Clinical, Laboratory, and Imaging Characteristics of Transient Ischemic Attack Caused by Large Artery Lesions: A Comparison between Carotid and Intracranial Arteries

BACKGROUND/AIMS: The aims of this study were to determine the differences in clinical characteristics and the risk of ischemic stroke between patients with transient ischemic attack (TIA) attributable to extracranial carotid and intracranial artery occlusive lesions. METHODS: Among 445 patients admitted to our stroke care unit within 48 h of TIA onset between April 2008 and December 2013, 85 patients (63 men, mean age 69.4 years) with large artery occlusive lesions relevant to symptoms were included in this study. The primary endpoints were ischemic stroke at 2 and 90 days after TIA onset. RESULTS: Twenty-eight patients had carotid artery occlusive lesions (extracranial group), and 57 patients had intracranial artery occlusive lesions (intracranial group). Patients in the intracranial group were significantly younger, had lower levels of fibrinogen, and were less likely to have occlusion when compared with those in the extracranial group. Eleven patients in the extracranial group and none in the intracranial group underwent revascularization procedures within 90 days of TIA onset. The 2-day risk (14.2 vs. 0%, p = 0.044) and the 90-day risk (17.1 vs. 0%, p = 0.020) of ischemic stroke after TIA onset were significantly higher in the intracranial group than in the extracranial group. CONCLUSIONS: Among our patients with TIA caused by large artery disease, patients with intracranial artery occlusive lesions were more frequent and were at higher risk of early ischemic stroke than those with extracranial carotid artery occlusive lesions. These data highlight the importance of prompt assessment of intracranial artery lesions in patients with TIA.