title: Cortical myoclonus in levodopa-responsive parkinsonism.
abstract: We observed myoclonic movements of the fingers and wrists in two patients with a levodopa-responsive parkinsonian syndrome most consistent with Parkinson's disease. These patients were studied with electrophysiological techniques. Brief (<50 ms) myoclonic electromyographic discharges showed a time-locked relationship to a focal premovement electroencephalographic potential. Somatosensory-evoked potentials were not enlarged and long-latency reflexes were not grossly exaggerated. This pattern of electrophysiological findings can be distinguished from those previously found in other parkinsonian syndromes. These results provide evidence for a cortical origin of the myoclonus seen in these patients.
authors.affiliation: Department of Neurology, Mayo Clinic Scottsdale, Arizona 85259, USA.
authors.forename: J N
authors.initials: JN
authors.lastname: Caviness
authors.forename: C H
authors.initials: CH
authors.lastname: Adler
authors.forename: S
authors.initials: S
authors.lastname: Newman
authors.forename: R J
authors.initials: RJ
authors.lastname: Caselli
authors.forename: M D
authors.initials: MD
authors.lastname: Muenter
mesh_terms: D000368:Aged; D000978:Antiparkinson Agents / Q000008:administration & dosage*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000187:drug effects / Q000503:physiopathology*; D004569:Electroencephalography / Q000187:drug effects; D004576:Electromyography / Q000187:drug effects; D005500:Follow-Up Studies; D006801:Humans; D007980:Levodopa / Q000008:administration & dosage*; D008297:Male; D009207:Myoclonus / Q000188:drug therapy / Q000503:physiopathology*; D010300:Parkinson Disease / Q000188:drug therapy / Q000503:physiopathology*
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa