title: Late-onset myoclonic epilepsy in Down's syndrome (LOMEDS).
abstract: The aim of this paper is to report a patient with late-onset myoclonic epilepsy in Down's syndrome (LOMEDS) as a differential diagnosis of adult-onset progressive myoclonic epilepsies. A 55-year-old male with Down's syndrome (DS) is described who developed progressively frequent myoclonus and generalized myoclonic-tonic seizures (GMTSs) at the age of 52. EEG recordings demonstrated background slowing and generalized polyspike-wave discharges occasionally associated with myoclonic jerks, leading to the classification of primary generalized epileptic myoclonus. Descriptions of late-onset epilepsy in DS patients are rare. However, a review of the pertinent literature revealed at least two other cases of elderly DS patients developing progressive myoclonic epilepsy after the onset of dementia. We suggest that late-onset myoclonic epilepsy in Down's syndrome as characterized here should be considered in the differential diagnosis of adult-onset myoclonic epilepsies. LOMEDS apparently shares features with myoclonic epilepsy in Alzheimer's disease (AD) and Unverricht-Lundborg disease (ULD) caused by a mutation on chromosome 21. Since life expectation of DS patients has markedly increased, LOMEDS may be more frequent than currently acknowledged.
authors.affiliation: Klinik für Neurologie, Philipps-University Marburg, Germany.
authors.forename: J C
authors.initials: JC
authors.lastname: Möller
authors.forename: H M
authors.initials: HM
authors.lastname: Hamer
authors.forename: W H
authors.initials: WH
authors.lastname: Oertel
authors.forename: F
authors.initials: F
authors.lastname: Rosenow
mesh_terms: D000367:Age Factors; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics; D003704:Dementia / Q000150:complications; D003937:Diagnosis, Differential; D004314:Down Syndrome / Q000150:complications* / Q000235:genetics; D004569:Electroencephalography; D004831:Epilepsies, Myoclonic / Q000150:complications* / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged