Electrophysiological studies are useful in differentiating CMS

Researchers from the Institute of Myology analysed electroneuromyography data from 120 patients with congenital myasthenic syndromes (CMS) and compared them with the results of genetic studies:

  • five distinct profiles could be established from the measurement of CMAPs and repetitive stimulation of three nerves (accessory nerve, radial nerve, deep fibular nerve) at a frequency of 3 Hz,
  • repetitive CMAPs have been identified in MSCs linked to a COLQ gene mutation and in slow channel syndrome,
  • another group with mutations in DOK7, MUSK, GFPT1, GMPBB or TOR1AIP showed decrement phenomena predominantly in the accessory nerve.

This original approach improves the diagnostic algorithm of this group of neuromuscular junction pathologies.


Diagnostic yield of a practical electrodiagnostic protocol discriminating between different congenital myasthenic syndromes. Stojkovic T, Masingue M, Turmel H et al. Neuromuscul Disord. 2022 Dec;32(11-12):870-878.