title: Post-exercise exhaustion in Lambert-Eaton myasthenic syndrome.
abstract: OBJECTIVE
  To study post-exercise exhaustion by decrement (PEE-D) systematically in 24 repetitive nerve stimulation (RNS) tests in 14 patients with Lambert-Eaton myasthenic syndrome (LEMS).
  
  
  METHODS
  In the abductor digiti quinti muscle, the compound muscle action potential (CMAP) amplitude and 3Hz responses for 2s were obtained with the supramaximal stimulation at rest, immediately after (PE0), 30s after (PE30s), and at 1, 2, 3, and 4m after 10-s exercise.
  
  
  RESULTS
  There was a 377% increment in the CMAP amplitude at PE0 and a mild increment (+26%) at PE30s. A transient but significant improvement (-22%) in the decremental response was observed at PE0, and a gradual worsening of decrement in subsequent tests, with the worst decrement noted (-50%) at PE2m.
  
  
  CONCLUSIONS
  PEE-D was found 2m after exercise in LEMS.
  
  
  CONCLUSIONS
  PEE-D may be physiologically closest to the reversible myasthenic fatigue after exercise observed in LEMS patients.
authors.affiliation: Department of Neurology, The University of Alabama at Birmingham, Birmingham, AL, USA. Electronic address: shinjoh@uab.edu.
authors.forename: Shin J
authors.initials: SJ
authors.lastname: Oh
authors.affiliation: Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Hatanaka
authors.affiliation: Neurological Institute, Tokyo Women's Medical University School of Medicine, Tokyo, Japan.
authors.forename: Eiichi
authors.initials: E
authors.lastname: Ito
authors.affiliation: Kawasaki Medical School, Okayama, Japan.
authors.forename: Taiichi
authors.initials: T
authors.lastname: Nagai
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000328:Adult; D000368:Aged; D004558:Electric Stimulation; D015444:Exercise / Q000502:physiology*; D005221:Fatigue / Q000503:physiopathology*; D005260:Female; D006801:Humans; D015624:Lambert-Eaton Myasthenic Syndrome / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*
keywords: LEMS; Lambert-Eaton myasthenic syndrome; Post-exercise exhaustion; RNS test