Mixed transcortical aphasia
Mixed transcortical aphasia is the least common of the three transcortical aphasias (behind transcortical motor aphasia and transcortical sensory aphasia, respectively). Mixed transcortical aphasia is characterized by severe speaking and comprehension impairment, but with preserved repetition. People who suffer mixed transcortical aphasia struggle greatly to produce propositional language or to understand what is being said to them, yet they can repeat long, complex utterances or finish a song once they hear the first part.
In this rare type of aphasia, Broca's area, Wernicke's area, and the arcuate fasciculus are intact but the watershed region around them is damaged. This damage isolates these areas from the rest of the brain. The most frequent etiology of mixed transcortical aphasia is stenosis (narrowing) of the internal carotid artery.