RT Journal Article
SR Electronic
T1 Measurement of rise time of averaged muscle action potential in normal subjects and patients with myopathy.
JF Journal of Neurology, Neurosurgery & Psychiatry
JO J Neurol Neurosurg Psychiatry
FD BMJ Publishing Group Ltd
SP 56
OP 62
DO 10.1136/jnnp.43.1.56
VO 43
IS 1
A1 A J Simons
YR 1980
UL http://jnnp.bmj.com/content/43/1/56.abstract
AB 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.