Repeating through the insula: evidence from two consecutive strokes.

Mixed transcortical aphasia is a very rare syndrome characterized by intact repetition, despite severe impairment in all other language modalities. In some cases, however, preservation of repetition is accompanied by intact reading. We report the case of a left-handed man who, after a subcortical stroke in the left hemisphere, showed the typical features of mixed transcortical aphasia with spared repetition and reading. After 10 days, a second stroke, involving the anterior insula and adjacent white matter bundles, markedly deteriorated repetition while his reading abilities recovered. By comparing features of repetition and reading before and after the second stroke, we provide evidence for the existence of a modular organization of language abilities, pointing to the primary role of the insula and surrounding white matter in phonological processing.