CONDITIONS THAT MIMIC STROKE IN THE EMERGENCY DEPARTMENT - IMPLICATIONS FOR ACUTE STROKE TRIALS

Objective: To determine if any clinical variables allow early discrimi nation between stroke and other conditions presenting with a strokelik e picture. Background: New therapeutic modalities for the treatment of acute ischemic stroke are under active investigation. Many of these t reatments have potential adverse effects. It is well known that noncer ebrovascular conditions can present with a clinical picture mimicking stroke, so early accurate differentiation of such ''mimics'' from true stroke is essential. Methods: Consecutive patients who presented to t he emergency department with an initial diagnosis of stroke between Ja nuary 1990 and January 1992 were evaluated. Chart review allowed these patients to be classified into two final diagnostic groups: stroke mi mic and true stroke. Logistic regression was used to estimate the effe cts of predictor variables measured at initial evaluation on the final diagnosis. Results: There were 411 patients initially diagnosed as ha ving stroke. Of these, 78 patients (19%) were eventually found to have mimics, the majority comprising postictal states, systemic infections , tumors, and toxic-metabolic disturbances. Univariate analysis showed that decreased level of consciousness and normal eye movements increa sed the odds of mimic, while abnormal visual fields, diastolic blood p ressure greater than 90 mm Hg, atrial fibrillation on electrocardiogra m, and history of angina decreased the odds of mimic. Multivariate ana lysis showed that decreased consciousness increased, while history of angina decreased, the odds of mimic. Sensitivity of this model for pre dicting mimics was only 21% while specificity was 96%. Conclusion: For the neurologist faced with an immediate decision as to whether to ran domize a patient with probable stroke to an acute treatment protocol, these findings have some usefulness but mandate further research into conditions that mimic stroke in the emergency department.