title: Electrically evoked multiplet discharges are associated with more marked clinical deterioration in motor neuron disease.
abstract: BACKGROUND
  The aim of this study was to determine whether electrically evoked multiplet discharges (MDs) are related to severity of clinical deterioration in motor neuron disease (MND).
  
  
  METHODS
  Stimulated high-density surface electromyographic (HDsEMG) recordings were performed in thenar muscles. Data were collected from 31 MND patients. MDs from the HDsEMG recordings were determined at baseline. ALSFRS-R scores were obtained at baseline and at a maximum of 16 weeks follow-up.
  
  
  RESULTS
  The presence of MDs was associated with progressive deterioration of ALSFRS-R score (P = 0.02) and fine motor function (FMF) (P < 0.001). Patients who had a higher number of motor units that generated MDs (r = 0.61, P < 0.001) and patients who had a higher number of MDs (as percentage of applied stimuli) (r = 0.59, P = 0.001) had a more severe decline in FMF.
  
  
  CONCLUSIONS
  Electrically evoked MDs are associated with more marked clinical deterioration in patients with MND.
authors.affiliation: Department of Clinical Neurophysiology, University Medical Centre Rotterdam, P.O. Box 2040, 3000, CA Rotterdam, The Netherlands.
authors.forename: Boudewijn T H M
authors.initials: BT
authors.lastname: Sleutjes
authors.affiliation: Department of Clinical Neurophysiology, University Medical Centre Rotterdam, P.O. Box 2040, 3000, CA Rotterdam, The Netherlands.
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Maathuis
authors.affiliation: Department of Neurology, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands.
authors.forename: Pieter A
authors.initials: PA
authors.lastname: van Doorn
authors.affiliation: Department of Clinical Neurophysiology, University Medical Centre Rotterdam, P.O. Box 2040, 3000, CA Rotterdam, The Netherlands.|Department of Clinical Physics, Máxima Medical Centre Veldhoven, Veldhoven, The Netherlands.
authors.forename: Joleen H
authors.initials: JH
authors.lastname: Blok
authors.affiliation: Department of Clinical Neurophysiology, University Medical Centre Rotterdam, P.O. Box 2040, 3000, CA Rotterdam, The Netherlands.|Department of Clinical Neurophysiology, SEIN Heemstede, Heemstede, The Netherlands.
authors.forename: Gerhard H
authors.initials: GH
authors.lastname: Visser
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000328:Adult; D000368:Aged; D004576:Electromyography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D016472:Motor Neuron Disease / Q000503:physiopathology*; D018482:Muscle, Skeletal / Q000503:physiopathology; D012720:Severity of Illness Index
keywords: EMG; MND; disease progression; ectopic motor unit activity; multiplet discharges