Utility and validity of a brief cognitive assessment tool in patients with epileptic and nonepileptic seizures

Cognitive impairment is not uncommon in patients with epilepsy, and may relate to the underlying pathophysiology of epilepsy, the effects of seizures, or epilepsy treatment. Formal neuropsychological testing is not available in many centers, and few cognitive screening tools have been validated in an epilepsy population. We aimed to ascertain the reliability and validity of a multidimensional cognitive screening instrument, the Neuropsychiatry Unit Cognitive Assessment Tool (NUCOG), in a mixed epilepsy population.

One hundred sixty-one of 177 consecutive patients admitted to a video telemetry unit were assessed with the NUCOG and classified with respect to seizure semiology, and a subset (n=33) were formally neuropsychologically assessed.

Scores did not differ between patients with epileptiform, those with nonepileptiform, and those with mixed EEGs on the NUCOG, nor between patients with focal and those with generalized epilepsies. Patients with a temporal lobe focus performed more poorly in general, and in memory specifically, than patients with an extratemporal focus. Scores on the NUCOG subscales Memory, Attention, and Executive Functioning correlated significantly with neuropsychological testing of these same domains, although patients were not impaired on measures of language or spatial function.

The NUCOG appears to correlate strongly with neuropsychological functioning in a number of key cognitive areas affected in patients with epilepsy, and appears to robustly detect memory impairment in patients with temporal lobe epilepsy.