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Electromyographic and morphological functional compensation in late poliomyelitis
Author(s) -
Einarsson Gisli,
Grimby Gunnar,
Stålberg Erik
Publication year - 1990
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.880130214
Subject(s) - reinnervation , motor unit , medicine , electromyography , electrophysiology , motor neuron , anatomy , physical medicine and rehabilitation , motor unit recruitment , disease
Patients with prior poliomyelitis may experience muscle function deterioration decades after onset of disease. The present study is aimed at describing electromyographic and morphometric evidence of muscular compensation and of on‐going muscular instability. Ten subjects 42–62 years of age with onset of polio 25–52 years earlier were studied with macro EMG, single‐fiber EMG (SFEMG), muscle strength measurement, and morphometrical analysis of muscle biopsies from the vastus lateralis muscle. SFEMG revealed increased fiber density (FD) and large macro‐MUP potentials indicating pronounced reinnervation as compensation to loss of motor neurons. From electrophysiological data of motor unit size, morphometric measures of fiber size, and muscle strength data, the minimal degree of motor neuron loss was estimated to be greater than 70%.