Abstracts

Rationale: Memory complaints are very common in the epilepsy clinic and have a negative impact on quality of life. Although memory research in epilepsy has focused on short term memory, long-term memory has received less attention. The goal of the current study is to analyze long-term memory retrieval in an older cohort of epilepsy patients and to determine whether the presence of epileptiform abnormalities during sleep are correlated with performance. Methods: We prospectively recruited patients with epilepsy older than 50 undergoing ambulatory EEG from the Brigham and Women’s epilepsy clinic. Patients were asked to perform a declarative memory task consisting of learning the location of at least 5 of 15 pairs of colored pictures on a 5 x 6 grid prior to their EEG study. They were also asked to rate their subjective sleepiness using the Stanford sleepiness Scale and to report their level of memory concern (1-a great deal; 2-somewhat; 3-only a little; 4-not at all). Their recall of the picture pairs was re-assessed upon their return 24 hours later, and their EEG was analyzed for the presence of epileptiform abnormalities during sleep. Results: A total of 22 subjects were prospectively recruited, including 9 controls. Mean age of the 13 epilepsy patients was 62.3 years (range: 50-72,65% female) and 59.1 years (range: 51-70, 44% female) for 9 controls. The epilepsy localization was 62% temporal (5/10 left lateralized).  Epilepsy patients endorsed higher levels of fatigue (scale = 1-7; median: 3 vs.1, p=0.005) and were more concerned about their memory (median: 2 vs.4, p=0.003). The 24-hour retention rate for the epilepsy patients was 65% compared to 63% for controls with no statistically significant difference. When only patients with epileptiform activity during the intervening night were analyzed, there was a trend for them to perform worse than epilepsy patients with no such activity that night (47% vs. 81%, p=0.09). Conclusions: Patients with epilepsy had higher rates of fatigue and were more concerned about their memory as compared to a control population. Long-term memory retrieval was similar between groups. But there was a trend for patients with epileptiform abnormalities during post-learning sleep to perform worse the next day than those without, suggesting that epileptiform abnormalities may disrupt sleep-dependent memory consolidation. Funding: AJ Trustey Epilepsy Research-Endowed Fund