Altered cortical inhibition in Unverricht-Lundborg type progressive myoclonus epilepsy (EPM1).

Purpose: Progressive myoclonus epilepsies (PMEs) comprise a heterogeneous group of conditions characterized by an imbalance between excitatory and inhibitory neuronal mechanisms. The aim of this study was to assess the function of the motor cortex in Unverricht-Lundborg disease (ULD), progressive myoclonus epilepsy type 1 (EPM1).

Methods: Genetically verified EPM1 patients (n=24) were studied and compared with healthy subjects (n=24).

Clinical picture of EPM1-Unverricht-Lundborg disease.

Unverricht-Lundborg disease (ULD), progressive myoclonic epilepsy type 1 (EPM1, OMIM254800), is an autosomal recessively inherited neurodegenerative disorder characterized by age of onset from 6 to 16 years, stimulus-sensitive myoclonus, and tonic-clonic epileptic seizures. Some years after the onset ataxia, incoordination, intentional tremor, and dysarthria develop. Individuals with EPM1 are mentally alert but show emotional lability, depression, and mild decline in intellectual performance over time.