Gabapentin as add-on therapy in focal epilepsy: a computerized EEG study

Objectives: Gabapentin (GBP) possesses a well documented clinical efficacy in those types of focal epilepsy otherwise resistant to conventional antiep ileptic drugs (AEDs); on the basis of this, it appears important to investi gate the drug effects on the EEG epileptiform and background activity. Methods: Twenty-five patients with cryptogenic or symptomatic partial epile psy resistant to conventional AED treatment were included in the study. All patients underwent long-term video-EEG recordings before and after GBP add ition (900-1200 mg/day). Results: Quantitative analysis of the interictal EEC paroxysms revealed tha t GBP had no effect on the rate of occurrence of interictal and ictal EEG a bnormalities. GBP was active in delimiting the spatial extent of the interi ctal spiking activity in those patients who displayed a significant reducti on (greater than or equal to 50%) in seizure occurrence (32% of the patient s). EEG background activity recorded under rest condition from 18 out of 25 epileptic patients, before GBP therapy, was characterised by a higher cont ent of the slow spectral components (delta and theta) with respect to contr ol subjects. After GBP addition, the increase of theta relative power was a lso evident during task performance. Conclusions: These findings suggest that GBP does not interfere with the ge neration of interictal EEG spiking while it appears to reduce the susceptib ility to seizures concomitantly with a limiting effect on the spiking activ ity spatial extent. The utilization of GBP in controlling focal seizures is reinforced by the absence of negative influence on cognitive functioning. (C) 2000 Elsevier Science ireland Ltd. All rights reserved.