Motor innervation and fiber type pattern in amyotrophic lateral sclerosis and in Charcot-Marie-Tooth disease

Muscle Nerve. Mar-Apr 1978;1(2):133-9. doi: 10.1002/mus.880010205.


A quantitive study of the terminal innervation ratio (TIR) was conducted using 18 amyotrophic lateral sclerosis (ALS) and 12 Charcot-Marie-Tooth disease (CMT) muscle biopsies. Morphometric and histochemical analyses of muscle fibers were performed in 9 ALS and 6 CMT biopsies. The results revealed that TIR and type grouping were significantly greater in CMT than in ALS. The proportion of type 3 fibers was higher in ALS, though the proportion of intermediate and type 0 fibers was significantly higher in CMT. The atrophy factor was significantly greater in type 3 than in types 1 and 2 fibers, but it was not significantly different in type 0 and intermediate fibers as compared to types 1 and 2, It appears, therefore, that CMT has a better capacity for collateral reinnervation than ALS. Type 0 and intermediate fibers may represent altered endproducts of successful collateral reinnervation.

MeSH terms

  • Adenosine Triphosphatases / metabolism
  • Amyotrophic Lateral Sclerosis / enzymology*
  • Amyotrophic Lateral Sclerosis / pathology
  • Cell Count
  • Charcot-Marie-Tooth Disease / enzymology*
  • Charcot-Marie-Tooth Disease / pathology
  • Dihydrolipoamide Dehydrogenase / metabolism
  • Histocytochemistry
  • Humans
  • Muscles / enzymology*
  • Muscles / innervation
  • Muscular Atrophy / enzymology*


  • Dihydrolipoamide Dehydrogenase
  • Adenosine Triphosphatases