Abstracts

Rationale: The amygdala is thought to play an important role in the genesis of temporal lobe seizures. However, the epileptogenic pathology of the amygdala is only infrequently described. Methods: Clinical data and pathological diagnosis were reviewed for consecutive 65 patients who underwent temporal lobe surgery for treatment of epilepsy in our institution between 2003 and 2007. Anterior temporal lobectomy with amygdalo-hippocampectomy was employed as a standard procedure. Results: Dysplasia in the amygdala was found in 9 patients, including 5 associated with hippocampal sclerosis and 4 without hippocampal sclerosis. The amygdala abnormality was suggested as a primary epileptogenic lesion by pre-operative MRI in all of the latter 4 cases. Electroencephalographic finding and seizure semiology were similar between them. The 4 cases with amygdala dysplasia and no hippocampal sclerosis were characterized by the absence of initial precipitating factors such as febrile seizures and by relatively late onset of epilepsy. Post-operative seizure freedom was achieved in all except one patient. Conclusions: Dysplasia of the amygdala is infrequent finding in the surgical cases of temporal lobe epilepsy (13.8%). It can appear in association with hippocampal sclerosis (dual pathology) or as a primary epileptogenic pathology. The presence of amygdala dysplasia seems not related to post-operative seizure outcome as far as the current surgical strategy includes removal of amygdala. However, careful interpretation of the pre-operative imaging would be important when choosing more selective procedures for treatment of epilepsy.