Teaching Video NeuroImages: Bereitschaftspotential: A Neurophysiologic Test for Functional or Voluntary Jerks
A 47-year-old man presented with a 2-year history of recurrent, short-lasting, and sudden jerky movements, which resembled myoclonus (video 1). Examination was normal. Brain and spine MRI were normal. Surface EMG and EEG revealed cortical activation preceding the abnormal movements (figure), consistent with Bereitschaftspotential and the diagnosis of functional jerks.