title: Value of short exercise and short exercise with cooling tests in the diagnosis of myotonic dystrophies (DM1 and DM2).
abstract: BACKGROUND
  Standard electromyography (EMG) is useful in the diagnosis of myotonic dystrophy type 1 (DM1) and type 2 (DM2), but it does not differentiate between them. The aim of this study was to estimate the utility of the short exercise test (SET) and short exercise test with cooling (SETC) in differentiating between DM1 and DM2.
  
  
  METHODS
  SET and SETC were performed in 32 patients with DM1 (mean age 35.8 ± 12.7 years) and 28 patients with DM2 (mean age 44.5 ± 12.5 years).
  
  
  RESULTS
  We observed a significant decline in compound motor action potential (CMAP) amplitude in DM1 with both SET and SETC immediately after effort. In DM2, there was no marked change in CMAP amplitude with either SET or SETC.
  
  
  CONCLUSIONS
  SET and SETC may serve as useful tools for clinical differentiation between DM1 and DM2, and they may be used as a guide for molecular testing.
authors.affiliation: Department of Neurology, Medical University of Warsaw, Banacha 1A, Warsaw, 02-097, Poland.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Gawel
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Szmidt-Salkowska
authors.forename: Anna
authors.initials: A
authors.lastname: Lusakowska
authors.forename: Monika
authors.initials: M
authors.lastname: Nojszewska
authors.forename: Anna
authors.initials: A
authors.lastname: Sulek
authors.forename: Wioletta
authors.initials: W
authors.lastname: Krysa
authors.forename: Marta
authors.initials: M
authors.lastname: Rajkiewicz
authors.forename: Andrzej
authors.initials: A
authors.lastname: Seroka
authors.forename: Anna M
authors.initials: AM
authors.lastname: Kaminska
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000328:Adult; D003937:Diagnosis, Differential; D003955:Diagnostic Tests, Routine / Q000379:methods*; D055724:Electrophysiological Phenomena; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology; D020967:Myotonic Disorders / Q000175:diagnosis* / Q000503:physiopathology; D009223:Myotonic Dystrophy / Q000175:diagnosis* / Q000503:physiopathology
keywords: channelopathy; cooling; electromyography; exercise test; myotonic dystrophy