Neuropsychological performance and seizure control after subsequent anteromesial temporal lobe resection following selective amygdalohippocampectomy.

Objective: Selective amygdalohippocampectomy (sAHE) is a well-established treatment for temporal lobe epilepsy, commonly with favorable neuropsychological outcome. Yet, it is still unknown if subsequent resection of the anteromesial temporal lobe (AMTLR), when necessary, deteriorates neuropsychological performance in this selected group of patients. Thus, we evaluated the clinical and neuropsychological data of patients who, due to insufficient seizure control after sAHE, received a subsequent ipsilateral AMTLR and compared these findings with patients who did not receive a second resection (control group).

Methods: Patients' characteristics and neuropsychological data were assessed and analyzed in the reoperated as well as in the control group at each step of treatment. Experienced neuropsychologists conducted the standardized examination focusing on verbal, figural and working memory, speech fluency and attention. Preoperative diagnostics included further continuous video-electroencephalography monitoring, high-resolution magnetic resonance imaging and functional transcranial Doppler sonography.

Results: Eighty patients having received sAHE in our center from 11/2007 to 02/2013 were included in this study. Seventeen of these patients underwent subsequent AMTLR. Thirteen of these were available for follow-up after the second surgery and twelve had a comprehensive neuropsychological testing at all three steps. Analyzing the neuropsychological data revealed no significant differences compared with controls. On the individual level, the data demonstrated that improvement in a subdomain was more frequent than decline, if the performance had already deteriorated after the first procedure. Seizure control improved significantly (p < 0.001) in all patients after subsequent AMTLR resulting in seven patients being seizure-free at follow-up.

Significance: Subsequent AMTLR following sAHE can be a safe procedure to improve seizure outcome in selected patients. In our series the risk for further neuropsychological deterioration after the second procedure was low. The neuropsychological performance after the sAHE can be a valuable criterion to advise patients who are eligible for a second surgery on their risk of further cognitive decline.