Utility of automated memory measures in identifying cognitive impairment in adults with epilepsy

Cognitive impairment is prevalent in epilepsy and often presents at the time of initial diagnosis. This study sought to validate brief, self-administered, iPad-based recognition memory tasks in a sample of patients with epilepsy and to examine their screening utility in identifying patients with cognitive impairment.

The Words and Faces tests were administered to 145 adult patients with epilepsy along with a neuropsychological battery. Correlation analyses examined the convergent and divergent validity of the Words and Faces tests, and a series of logistic regression analyses examined discriminative ability in identifying patients with and without cognitive impairments on neuropsychological measures. Patient performance was compared to that of a healthy control group (n = 223), and the relationship between the Words and Faces test performance and disease-related variables (i.e., antiepileptic medication burden, seizure lateralization/localization) was examined.

The Words and Faces tests were positively correlated with traditional paper-and-pencil neuropsychological measures of episodic memory, with generally moderate to large effect sizes (r > .40), while correlations between the Words and Faces tests and non-memory measures were generally small in magnitude (r < .30). Patients with epilepsy had significantly lower scores on Words and Faces tests compared to healthy controls, and performance was associated with antiepileptic medication burden and seizure localization. The Words and Faces tests demonstrated good predictive accuracy in identifying any cognitive impairment (concordance (c) statistic = .77) and excellent predictive accuracy (c = .85) in identifying patients with impairments on traditional memory measures. The Words and Faces tests also demonstrated reasonable discrimination for impairments in non-memory domains including executive function, language, attention, processing speed, and visuospatial ability (c = .62 -.70). Importantly, the Words and Faces Immediate Index performed just as well as the Total Score (which included delayed memory performance), suggesting a short version of this measure is sufficient for identifying patients with cognitive impairment.

The Words and Faces tests are valid, computerized tools that can be used to screen for memory and other cognitive impairment in adults with epilepsy.