Cortical stimulation mapping in a patient with foreign accent syndrome: case report.

Foreign accent syndrome is a rare language output disorder characterized by changes in various speech features leading to a perceived foreign accent. There are few cases reported in the literature. Due to the rarity of this condition, information regarding the functional neuroanatomy of FAS is lacking. We present the case of a 60-year-old woman with a left anterior parietal lobe breast carcinoma metastasis who developed foreign accent syndrome (FAS). This patient presented to the emergency room with right upper extremity weakness, facial weakness, and altered speech. Neurological examination revealed the patient's speech to be dysarthric and accented, but otherwise appropriate. Brain magnetic resonance (MR) imaging demonstrated a 3cm x 3cm x 3cm lesion in the left anterior parietal lobe. The patient underwent craniotomy for resection of the mass. Intra-operative cortical stimulation mapping demonstrated the lesion to be confined to somatosensory cortex and gross total resection was performed. There were no new neurological deficits post-operatively. To our knowledge, this is a unique case of FAS due to breast carcinoma metastasis. Additionally, this is the first documented case of electrocortical function stimulation mapping of language and Rolandic cortex in a patient with FAS.