How to evaluate persistent but incidental elevation of serum CK
What is the approach to evaluating a persistent but incidental elevation of serum CK?
Perform an EMG if symptoms of weakness, myalgia, cramps, or tenderness are present. If the EMG findings are suggestive of a myopathy, a muscle biopsy may be considered.
If the examination is normal, have the patient rest for 3 to 4 days and recheck serum CK early in the morning.
If levels are still greater than 1.5 times the upper limit of normal for ethnicity and gender, an EMG and a muscle biopsy might be beneficial. If serum CK is within normal limits, then follow the patient clinically.
A muscle biopsy in this setting rarely yields any useful information.
