Abstracts

Rationale: Mesial temporal lobe epilepsy (MTLE) has been associated with the phenomenon of accelerated long-term forgetting (ALF), in which memories are retained normally over short delays but are then lost at an accelerated rate over days or weeks. The causes of ALF, and whether it represents a consolidation deficit distinct from the one associated with forgetting over short delays, remain unclear. It could be due to prevention of consolidation process by the ongoing epileptic activity or the damage developed already in TLE. In this study we aimed to demonstrate the effect of surgery on the ALF phenomena which may provide an explanation to the cause. Methods: We have evaluated 43 patients ( 24F/19M), mean age 37.2 years ( 23-56yrs) with MTLE related to hippocampal sclerosis who had anterior temporal lobectomy (ATL) and followed for at least 5 years (mean11 years,6 -16 years). All of them were seizure free after surgery. Control group was consisted of 9 healthy controls . All were given Turkish verbal learning test (SBST) and were tested for learning, immediate recall and recognition at 30 min, 1 week and 6 week intervals. Afterwards, accelerated forgetting rate was calculated and the scores were analysed statistically. Results: The results of of SBST test after 30 minutes and difference scores estimated for delayed recall did not show statistically significant difference in neither patient nor control groups. Conclusions: Patients with favorable outcome and without consolidation deficit after ATL may provide a further evidence for the relationship between the effect of ongoing epileptic activity and accelerated long-term forgetting.