Prestroke/poststroke fMRI in aphasia: Perilesional hemodynamic activation and language recovery

Abstract

fMRI points to a contribution of left-hemisphere (LH) perilesional tissue and right-hemisphere (RH) homologues of the perisylvian “language zones” to aphasia recovery.1 Since, however, “language representation” may vary across individuals, both in terms of gyral topography and lateralization,2 the interpretation of poststroke fMRI data obtained in aphasic patients may face difficulties, e.g., in terms of a differentiation between hemodynamic responses of residual eloquent cortex and perilesional reorganization of tissue adjacent to perisylvian “language areas.” We had the extraordinary opportunity to compare fMRI data obtained during the same speech task prior to and after LH ischemic infarction—providing further insights into the development of perilesional hemodynamic responses. To our knowledge, this is the first prestroke/poststroke follow-up study in aphasia. ### Methods. #### Clinical history. At 33 years of age, the patient had participated as a healthy control subject in a language fMRI study (pre).3 Six years later, he experienced sudden right-sided hemiplegia and Broca aphasia. MRI revealed a large ischemic infarction within the territory of the left middle cerebral artery (figure, A). One year after stroke, the patient was re-examined (post), using the same design and measurement protocol (fMRI, neuropsychology). At post, the patient still had right-sided hemiparesis, but speech/language functions had almost entirely …