Praxis induction and its relationship with cognition in genetic generalized epilepsy

Praxis induction (PI) is a reflex trait defined as the precipitation of epileptic discharges (ED) or seizures by cognition-guided tasks that often involve visuomotor coordination and decision-making. This is a characteristic of genetic generalized epilepsy (GGE), and especially of juvenile myoclonic epilepsy (JME). Additionally, several studies have described dysexecutive traits in these patients. Our objective was to analyze PI in the different syndromes of GGE and explore the relationship between PI and cognitive performance.

Sixty-one adult patients with GGE underwent video-electroencephalograph (EEG) during which a neuropsychological activation protocol (NPAP) was performed: reading, writing, calculations, crosswords, and tangram. Praxis induction was defined by the presence of ED during the NPAP with a persistence of at least twice seen on the basal EEG. All patients also underwent a comprehensive cognitive evaluation.

We observed PI in 22 out of 61 patients (36%). Grouped by syndrome, PI was more frequent in adult patients with persistent childhood or juvenile absence epilepsy (JAE, 60%), followed by JME (42.1%) and in a lesser grade in patients with only tonic-clonic generalized seizures (9%). Patients classified as having PI did not obtain worse results in the cognitive evaluation. The presence of ED during the performance of a test was associated with a trend to lower results in that specific test.

Our study showed a relevant presence of PI in patients whose absence epilepsy persists into adulthood, and not only in JME, the syndrome classically associated with PI. According to our results, PI as a reflex trait does not imply necessarily a poorer cognitive phenotype, but the induction of frequent ED during the tasks could be associated with transient cognitive impairment.