Age-related electrical status epilepticus during sleep and epileptic negative myoclonus in DRPLA

Hereditary dentatorubral-pallidoluysian atrophy (DRPLA) (MIM 125370)1 is a rare autosomal dominant neurodegenerative disorder found mostly in Japanese people and caused by an expansion of the CAG repeat in the DRPLA gene on chromosome 12p.2 Childhood-onset patients generally have a phenotype of progressive myoclonus epilepsy (PME) with a large expansion of the CAG repeat.2 In the present study, we report a patient with DRPLA who showed epilepsy with electrical status epilepticus during slow sleep (ESES) or the extraordinary EEG abnormality of continuous spike-waves during slow wave sleep (CSWS) and epileptic negative myoclonus in childhood. Epilepsy with CSWS generally occurs in cryptogenic patients or symptomatic ones with nonprogressive brain pathology and is an age-related and self-limited disorder.3 Remarkably, his CSWS on EEG remitted spontaneously with age, as it does in other patients without progressive disorder, although the underlying degeneration of the brain continued relentlessly. This patient, who was born after an uneventful pregnancy, had a father with ataxia and dementia and a diagnosis of DRPLA in later life. The patient's early …