms and findings on neurological examination for the evaluation of patients with suspected stroke or transient ischemic attack. DATA SOURCES: We identified potential articles dated between 1994 and 2005 by multiple search strategies of the MEDLINE database and review of article and textbook bibliographies along with private collections. STUDY SELECTION: Selected articles provided primary data or appropriate summary statistics of the accuracy and/or reliability of the history or physical examination for diagnosis or short-term prognosis of patients with neurological signs prompting a consideration of stroke. Articles addressing accuracy also needed to provide a final diagnosis following neuroimaging and all relevant laboratory tests. DATA EXTRACTION: The authors reviewed and abstracted data for estimating sensitivities, specificities, positive and negative likelihood ratios (LRs). Reliability assessment was based on reported kappa (kappa) statistics or intraclass correlation coefficients as appropriate. DATA SYNTHESIS: The prior probability of a stroke among patients with neurologically relevant symptoms is 10%. Based on studies using modern neuroimaging, the presence of acute facial paresis, arm drift, or abnormal speech increases the likelihood of stroke (LR of > or =1 finding = 5.5; 95% CI, 3.3-9.1), while the absence of all 3 decreases the odds (LR of 0 findings = 0.39; 95% CI, 0.25-0.61). The accurate determination of stroke subtype requires neuroimaging to distinguish ischemic from hemorrhagic stroke. Early mortality increases among those with any combination of impaired consciousness, hemiplegia, and conjugate gaze palsy (LR of > or =1 finding = 1.8; 95% CI, 1.2-2.8 and LR of 0 findings = 0.36; 95% CI, 0.13-1.0). Symptoms associated with high agreement for the diagnosis of stroke or transient ischemic attack vs no vascular event are a sudden change in speech, visual loss, diplopia, numbness or tingling, paralysis or weakness, and non-orthostatic dizziness (kappa = 0.60; 95% CI, 0.52-0.68). The reliabilities of individual neurological findings vary from slight to almost perfect, but can be improved with standardized scoring systems such as the National Institutes of Health Stroke Scale. Based on examination findings, stroke vascular distribution can be determined with moderate to good reliability (kappa = 0.54; 95% CI, 0.39-0.68). CONCLUSIONS: The history and clinical findings provide the basis for evaluating patients with possible stroke and choosing appropriate treatments. Focusing on 3 findings (acute facial paresis, arm drift, or abnormal speech) might improve diagnostic accuracy and reliability.