SPEECH AND THE DOMINANT SUPERIOR FRONTAL GYRUS - CORRELATION OF ICTALSYMPTOMS, EEG, AND RESULTS OF SURGICAL RESECTION

Two patients with seizures characterized by speech arrest had astrocyt oma in the superior frontal gyrus (SFG) of the left hemisphere. Preope rative video EEG monitoring of seizures using subdural electrode array s showed that comprehension, crude vocalization, and limb and tongue m ovements were preserved during speech arrest. One patient had difficul ty writing during seizures. Ictal EEG onset was localized to the SFG w ithout involvement of Broca's area. Electrical stimulation of SFG elec trodes reproduced the speech arrest and writing difficulty. Resection of this region reduced seizures but did not result in lasting speech d eficit. Cessation of speech with electrical stimulation of the superio r frontal gyrus occurs by interrupting control of muscles required for speaking, which occurs independently of simple 'negative' motor effec ts. We postulate that functional redundancy is the basis for resection of this region without producing significant speech deficits.