ApoE-ε4 is associated with reduced memory in long-standing intractable temporal lobe epilepsy

Objective: To investigate the relationship between the apolipoprotein (ApoE) epsilon 4 allele and memory performance ( verbal and nonverbal) in patients with medically intractable temporal lobe epilepsy (TLE) who underwent temporal lobectomy. Methods: Presurgical and postsurgical memory performance was examined in 87 adult patients with TLE (epsilon 4 = 22; non-epsilon 4 = 65) to determine whether the expression of ApoE-epsilon 4 may be associated with memory performance in this population and to examine how this relationship may be affected by duration of epilepsy. Results: There was a significant interaction between ApoE-epsilon 4 status and duration of epilepsy such that epsilon 4 carriers with a long duration of epilepsy demonstrated the poorest memory performance on both verbal and nonverbal measures. This relationship was observed both before and after temporal lobectomy, with little change in test performance over time. Conclusions: The ApoE-epsilon 4 allele interacts with longstanding seizures to affect memory performance, both verbal and nonverbal, in patients with medically intractable temporal lobe epilepsy.