Article Text

Download PDFPDF

Myokymia and impaired muscular relaxation with continuous motor unit activity.
  1. F D Lublin,
  2. P Tsairis,
  3. L J Streletz,
  4. R A Chambers,
  5. W F Riker,
  6. A Van Poznak,
  7. S W Duckett


    We have studied two cases of the syndrome of myokymia and impaired muscular relaxation with continuous motor unit activity. Both patients complained of muscle twitching, weakness, stiffness, and hyperhydrosis during their illness. Myokymia was present over the entire body in both. On repetitive testing of muscle strength each patient showed initial fatigue followed by increasing strength as he continued his efforts. Both patinets improved on phenytoin therapy at high blood levels. Nerve conduction velocities were decreased. Electromyograms showed continuous electrical activity at rest which persisted during sleep and spinal anaesthesia but was diminished by curare. Intravital staining with methylene blue in one case demonstrated sprouting and beading of motor nerve terminals with multiple innervation of muscle fibres. The neurophysiological and pathological findings in these two cases indicate an abnormality of peripheral nerve in this disorder.

    Statistics from

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.