Motor innervation and fiber type pattern in amyotrophic lateral sclerosis and in Charcot-Marie-Tooth disease.
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.
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000690:Amyotrophic Lateral Sclerosis / Q000201:enzymology* / Q000473:pathology; D002452:Cell Count; D002607:Charcot-Marie-Tooth Disease / Q000201:enzymology* / Q000473:pathology; D008058:Dihydrolipoamide Dehydrogenase / Q000378:metabolism; D006651:Histocytochemistry; D006801:Humans; D009132:Muscles / Q000201:enzymology* / Q000294:innervation; D009133:Muscular Atrophy / Q000201:enzymology*
D008058:Dihydrolipoamide Dehydrogenase; D000251:Adenosine Triphosphatases