Preoperative clinical evaluation, outline of surgical technique and outcome in temporal lobe epilepsy

Temporal lobe epilepsy (TLE) is the most common type of refractory epilepsy. The mechanisms of epileptogenesis and seizure semiology of the mesial and neocortical temporal lobe epilepsy are discussed. The evaluation and selection of patients for TLE surgery requires team work: the different clinical aspects of neuropsychological evaluation, magnetic resonance and functional imaging (positron emission tomography, single photon emission computed tomography and magnetoenephalography) are reviewed. In our programme of epilepsy surgery at Kuopio University Hospital, Finland, we have performed 230 temporal resections from 1988 until 2002. Preoperative diagnostic EEG-videotelemetry often required intracranial monitoring and it has proved to be safe and efficient. The indications and technique for tailored temporal lobe resection with amygdalohippocampectomy used in our institution, as well as the complications, are described. Our analysis of outcome after temporal lobe surgery included 140 consecutive adult patients between 1988 and 1999; one year after the operation in unilateral TLE the Engel I-II outcome was observed in 68% of the patients. Outcome of surgery improved significantly after introduction of the standardised MR imaging protocol from 1993; 74% of patients with unilateral TLE achieved Engel I-II outcome.