Abstracts

Rationale: Temporal lobe surgery is an effective treatment for mesial temporal lobe epilepsy, but seizure recurrence is noted in a considerable proportion of individuals. The most common reason for surgical failure may be incomplete resection of the epileptogenic zone. However, it is possible that a new epileptogenic zone may be created by surgery. We observed that some patients with mesial temporal lobe epilepsy develop a new auditory aura after epilepsy surgery. We report on the features of this de novo auditory aura in a group of patients with seizure recurrence after epilepsy surgery. Methods: Based on a search of the epilepsy surgery database, we identified 7 patients with mesial temporal lobe epilepsy and do novo postoperative auditory auras. We recorded the preoperative aura, the preoperative MRI findings, type of surgery, pathology findings, the description of the new auditory aura, and the latency from surgery to its appearance. Results: The patients were 3 women and 4 men, aged 20-42 years. Three had a right temporal lobectomy, 2 a left temporal lobectomy, and 2 a left selective amygdalohippocampectomy. The preoperative aura was consistent with a mesial temporal onset in 6 patients and one did not have an aura. All had hippocampal sclerosis, either by MRI or pathology. The de novo auditory aura was described as humming or ringing or strange noise, but one reported muffling of sounds and one reported loss of hearing. The latency from surgery to onset of aura varied from one month to 6 years. The auditory aura was either isolated or associated with other manifestations. In all patients auras occurred either in isolation or progressed to altered awareness, at times with secondary generalization. Conclusions: The de novo appearance of an auditory aura after epilepsy surgery for mesial temporal lobe epilepsy suggests a new lateral temporal epileptogenic zone, possibly secondary to surgical injury.