The critical role Wernicke's area in sentence repetition

The anatomical correlates of persistent deficits in sentence repetition were studied in a group of 32 right-handed patients with fluent aphasia caused by left hemisphere ischemic stroke. Patients whose ability to repeat remained impaired by 6 months after onset almost without exception had damage to Wernicke's area. Furthermore, all patients with damage to Wernicke's area had impaired repetition 6 months after onset. The most consistent lesion correlating with chronic impairment of repetition, therefore, was one destroying parts or all of Wernicke's area. Lesions outside of this area typically resulted in milder impairment of repetition that resolved within a few months. Only 5 patients had no repetition impairment when tested early (1 month after onset). These patients all had lesions anterior to the rolandic fissure, some including Broca's area.