Measurement of rise time of averaged muscle action potential in normal subjects and patients with myopathy.

AUTOR(ES)

Simons, A J

RESUMO

As a result of diminution of the number of muscle fibers in patients with myopathy, the rise time of the fast negative phase of the spike potentials in the EMG becomes shorter. By using a small special purpose computer (averager) a mean action potential is obtained from which the rise time of the "spike" is determined. In normal muscles the mean value is 509 microseconds (SD 118). Myopathic muscles show a mean value of 225 microseconds (SD 76). There is a slight overlap and uncertainty between 280 and 370 microseconds. Because of the short time needed to examine the muscle for this parameter many muscles may be examined during one routine EMG.

Documentos Relacionados

• Severe insulin-resistant diabetes mellitus in patients with congenital muscle fiber type disproportion myopathy.
• Muscle fibre type changes in hypothyroid myopathy.
• Respiratory chain enzyme defects in patients with idiopathic inflammatory myopathy.
• Resting transmembrane potential difference of skeletal muscle in normal subjects and severely ill patients
• Corticosteroid myopathy.