Etiology of stroke in Broca's aphasia.

We reviewed clinical and diagnostic data from 36 patients with Broca's aphasia due to stroke who were evaluated at the University of Iowa Hospitals and Clinics between 1982 and 1989. The group consisted of 20 women and 16 men, aged 28-80 (median, 63.5; mean, 57.5). The presumptive cause of cerebral infarction was embolism in 15 patients (42%), atherothrombosis in 9 (25%), undetermined in 9 (25%), and "other" in 3 (8%). The ratios of women to men were 8:7, 3:6, 7:2, and 2:1, respectively. A majority of emboli were of presumed cardiac origin: atrial fibrillation, 7; prosthetic cardiac valve, 3; and recent myocardial infarction, 2. Eight of nine patients with atherothrombotic infarction had complete occlusion of the left internal carotid artery by duplex scan and/or angiography. Our data demonstrate (a) Broca's aphasia is frequently caused by cerebral embolism, (b) carotid occlusion can result in selective infarction of anterior language areas; and (c) women outnumbered men in our Broca's aphasia group. The latter finding is in contrast to a similar study of 38 patients with Wernicke's aphasia due to cerebral infarction studied at our institution, in which men outnumbered women 25 to 13, with most of the difference in the embolic and undetermined groups. Gender differences in types of aphasia might be due to a predilection for middle cerebral artery emboli to result in infarction of anterior language areas in women and posterior language areas in men.