Clinical features and carotid duplex sonography in patients with carotid transient ischemic attacks.

Background: Transient ischemic attack (TIA) is recognized as a precursor of cerebral infarction. It is prompted by an embolism from extracranial carotid artery disease. However, extracranial carotid disease is less prevalent in Chinese patients. Non-invasive duplex sonography has been used for initial screening for extracranial carotid artery disease.
Methods: One hundred and twenty-seven consecutive patients with carotid TIA were divided into two groups according to sonographic results, Group I: < or = 50%, and Group II: > 50% stenosis of the carotid artery. The two groups were compared for the clinical manifestations, risk factors, brain computed tomography (CT) findings and subsequent stroke. An age and sex-matched group of patients with lacunar stroke was also collected from the same neurosonological data bank for further comparative analysis.
Results: The mean age at onset was 59 +/- 12 (mean SD) years. Hypertension was the most common risk factor. The most common symptom was transient focal motor deficit (73%) with or without other complaints. Eighty-two percent of the TIA episodes were less than one hour in duration. In Group I, there were 114 patients (90%) with stenosis < or = 50% ipsilateral to the symptomatic side. Group II included only 13 patients (10%) with the ipsilateral carotid artery stenosis > 50%. Mean age was older and cigarette smoking was more common in Group II (p < 0.05). Otherwise, no significant difference was noted between the two groups in initial characteristics of TIAs, risk factors, brain CT findings or subsequent stroke. Further, there was no statistical significant difference between the TIA and lacunar stroke groups in the degree of carotid stenosis.
Conclusions: Hypertension was the most common risk factor for carotid TIAs. The prevalence of extracranial carotid artery disease was low in Chinese patients with carotid TIAs. The severity of the carotid artery was not predictive of recurrence of TIA or of subsequent stroke. There was no significant difference between patients with TIA and with lacunar stroke in sonographic findings of extracranial carotid arteries.