Clinical Significance of Isolated Atypical Transient Symptoms in a Cohort With Transient Ischemic Attack.

Background And Purpose: Contrary to typical transient symptoms (TS), atypical TS, such as partial sensory deficit, dysarthria, vertigo/unsteadiness, unusual cortical visual deficit, and diplopia, are not usually classified as symptoms of transient ischemic attack when they occur in isolation, and their clinical relevance is frequently denied.

Methods: Consecutive patients with recent TS admitted in our transient ischemic attack clinic (2003-2008) had systematic brain, arterial, and cardiac investigations. We compared the prevalence of recent infarction on brain imaging, major investigational findings (symptomatic intracranial or extracranial atherosclerotic stenosis ≥50%, cervical arterial dissection, and major source of cardiac embolism), and 1-year risk of major vascular events in patients with isolated typical or atypical TS and nonisolated TS, after exclusion of the main differential diagnoses.

Results: Among 1850 patients with possible or definite ischemic diagnoses, 798 (43.1%) had isolated TS: 621 (33.6%) typical and 177 (9.6%) atypical. Acute infarction on brain imaging was similar in patients with isolated atypical and typical TS but less frequent than in patients with nonisolated TS, observed in 10.0%, 11.5%, and 15.3%, respectively (<0.0001). Major investigational findings were found in 18.1%, 26.4%, and 26.3%, respectively (=0.06). One-year risk of a major vascular events was not significantly different in the 3 groups.

Conclusions: Transient ischemic attack diagnosis should be considered and investigated in patients with isolated atypical TS.