Abraham A, et al. - Because the European Federation of Neurological Societies (EFNS) redefined elevated creatine kinase (CK) levels as 1.5 times the upper limit of normal, researchers analyzed the sensitivity and specificity of CK testing for neuromuscular disorder diagnosis. For 234 patients with neuromuscular disorders, they retrospectively extracted demographics and CK levels from an electronic database. According to results, EFNS cut-off values significantly decrease CK sensitivity for neuromuscular disorders diagnosis. While a neuromuscular disease can not be excluded by low CK values, values > 1,000 IU/l are linked to a high probability of myopathy.