Abstracts

Neuropsychological evaluation as a part of the presurgical evaluation of patients with intractable epilepsy can help elucidate seizure focus and provide predictive data concerning the possibility of memory decline following resection of the temporal lobe. However, a patient[apos]s performance on neuropsychological tests can be affected by factors not directly related to the question at hand, including the effects of antiepileptic drugs (AEDs). Older AEDs have been documented to have effects on cognitive functioning, specifically aspects of memory, attention, and processing speed. There is less data concerning newer AEDs developed within the past decade, though at least one newer AED, topiramate, has been demonstrated to have significant cognitive effects. Understanding the influence of AEDs on test performance is vital for interpretation of performance on cognitive testing. The purpose of the current study is to determine if levetiracetam, a relatively recently introduced AED, has any significant cognitive side effects at the dosages typically prescribed for patients with intractable epilepsy., Forty-seven patients were administered a battery of neuropsychological tests as a part of a comprehensive work-up prior to epilepsy surgery. Twenty of these patients were taking levetiracetam as a part of their medication regimen (Focus: 8 left temporal, 7 right temporal, 1 bitemporal, 4 non-temporal). The neuropsychological evaluation included assessment of the standard domains including intellectual functioning, academic functioning, attention, language, visuospatial ability, memory, motor performance, executive functioning, and emotional status., Performance on neuropsychological tests did not differ significantly between the levetiracetam and non-levetiracetam groups; however, a subgroup of eight patients in the levetiracetam group performed well below expectation on the WAIS-III Working Memory Index (WMI), as compared to only 3 in the patient group that was not taking levetiracetam ([chi]²[1] = 4.4, [italic]p[/italic] [lt] .05). In most cases, WMI was significantly lower than higher-order verbal intellectual abilities as measured by the WAIS-III Verbal Comprehension Index (average discrepancy = 20.8 points, [italic]p [/italic][lt] .01 based on normative data). Demographic (e.g., level of education) and seizure-related (e.g., years since seizure onset) variables did not explain the differences between individuals in this cluster and the other patients. The majority of these patients reported significant occupational impairment, and several displayed rather dramatic declines in functioning since adding levitiracetam to their medication regimen., These findings suggest that levetiracetam may produce adverse cognitive side effects, at least in working memory, in a cluster of patients taking the medication for seizure control. These deficits, when present, can be disruptive to occupational or academic functioning.,