Motor Unit Activity Extracted from the Electromyographic Full Interference Pattern of Extraocular Muscles

Abstract

A new technique is presented for the extraction of single action potentials from the electromyographic interference pattern obtained from extraocular muscles. 28 patients suffering from a variety of disorders of eyeball motility have been investigated. Frequency was preselected and the duration of action potential (AP) was measured. The statistical analysis included minimal, maximal and span durations, average, measure of dispersion, standard deviation, symmetry of distribution, skewness, degree of flatness of curve and excess. Sharp differences were found between the groups of normal, myopathic, infranuclear and nuclear recordings. The technique is simple, exact, reliable, completely automatic and very fast; its major drawback is that it requires the use of a computer. The technique and the statistical analysis that is possible, seem to have value both as research and clinical tools of investigation.