A communication disorder, acquired as consequence of damage to the left frontal lobe, left temporal lobe, or both, that affects comprehension, reading and writing, and speech. There are three major forms. In Broca’s aphasia, sometimes referred to as ataxic, expressive or non-fluent aphasia, speech consists of short, staccato-like sentences of a few words in which conjunctions (but, on, or) or articles (a, an, the) are omitted. It is caused by damage to Brodmann’s areas 44, 45 and 47 on the lateral surface of the left frontal lobe. With Wernicke’s aphasia, sometimes called auditory, fluent, receptive or sensory aphasia, the affected person can speak, most commonly in long, uninterrupted sentences, but the words have no meaning (often being unnecessary or even made-up). This type of aphasia is due to damage to area 22 on the lateral surface of the left temporal lobe. As for global aphasia, it consists of a combination of Broca’s and Wernicke’s aphasia, and thus an inability to communicate by means of speech or to understand the spoken word. A severe stroke may present with global aphasia and then slowly resolve into one of the other two aphasias. Other forms of aphasia are anomic (or nominal) aphasia, conduction aphasia, and transcortical aphasia.
See Cerebral cortex (or pallium), Cerebral cortex (disorders), Cortical lobes, Echolalia