The National Institute of Neurological and Communicative Disorders and Stroke initiated the Stroke Data Bank, which is a multicenter project to prospectively collect data on the clinical course and sequelae of stroke. Additional objectives were to provide information that would enable a standard diagnostic clinical evaluation, to identify prognostic factors, and to provide planning data for future studies. A brief description of the structure and methods precede the baseline characterization of 1,805 patients enrolled in the Stroke Data Bank between July 1983 and June 1986. Two thirds of these patients were admitted within 24 hours after stroke onset. Medical history, neurologic history, and hospitalization summaries are presented separately for the following stroke subtypes: infarction, unknown cause; embolism from cardiac source; infarction due to atherosclerosis; lacune; parenchymatous or intracerebral hemorrhage; subarachnoid hemorrhage; and other. The utility and limitations of these data are discussed.

The time of onset of ischemic stroke was determined for 1,167 of 1,273 patients during the collection of data by four academic hospital centers between June 30, 1983, and June 30, 1986. More strokes occurred in awake patients from 10:00 AM to noon than during any other 2-hour interval. The incidence of stroke onset declined steadily during the remainder of the day and early evening. The onset of stroke is least likely to occur in the late evening, before midnight.

• Eighteen patients had caudate nucleus infarcts (10 left-sided; 8 right-sided). Infarcts extended into the anterior limb of the internal capsule in 9 patients, and also the anterior putamen in 5 patients. Thirteen patients had motor signs, most often a slight transient hemiparesis. Dysarthria was common (11 patients). Cognitive and behavioral abnormalities were frequent, and included abulia (10 patients), agitation and hyperactivity (7 patients), contralateral neglect (3 patients, all right caudate), and language abnormalities (2 patients, both left caudate). The majority of patients had risk factors for penetrating artery disease. Branch occlusion of Heubner's artery, or perforators from the proximal anterior or middle cerebral arteries were the posited mechanism of infarction.

Several lines of previous evidence have suggested that androgens affect cognitive abilities. In an effort to characterize this defect, we compared 19 men with idiopathic hypogonadotropic hypogonadism with 19 control men and with five men with acquired hypergonadotropic hypogonadism that had developed after puberberty. The 19 patients with idiopathic hypogonadism had markedly impaired spatial ability in comparison to either controls or subjects with acquired hypogonadism (P<0.05). Moreover, the spatial ability of the patients correlated positively with their testicular volume (P<0.05). Androgen-replacement therapy in six of the patients did not improve their spatial ability.