Abstracts

Rationale: Surgical treatment of temporal lobe epilepsy (TLE), especially TLE associated with with hippocampal sclerosis (TLE-HS), generally has a favorable prognosis. However, about 30% of patients continue to have seizures or have recurrence after a seizure-free interval. Analysis of clinical features may be helpful in identifying patients at risk of a poor seizure outcome. Methods: We retrospectively reviewed clinical features in 30 patients with TLE-HS (15 right and 15 left) who underwent anterior temporal lobectomy (ATL). All patients had video-EEG monitoring, MRI brain with temporal lobe epilepsy protocol and interictal FDG-PET. Eight patients underwent invasive video-EEG monitoring with subdural electrodes, four patients had ictal and interictal SPECT, and four had MR spectroscopy. Surgical outcome was determined by Engel's classification, with class 1 regarded as good outcome. Statistical analysis was carried out by using Fisher's exact test and Spearman's rank correlation coefficient (rho) Results: There were 16 females and 14 males. Age at seizure onset was 2-40 years (mean 8 years). Duration of preoperative seizures was 9-40 years (mean 23). Age at surgery was 18-50 years (mean 27 years). Mean duration of follow-up was 3.5 years. Overall, twenty-one patients became seizure-free (70%) and 9 continued to have seizures. Three out of 15 patients who underwent left ATL, and 6 out of 15 patients with right ATL had poor outcome (p = 0.0247). Fifteen patients had auras. Atypical auras, such as a funny feeling, were associated with a poor outcome as compared to typical auras, such as abdominal, gustatory and psychic, (0 out of 4 class 1 versus 10 out of 11, p = 0.004, rho 0.853). Automatisms were present in 20 patients. Patients with violent automatisms (stomping feet, wandering, prominent vocalization) had poor outcome as compared to those with subtle oral-facial and hand automatisms (1 out of 10 class 1 versus 10 out of 10, p<0.01, rho 0.926). Eight of 16 patients with secondarily generalized seizures had poor outcome whereas only 1 out of 14 patients without secondarily generalized seizures had poor outcome (p=0.009, rho 0.467). Conclusions: Among clinical variables, atypical auras, violent automatisms and the presence of secondarily generalized seizures predict a poor seizure outcome after ATL in patients with TLE-HS. Side of resection does not appear to influence outcome.