Factors Associated With Focal Computed Tomographic Perfusion Abnormalities in Supratentorial Transient Ischemic Attacks.

BACKGROUND AND PURPOSE: Computed tomographic perfusion (CTP) is useful in diagnosis of patients with transient focal neurological symptoms. In acute imaging of patients with a suspected transient ischemic attack (TIA), it remains unclear which patients develop focal perfusion abnormalities (FPA), that is, hypoperfusion or hyperperfusion. We aimed at determining independent factors associated with FPA in patients with supratentorial TIAs.

METHODS: We prospectively collected consecutive patients with supratentorial TIAs defined by the traditional time-based definition who underwent CTP within 24 hours of symptom onset. We recorded demographics, risk factors, clinical features, severity, and timing from onset. We documented the Age, Blood Pressure, Clinical Features, Duration, and Diabetes (ABCD2) scores, vascular territories, and presence of relevant arterial pathology. Variables were tested for an association with FPA with univariate and multivariate analyses.

RESULTS: A hundred and ten of 265 patients (42%) with supratentorial TIAs had FPA on CTP. Acute noncontrast computed tomography showed early ischemic lesions in 6%, and acute/subacute magnetic resonance imaging was pathological in 52 of the 109 cases (47.7%) where it was performed. Clinical factors associated with FPA were high-admission National Institutes of Health Stroke Scale (odds ratio [OR], 1.22), right hemispheric TIA (OR, 3.09), and cardioembolic mechanism (OR, 2.19). Persistence of symptoms during CTP (OR, 2.59), shorter duration of TIA (OR, 0.93), major intracranial arterial pathology (OR, 12.5), and extracranial arterial occlusion (OR, 7.44) were also associated with FPA.

CONCLUSIONS: Supratentorial TIAs are often associated with FPA in CTP, even after symptom resolution. FPAs are frequent in severe TIAs and those associated with cardioembolism or specific arterial pathologies. These findings can help clinicians in accurate diagnosis of TIA and its underlying mechanisms.