The role of speech manifestations in the lateralization of temporal lobe seizures was reviewed at the Section of Epilepsy and Clinical Neurophysiology, Department of Neurology, Cleveland Clinic Foundation, Cleveland, OH by the review of videotapes of 100 complex seizures in 35 patients who underwent temporal lobectomy for intractable epilepsy. All patients had prolonged EEG video monitoring with scalp and subdural electrodes and their speech dominance was determined with an intracarotid amobarbital test. Speech manifestations were classified as vocalization, normal speech, or abnormal speech. Vocalizations of sound without speech quality occurred during the seizure in 48.5% of patients. Normal speech occurred ictally in 34% of patients. Abnormal speech (speech arrest, dysphasia, and dysarthria) occurred in 51% of patients either during the seizure or postictally. Only postictal dysphasia and ictal identifiable speech had significant lateralizing value: 92% of patients with postictal dysphasia had their seizures originating from the dominant temporal lobe, and 83% of those with ictal identifiable speech had seizures localized to the nondominant side. [1]
COMMENT. This study shows that speech manifestations are common in complex partial seizures of temporal lobe origin and can help to lateralize the origin of the seizure. John Hughlings Jackson noted that seizures in the dominant hemisphere could result in speech abnormalities and Penfield found that electrical stimulation of the speech areas in the dominant hemisphere produced dysphasia whereas stimulation of the motor speech area of either hemisphere produced vocalization.