Geen nadelige effecten op de intelligentie 6 jaar na chirurgische behandeling wegens epilepsie

OBJECTIVE: To evaluate the long-term effects of epilepsy surgery on intelligence. DESIGN: Prospective descriptive. METHOD: The group included 20 patients of the Instituut voor Epilepsiebestrijding, Heemstede, and the Epilepsiecentrum Kempenhaeghe, Heeze, the Netherlands, who suffered from medication-resistant epilepsy originating from the temporal lobe, in 9 patients from the left lobe (mean age: 33.1 years), in 11 from the right one (34.6 years). The epilepsy focus was removed surgically (Academic Hospital, Utrecht). The scores on the 'Wechsler adult intelligence scale' (WAIS) were determined before the operation and 6 months, 2 years and 6 years after operation. RESULTS: The mean WAIS IQs before operation were: verbal IQ (VIQ): 111.8 and performance IQ (PIQ): 117.7 in the group treated on the left and VIQ: 113.5 and PIQ: 112.4 in the group treated on the right. The mean gains 6 years after operation were 0.8 and 2.6 VIQ-points and 8.7 and 8.5 PIQ-points respectively. In the patients operated on the left the difference between VIQ and PIQ was significant 2 and 6 years after operation. The increase in IQs remained within what could be expected in retests. Only for the VIQ of patients treated on the left was a smaller retest effect found. CONCLUSION: These figures show that in the long term epilepsy surgery does not have an adverse outcome on the intelligence.