Brainstem Myoclonus

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


Two types of brainstem myoclonus are recognized: (1) exaggerated startle myoclonus and (2) reticular reflex myoclonus. Brainstem myoclonus is generated mainly in the reticular formation which lies close to the accessory nerve nuclei. Clinically, the muscle jerks of reticular reflex myoclonus are usually generalized with proximal more than distal and flexor more than extensor predominance. Voluntary action and sensory stimulation may increase the muscle jerks. Neurophysiologically, the first recruited muscle which jerks is the sternocleidomastoid or trapezius muscle. The myoclonic discharge then travels down the spinal cord and up the brainstem.

Supplementary material

The patient exhibits myoclonic jerks involving her shoulders and proximal portions of her upper extremities bilaterally. The jerks occur spontaneously but are more frequent after pressure over the sternum.

Brainstem myoclonus.mp4 (MP4 13,107KB)


  1. 1.
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    Hanakawa T, Hashimoto S, Iga K, et al. Carotid brainstem reflex myoclonus after hypoxic brain damage. J Neurol Neurosurg Psychiatry. 2000;69:672–4.PubMedCentralPubMedCrossRefGoogle 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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