Abstracts

Cognitive side effects (CSEs) occur in many patients taking antepileptic drugs (AEDs). The predictors of these side effects, however, are unknown. As part of the Columbia AED database, we reviewed patient background, medical history, medication, efficacy, and side effects for 1286 patients with epilepsy. We reviewed the incidence of cognitive side effects in the 1222 patients on 8630 AED regimens for which we have detailed information since January 1, 2000. CSEs included were aphasia, poor concentration, poor memory, psychomotor slowing, cognitive slowing, confusion/disorientation, or word finding difficulty. Using univariate chi-square tests, we analyzed the association of 91 variables in predicting the incidence of CSEs and the occurrence of CSEs that led to a medication or dosage change. Significance was set at p[lt]0.01. Of 1222 patients, 285 (23.3%) experienced CSEs and 144 (11.8%) experienced CSEs that led to a dosage or medication change. The two most significant risk factors for cognitive side effects were use of topiramate (p[lt]0.001) and a history of CNS infection (p[lt]0.01). Less significant risk factors included simple partial seizures and use of oxcarbazepine, phenytoin or zonisamide. The factors that were most associated with a decreased risk of CSEs were juvenile myoclonic epilepsy (p[lt]0.01) and use of lamotrigine (p[lt]0.01); static encephalopathy was also associated with a decreased risk of CSEs. Patients with epilepsy are most likely to experience cognitive side effects if they have a history of CNS infection or if they are receiving topiramate. Patients are least likely to experience CSEs if they have juvenile myoclonic epilepsy or if they are receiving lamotrigine. (Supported by The Columbia AED Database is supported by Elan, GlaxoSmithKline, Ortho McNeill, Pfizer, and UCB Pharma.)