The telestroke mimic (TM)-score: A prediction rule for identifying stroke mimics evaluated in a telestroke network

Background-up to 30% of acute stroke evaluations are deemed stroke mimics (sm). as telestroke consultation expands across the world,increasing numbers of sm patients are likely being evaluated via telestroke. we developed a model to prospectively identify ischemic sms during telestroke evaluation. methods and results-we analyzed 829 consecutive patients from january 2004 to april 2013 in our internal new england-based partners telestroke network for a derivation cohort,and 332 cases for internal validation. external validation was performed on 226 cases from january 2008 to august 2012 in the partners national telestroke network. a predictive score was developed using stepwise logistic regression,and its performance was assessed using receiver-operating characteristic (roc) curve analysis. there were 23% sm in the derivation,24% in the internal,and 22% in external validation cohorts based on final clinical diagnosis. compared to those with ischemic cerebrovascular disease (icvd),sm had lower mean age,fewer vascular risk factors,more frequent prior seizure,and a different profile of presenting symptoms. the telestroke mimic score (tm-score) was based on factors independently associated with sm status including age,medical history (atrial fibrillation,hypertension,seizures),facial weakness,and national institutes of health stroke scale >14. the tm-score performed well on roc curve analysis (derivation cohort auc=0.75,internal validation auc=0.71,external validation auc=0.77). conclusions-sms differ substantially from their icvd counterparts in their vascular risk profiles and other characteristics. decision-support tools based on predictive models,such as our tm score,may help clinicians consider alternate diagnosis and potentially detect sms during complex,time-critical telestroke evaluations. © 2014 the authors.