title: Chloride channel dysfunction study in myotonic dystrophy type 1 using repeated short exercise tests.
abstract: This exploratory study aimed to evaluate the electrophysiological profiles of patients with myotonic dystrophy type 1 (DM1) and to assess their correlations with genotype and phenotype.
  
  
  
  Twenty-two patients with genetically confirmed DM1 were included. Global motor testing score, severity of myotonia, occurrence of cardiac disturbances, and CTG repeat number were recorded. All patients underwent repeated short exercise tests after 7 min of cooling.
  
  
  
  Two trajectories could be distinguished following 3 periods of exercise, although most clearly following the third exercise period. Cardiac disturbances were more common among patients who had a B-type trajectory (larger decrement in compound muscle potential amplitude and slower recovery) following the third exercise period.
  
  
  
  While the electrophysiological pattern in each profile appeared to confirm chloride muscle channel impairment, the B-type trajectory may suggest dysfunction of other muscle channels in DM1 and their link with cardiac disturbances. Muscle Nerve 54: 104-109, 2016.
authors.affiliation: Service de Neurologie, Centre Hospitalier Universitaire de Toulouse, Hôpital Purpan, 1 Place Baylac, 31059, Toulouse, France.
authors.forename: Blandine
authors.initials: B
authors.lastname: Acket
authors.affiliation: Clinical Epidemiology Unit, Centre Hospitalier Universitaire de Toulouse, Faculté de Médecine de Purpan, Toulouse, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Lepage
authors.affiliation: Federation of Cardiology, Centre Hospitalier Universitaire de Toulouse, Hôpital Rangueil, Toulouse, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Maury
authors.affiliation: Service de Neurologie, Centre Hospitalier Universitaire de Toulouse, Hôpital Purpan, 1 Place Baylac, 31059, Toulouse, France.
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Arne-Bes
authors.affiliation: Service de Neurologie, Centre Hospitalier Universitaire de Toulouse, Hôpital Purpan, 1 Place Baylac, 31059, Toulouse, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Cintas
mesh_terms: D000328:Adult; D018118:Chloride Channels / Q000502:physiology*; D004569:Electroencephalography; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006331:Heart Diseases / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009223:Myotonic Dystrophy / Q000235:genetics* / Q000503:physiopathology*; D065636:Myotonin-Protein Kinase / Q000235:genetics; D012720:Severity of Illness Index; D018911:Trinucleotide Repeats / Q000235:genetics; D055815:Young Adult
chemical_list: D018118:Chloride Channels; C585517:DMPK protein, human; D065636:Myotonin-Protein Kinase
keywords: electromyography; muscle channelopathies; myotonia; myotonic dystrophy; repeated exercise tests