Broca's aphasia

Meaning: Aphasia is an acquired loss of language ability caused by brain damage. Broca's area, in the left inferior frontal gyrus of the frontal lobe in most people, supports speech production and grammar. Damage gives nonfluent, effortful, halting speech made mostly of content words, called telegraphic speech (for example, "walk dog park"). Comprehension is relatively preserved, so patients often know what they want to say and become frustrated. Repetition is also impaired.

On the MCAT: A passage describes a patient who follows spoken commands but speaks in short, labored phrases. The question asks for the lesion site (Broca's area, frontal lobe) or for the contrast with other aphasias. Wernicke's aphasia, from damage to Wernicke's area in the left temporal lobe, gives fluent, grammatical-sounding speech that lacks meaning, with poor comprehension. Conduction aphasia, from damage to the arcuate fasciculus linking the two areas, leaves comprehension and fluency fairly intact but repetition poor.

Common confusion: Students swap the two names. Broca's problem is production (B for broken, effortful speech), and Wernicke's problem is comprehension. Broca's aphasia is not weakness of the mouth muscles and not a loss of general intelligence. The deficit is in language itself, so writing is usually affected too.