Abstracts

Rationale: Older adult patients account for a very small percentage of patients who have received surgical treatment for epilepsy. Previous reports of seizure outcome in elderly included heterogeneous pathologies. There have been few studies reported outcome of surgery for hippocampal sclerosis (HS) in older patients. Methods: We retrospectively reviewed patients who underwent surgical treatment for medially refractory temporal lobe epilepsy at King Chulalongkorn Memorial Hospital between January 2004 and March 2009. Study inclusion criteria consisted of patients who were 16 years or older, had unilateral HS and no other lesions on magnetic resonance imaging (MRI) and pathologically proven hippocampal sclerosis. All patients had a minimum of 1-year follow-up. All patients underwent a complete neurologic history and physical examination, MRI and 24-hour scalp video electroencephalography (EEG) monitoring. Wada test, single photon emission tomography (SPECT) and positron emission tomography (PET) were performed in selected patients. The procedures performed were anterior temporal lobectomy (ATL). Invasive monitoring with implanted subdural electrodes was performed whenever noninvasive recordings were nonconcordant. All surgeries were performed by a single neurosurgeon and surgical pathology was obtained in all patients.Seizure outcome was classified according to Engel s classification based on their last postoperative seizure status. Patients were divided into 2 groups: seizure-free (Engel 1) and not seizure-free (Engel 2-4). Results: A total of 200 patients fulfilled the inclusion criteria. Sixteen patients were older than 50 years (mean age, 55.5 years) and 184 patients were younger than 50 years (mean age 32.9 years). There was no significant difference between the two groups in gender, side of surgery, length of follow-up and history of febrile seizures. The mean onset of seizure was 13.1 years in younger than 50 age group and 24.7 years in the older group (p=0.019). The mean duration of epilepsy prior to surgery was 20.0 years in the younger than 50 age group and 30.8 years in the older age group (p=0.010). There were no predictors associated with outcome but duration of epilepsy had a trend to be statistically significant (p=0.061). Nine of the 16 older patients (56.3%) had seizure free outcome compare with 79.4% of the younger patients (p=0.041)(Table 1). Surgical complications in the older age group were significantly higher than young age group (p<0.001).All complications were transient and there was no mortality. Conclusions: Surgical treatment of TLE-HS in elderly patients offers a chance of seizure-free but lesser than younger patients. Surgical treatment of TLE-HS should be considered as early as possible to maximize the outcome.