title: Correlation between distal motor latency and compound muscle action potential in amyotrophic lateral sclerosis.
abstract: OBJECTIVE
  Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder, characterized by a selective progressive degeneration of the motor system. Electromyography is essential for the diagnosis of ALS. The measurement of motor conduction of peripheral nerves is of major importance to recognize other possible causes of progressive muscle wasting. However, there are also pathologic changes in nerve conduction studies in ALS patients.
  
  
  METHODS
  In this study we analysed the values of distal motor latency (DML), compound muscle action potential (CMAP) and motor nerve conduction velocity (MNCV) in 95 patients with definite ALS.
  
  
  RESULTS
  We found slight slowing of MNCV and moderate to strong reduction of CMAP and a prolongation of DML. We found no significant correlation between MNCV and CMAP.
  
  
  CONCLUSIONS
  The main finding of the present work was the negative correlation between DML and CMAP. It is interpreted as a very distal axonal damage as the main reason for prolongation of DML in ALS patients.
authors.affiliation: Department of Neurology and Clinical Neurophysiology, Medical School of Hannover, Hannover, Germany. Mohammadi.Bahram@mh-hannover.de
authors.forename: Bahram
authors.initials: B
authors.lastname: Mohammadi
authors.forename: Klaus
authors.initials: K
authors.lastname: Krampfl
authors.forename: Katja
authors.initials: K
authors.lastname: Kollewe
authors.forename: Amir
authors.initials: A
authors.lastname: Seyfadini
authors.forename: Johannes
authors.initials: J
authors.lastname: Bufler
authors.forename: Reinhard
authors.initials: R
authors.lastname: Dengler
mesh_terms: D000200:Action Potentials / Q000502:physiology* / Q000528:radiation effects; D000690:Amyotrophic Lateral Sclerosis / Q000503:physiopathology*; D004558:Electric Stimulation / Q000379:methods; D004576:Electromyography / Q000379:methods; D006801:Humans; D018482:Muscle, Skeletal / Q000503:physiopathology* / Q000528:radiation effects; D009431:Neural Conduction / Q000502:physiology* / Q000528:radiation effects; D011446:Prospective Studies; D011930:Reaction Time / Q000502:physiology* / Q000528:radiation effects; D013127:Spinal Nerves / Q000503:physiopathology*; D013223:Statistics as Topic / Q000379:methods