Factors associated with subjective cognitive function in epilepsy and psychogenic non-epileptic seizures

To identify factors associated with subjective cognitive complaints in people with presumed seizure disorders referred for video electroencephalogram monitoring (VEM).

Adult patients admitted for inpatient VEM were recruited. Objective cognitive function was measured with the Neuropsychiatry Unit Cognitive Screening Tool, subjective cognitive function with the Quality of Life in Epilepsy Inventory-89 subscales, and anxiety and depressive symptoms with the Hospital Anxiety and Depression Scale. Multivariate Bayesian general linear models were used to identify predictors of subjective cognitive function.

331 patients met inclusion criteria. Mean age was 39.3 years and 61.9 % patients were female. Diagnoses included epilepsy, psychogenic non-epileptic seizures (PNES) or both conditions. Depression, anxiety and objective cognitive function were predictors of subjective cognitive function across all domains. Depression was the strongest predictor of subjective memory and attention, whilst objective cognition was the strongest predictor of subjective language function. Mood also mediated the relationship between objective function and subjective function across all domains to varying extents; depression exerted the strongest effect of 22 % for the memory domain; conversely, language domain was least influenced by mood, with depression mediating 11 % and anxiety mediating only 9% of the subjective-objective relationship.

Mood and objective cognitive function are both important contributors to subjective cognitive function for patients undergoing VEM. Clinicians should consider referring patients with cognitive complaints for both neurocognitive workup and neuropsychiatric evaluation. Future work may examine the effects of treating concomitant mood disorders on subjective cognitive function.