Essential Myoclonus

  • Roongroj Bhidayasiri
  • Daniel Tarsy
Part of the Current Clinical Neurology book series (CCNEU)


Myoclonus is either the only or the most prominent finding in essential myoclonus. Myoclonus is therefore a nearly isolated phenomenon from which the patient usually experiences relatively mild disability. Essential myoclonus may be sporadic or genetically determined and either does not progress or progresses very slowly over many years. Hereditary essential myoclonus is characterized by onset before age 20, dominant inheritance with variable severity, a benign clinical course compatible with an active life and normal longevity, and the absence of other neurological signs. The myoclonus typically is generalized, is exacerbated by muscle activation, and is substantially decreased by alcohol ingestion. The term “myoclonus-dystonia” syndrome has been introduced because of the common occurrence of dystonia in these cases.


Public Health Internal Medicine Partial Response Daily Activity Muscle Activation 
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Supplementary material

The patient exhibits generalized myoclonus at rest involving the trunk and lower more than upper extremities.

Essential myoclonus.mp4 (MP4 3,792KB)


  1. 1.
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    Caviness JN, Brown P. Myoclonus: current concepts and recent advances. Lancet Neurol. 2004;3:598–607.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2012

Authors and Affiliations

  • Roongroj Bhidayasiri
    • 1
    • 2
  • Daniel Tarsy
    • 3
  1. 1.Chulalongkorn Center of Excellence on Parkinson’s Disease and Related DisordersChulalongkorn University HospitalBangkokThailand
  2. 2.Department of NeurologyDavid Geffen School of Medicine at UCLALos AngelesUSA
  3. 3.Department of NeurologyHarvard Medical School Beth Israel Deaconess Medical CenterBostonUSA

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