Objective: The aim of this study was to evaluate the short and long-term seizure outcome and to find predictors of outcome after epilepsy surgery in lesional posterior cortical epilepsies (PCEs).
Methods: We retrospectively studied the operative outcome in 80 consecutive adult patients with lesional PCEs who underwent resective surgery for intractable partial epilepsy between 1991 and 2006.
Results: The probability of remaining in Engel Class I was 66.3% (95% CI 60-72) at 6 months, 52.5% (95% CI 47–57) at 2 years, 52.9% (CI 45–59) at 5 years, and 47.1% (CI 42–52) at 10 years. Factors predicting poor outcome were the presence of a somatosensory aura, extra-regional spikes, incomplete resection, interictal epileptiform discharge (IED) in EEG 6 months and 2 years postsurgery, history of generalized tonic-clonic seizure (GT-CS) and the presence of focal cortical dysplasia in the resected specimen. Factors predicting good outcome were childhood onset of epilepsy, short epilepsy duration, ipsilateral spikes, visual aura, presence of well-circumscribed lesion in preoperative MRI, and a pathologically defined tumour. In the multivariate analysis, predictors were different in long and short term as fellows: incomplete resection as proven by postoperative MRI (HR 2.059 (CI 1.195-3.673) predicts seizure relapse in short-term follow-up. The presence of IED in the EEG performed 6 months after surgery (HR 2.3 (CI 1.128 -4.734) predicts seizure relapse in the long-term follow-up. However, the absence of a history of GT-CS independently predicts seizure remission in short and long-term follow-up.
Conclusions: Surgery in PCEs proved to be effective in short and long-term follow-up. Lesional posterior cortical epilepsy may be a progressive process in a substantial number of cases.