ETIOPATHOGENESIS OF TRANSIENT ISCHEMIC ATTACKS AND MINOR ISCHEMIC STROKES - A COMMUNITY-BASED STUDY IN SEGOVIA, SPAIN

Background and Purpose-We sought to analyze the etiology and underlyin g vascular risk factors of transient ischemic attacks (TIAs) and minor ischemic strokes (MISs). Methods-We prospectively studied the vascula r risk factors and etiologic categories in 235 patients with TIAs and MISs from a community-based register in a rural area of Spain. Five et iologic categories were considered: (1) cardioembolism, (2) large-arte ry atherosclerosis, (3) small-artery disease, (4) other etiologies, an d (5) undetermined etiology. Systematic investigations included neuroi maging (CT/MRI) and vascular studies (duplex scan/MR angiography and a ngiography in selected cases). Results-The two most frequent etiologic categories were small-artery disease (31%) and cardioembolism (26%). Large-artery atherosclerosis was detected in 11% of the patients, Sign ificant carotid stenosis (greater than or equal to 50%) was present in 13% of patients with carotid territory events. No cause could be foun d or it was uncertain in almost one third of the patients. The distrib ution of etiologic categories was similar in TIAs and MISs. The most p revalent vascular risk factors were as follows: arterial hypertension (50%), smoking (26%), atrial fibrillation (20%), hypercholesterolemia (17%), diabetes (15%), ischemic heart disease (12%), and peripheral va scular disease (3%). Carotid bruits were detected in 3% of the patient s. Conclusions-An etiologic classification of TIAs and MISs is feasibl e. The two most frequent: pathogenetic mechanisms in our study were sm all-artery disease and cardioembolism. The prevalence of large-artery atherosclerosis was low.