title: Reflex myoclonus in olivopontocerebellar atrophy.
abstract: The presence of reflex myoclonus in response to touching and pin-pricking the wrist or stretching the fingers and to photic stimulation was assessed in 24 patients with a presumed diagnosis of olivopontocerebellar atrophy (OPCA) and in 30 age matched control subjects. Reflex myoclonus to soma-esthetic stimulation was found in 23 patients and in none of the controls. Photic myoclonus was present in 12 patients and in none of the controls. Electrophysiological study of the reflex myoclonus showed enhanced (> 10 microV) somatosensory evoked potentials and an associated reflex electromyographic discharge (C-wave) in 15 patients. These findings indicate that reflex myoclonus is common in OPCA and probably of cortical origin.
authors.affiliation: Clinica Universitaria, University of Navarra, Pamplona, Spain.
authors.forename: M E
authors.initials: ME
authors.lastname: Rodriguez
authors.forename: J
authors.initials: J
authors.lastname: Artieda
authors.forename: J L
authors.initials: JL
authors.lastname: Zubieta
authors.forename: J A
authors.initials: JA
authors.lastname: Obeso
mesh_terms: D001284:Atrophy / Q000000981:diagnostic imaging; D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology; D004576:Electromyography; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D007699:Kinesthesis / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009207:Myoclonus / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D009849:Olivopontocerebellar Atrophies / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D010775:Photic Stimulation; D010812:Physical Stimulation; D012018:Reflex / Q000502:physiology; D012677:Sensation / Q000502:physiology; D014057:Tomography, X-Ray Computed