Cognitive dysfunction after generalized tonic-clonic status epilepticus in adults.

Abstract

Generalized tonic-clonic status epilepticus (GTC-SE) is considered a risk for cognitive impairment. Research with standardized tools is scarce and non-conclusive. We systematically assessed short-term and long-term cognitive function after GTC-SE. Thirty-three patients were tested after the clinical post-ictal phase of GTC-SE (timepoint 1) and again after 1year (timepoint 2). Twenty controls were examined with the same tests. Tests from Cambridge Neuropsychological Test Automated Battery were used. Motor screening test (MOT) assessed motor speed, delayed matching to sample (DMS) and paired associates learning (PAL) assessed memory, and Stockings of Cambridge (SOC) assessed executive function. Estimated premorbid IQ and radiologically visible brain lesions were controlled for in adjusted results. Outcome measures were z-scores, the number of standard deviations a score deviates from the mean of a norm population. At timepoint 1, unadjusted patient results were significantly below both norm and control group performances on all subtests. Patient mean was 1.9 z-scores below controls (P<.001) on PAL total errors. Results remained significant for PAL and DMS after adjustments. Patient results improved at timepoint 2, but memory tests remained lower than norms and for controls. An executive dysfunction emerged on the most complex SOC stage (z-score difference -0.83; P=.008, adjusted difference -0.94; P=.02). Memory and learning impairment in the early phase after SE and late developing executive dysfunction remained significant after adjusting for estimated premorbid IQ and pre-SE brain lesions. Results suggest that GTC-SE poses a risk for cognitive impairment.