Negative myoclonus

Q: What is negative Myoclonus? 

Answer: Negative mуοϲlоnսs is a sudden, involuntary, shock-like movement caused by the sudden interruption of muscle contraction.

The conventional understanding of myoclonus only considers a sudden, involuntary, shock-like movement caused by sudden muscular contraction, which is positive mуοϲloոսѕ. It can also occur by inhibition of muscle contraction, which is called negative mуοϲlοnսs.

Myoclonus has also been classified on the anatomical basis:

• Corticalmуοϲlоnսs 
• Cortical-subcortical mуοϲlоոuѕ
• Subcortical-nonsegmental mуοϲloոսs
• Segmental mуοϲlοnսs
• Peripheral mуοϲlоnuѕ 

Another way is to describe it based on causes:

• Physiologic myoclonus
• Essential myoclonus
• Epileptic myoclonus
• Primary myoclonus

#neurology

References:

1. Pollini L, van der Veen S, Elting JWJ, Tijssen MAJ. Negative Myoclonus: Neurophysiological Study and Clinical Impact in Progressive Myoclonus Ataxia. Mov Disord. 2024 Apr;39(4):674-683. doi: 10.1002/mds.29741. Epub 2024 Feb 22. PMID: 38385661.

2. Rubboli G, Tassinari CA. Negative myoclonus. An overview of its clinical features, pathophysiological mechanisms, and management. Neurophysiol Clin. 2006 Sep-Dec;36(5-6):337-43. doi: 10.1016/j.neucli.2006.12.001. Epub 2007 Jan 23. PMID: 17336779.