Article Text

Download PDFPDF
Facial myokymia in inherited peripheral nerve hyperexcitability syndrome


Peripheral nerve hyperexcitability syndrome comprises a heterogeneous group of diseases, clinically characterised by myokymia, fasciculation, muscle cramps and stiffness. The causes are either immune mediated or non-immune mediated. Non-immune-mediated forms are mostly genetic, relating to two main genes: KCNQ2 and KCNA1. Patients with KCNQ2 gene mutations typically present with epileptic encephalopathy, benign familial neonatal seizures and myokymia, though occasionally with purely peripheral nerve hyperexcitability. We report a woman with marked facial myokymia and distal upper limb contractures whose mother also had subtle facial myokymia; both had the c.G620A (p.R207Q) variant in the KCNQ2 gene. Patients with familial myokymia and peripheral nerve hyperexcitability syndrome should be investigated for KCNQ2 variants. This autosomal dominant condition may respond to antiepileptic medications acting at potassium channels.

  • myokymia
  • peripheral nerve hyperexcitability syndrome
  • KCNQ2 gene mutations
View Full Text

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.