Abstract
Various factors are suspected to be responsible for the changes of skeletal muscle of the aged, and among the changes of muscle, there are many similar findings to those of the neuromuscular diseases. A comparative study was performed with the biopsied muscles from the 80 aged-persons by pathological methods, including the enzyme histochemistry and electron microscopy. Muscles biopsied from 150 cases of the neuromuscular diseases were referred.
Results were as follows:
1) Muscle changes of the aged were variegated, but the neurogenic changes of various grades were most frequently observed.
2) Histochemically type II fiber atrophy was prominent in the aged.
3) Various myopathic changes were also observed in many muscles of the aged. Among them, “red-ragged fiber”, nemaline rods, lipid storage including lipopigment and curvilinear body, tubular aggregates and proliferation of t-system (honeycomb like structure) were frequent findings.
4) Various nuclear changes.
5) Thickening of intramuscular capillary basement me mbrane was observed moderately.
6) Deformity and reduction of the subsynaptic folds of the motor endplates.
It is suspected that various factors, accompanying with the ageing process, may act on the motor neuron (anterior horn cell, peripheral nerve, motor endplate and muscle) and are responsible for the neuropathic and myopathic changes of muscles of the aged.
