Myasthenia gravis with presynaptic neurophysiological signs: Two case reports and literature review

Neuromuscul Disord. 2015 Aug;25(8):646-50. doi: 10.1016/j.nmd.2015.04.012. Epub 2015 May 5.

Abstract

The distinction between myasthenia gravis and Lambert-Eaton myasthenic syndrome is based on clinical, neurophysiological and immunological features. We hereby report two cases with a clinical diagnosis of myasthenia gravis and neurophysiological features consistent with a pre-synaptic neuromuscular transmission defect. Both patients had increased anti-acetylcholine receptor antibody titres and showed a good response to cholinesterase inhibitors, along with a >100% facilitation of the compound muscle action potential on electrophysiological studies. We provide a review of English literature studies on co-existing features of myasthenia gravis and Lambert-Eaton myasthenic syndrome, and discuss diagnostic controversies.

Keywords: 3,4-Diaminopyridine; Cholinesterase inhibitors; Lambert–Eaton myasthenic syndrome; Myasthenia gravis; Presynaptic neurophysiological pattern.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antibodies
  • Female
  • Humans
  • Lambert-Eaton Myasthenic Syndrome / diagnosis*
  • Male
  • Middle Aged
  • Muscle Weakness
  • Myasthenia Gravis / diagnosis*
  • Myasthenia Gravis / physiopathology
  • Neural Conduction
  • Neuromuscular Junction
  • Peroneal Nerve / physiopathology
  • Presynaptic Terminals / physiology
  • Receptors, Cholinergic / immunology
  • Synaptic Transmission
  • Young Adult

Substances

  • Antibodies
  • Receptors, Cholinergic