Presence of Bereitschaftspotential preceding psychogenic myoclonus: clinical application of jerk-locked back averaging. Issue 6 (June 1995)

• Record Type: Journal Article
• Authors: Terada, K; Ikeda, A; Van Ness, P C; Nagamine, T; Kaji, R; Kimura, J; Shibasaki, H
• Is Part Of: Journal of neurology, neurosurgery and psychiatry. Volume 58:Issue 6(1995)
• Page Start: 745
• Page End: 747
• Publication Date: 1995-06
• Subjects: Neurology -- Periodicals; Nervous system -- Surgery -- Periodicals; Psychiatry -- Periodicals; 616.8
• DOI: 10.1136/jnnp.58.6.745
• Languages: English
• ISSNs: 0022-3050

Abstract

Abstract : The method of jerk-locked back averaging was applied to six patients with clinically diagnosed psychogenic myoclonus. Five patients had a slow negative EEG shift corresponding to Bereitschaftspotential at the central region starting 0.7 to 2.1 seconds before the onset of the myoclonic jerk. One patient had no potential preceding the myoclonic jerk, whereas a small negative potential preceded the voluntary movement mimicking the jerk. The demonstration of Bereitschaftspotential before an apparently involuntary myoclonic jerk helps the clinical diagnosis of psychogenic myoclonus, although the absence of Bereitschaftspotential does not necessarily indicate that the movement is involuntary. Jerk-locked back averaging is clinically useful as a specific laboratory examination in this condition.