Effect of electromyography on CPK and aldolase levels.

Abstract

SERUM creatine phosphokinase (CPK) and aldolase activity usually is elevated in rapidly progressive myopathies, but normal to only slightly above normal in slowly progressive myopathies and neurogenic muscular atrophies. 1 However, both muscle trauma and strenuous exercise can cause transient elevations in serum CPK levels in normal individuals. 2 Engel 3 recently studied the histologic effects of multiple needle insertions on muscle. He found that apparent myopathic changes could be produced in muscle by hypodermic and electromyographic needles. His study suggested the possibility that spurious elevations of serum CPK and aldolase activity also might occur following electromyography (EMG). The purpose of this study was to determine if the minimal muscle trauma associated with EMG could cause significant elevation of serum CPK or aldolase activity. Materials and Methods Serum CPK and aldolase levels were determined in 20 consecutive inpatients before and after EMG. There were ten girls and ten