title: Cortical mechanisms mediating asterixis.
abstract: We describe a patient with chronic renal failure who suffered multifocal action-induced jerks. Electromyography (EMG) recorded the typical silence of asterixis. Back-averaging the EEG activity preceding the EMG silent periods in the forearm showed a biphasic wave antedating the asterixis by 23 ms. Somatosensory evoked potentials (SEPs) after median nerve stimulation were pathologically enlarged on both hemispheres. Brain-mapping of the biphasic wave preceding asterixis and the giant SEPs indicated a common origin in the sensorimotor cortex. This observation provides further documentation of a cortical origin for some types of asterixis in humans.
authors.affiliation: Department of Neurology, Clinica Universitaria, University of Navarra, Pamplona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Artieda
authors.forename: J
authors.initials: J
authors.lastname: Muruzabal
authors.forename: R
authors.initials: R
authors.lastname: Larumbe
authors.forename: C
authors.initials: C
authors.lastname: García de Casasola
authors.forename: J A
authors.initials: JA
authors.lastname: Obeso
mesh_terms: D001931:Brain Mapping / Q000295:instrumentation; D002540:Cerebral Cortex / Q000503:physiopathology*; D004569:Electroencephalography / Q000295:instrumentation*; D004576:Electromyography / Q000295:instrumentation*; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000503:physiopathology*; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology; D009207:Myoclonus / Q000503:physiopathology; D009468:Neuromuscular Diseases / Q000503:physiopathology*; D011187:Posture / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013003:Somatosensory Cortex / Q000503:physiopathology