Electrodiagnosis and muscle biopsy in asymptomatic hyperckemia

Purpose/aim of the study: An increased serum level of creatine kinase (CK) in asymptomatic individuals is a diagnostic challenge, as it may be associated with either physiological conditions, such as exercise or even signal an ominous neuromuscular disease at a presymptomatic stage. The electromyogram (EMG) and the muscle biopsy play a key role in the evaluation of asymptomatic hyperckemia. The objective of this study was to investigate asymptomatic individuals with increased CK levels.

We comparatively studied EMG, quantitative EMG and muscle biopsy in asymptomatic clinically normal individuals with repeatedly increased CK levels.

Conventional EMG was abnormal in 76% of patients, while quantitative EMG showed abnormal results in 88.9%. Muscle biopsy was diagnostic in 28%, one patient had neurogenic findings, 40% showed non-specific changes and 28% had normal results.

EMG and especially quantitative EMG are highly sensitive in detecting subclinical neuromuscular diseases, whereas muscle biopsy may better contribute in the final diagnosis. No strong correlations were found between histological abnormalities and electrophysiological data, but further research is needed.