title: Electrophysiological study of myoclonic seizures in children.
abstract: To investigate the neurophysiological mechanisms underlying myoclonic seizures in childhood, we measured the latency between the onset of electromyogram (EMG) potentials and that of corresponding spikes obtained by the back-averaging method. The subjects were nine patients, with various epileptic syndromes, ranging in age from 2 months to 15 years, 11 months. The numbers of seizure events obtained by averaging ranged from five to 51 with a mean of 25. The latencies between averaged spike-and-wave complexes and deltoid EMG potentials ranged from 21 to 80, with a mean of 38 ms. Comparing these results with reported age-matched physiological conduction times, these latencies appeared to be slightly prolonged in all of our patients. Our results support the hypothesis that myoclonic seizures are produced through either a cortical or a subcortical generator, via a polysynaptic mechanism acting on muscles, rather than a monosynaptic corticospinal pathway.
authors.affiliation: Department of Pediatrics, Tokyo Women's Medical College, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Oguni
authors.forename: K
authors.initials: K
authors.lastname: Mukahira
authors.forename: T
authors.initials: T
authors.lastname: Uehara
authors.forename: M
authors.initials: M
authors.lastname: Matsuzaki
authors.forename: M
authors.initials: M
authors.lastname: Osawa
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D004576:Electromyography; D004594:Electrophysiology; D004831:Epilepsies, Myoclonic / Q000175:diagnosis* / Q000503:physiopathology*; D006801:Humans; D007223:Infant