Cortical mechanisms mediating asterixis
Artieda J., Muruzábal J., Larumbe R., García de Casasola C., Obeso J.A.
Department of Neurology, Clínica Universitaria, University of Navarra, Pamplona, Spain
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.
CITATION Mov Disord. 1992;7(3):209-16