Reconsidering idiopathic CK-elevation.

This study investigated the frequency of persisting, idiopathic creatine-kinase (CK)-elevation, how often the cause of idiopathic CK-elevation could be clarified, and the most frequent causes of idiopathic CK-elevation. Among 28 patients with previously idiopathic CK-elevation, CK remained elevated in 32%. The cause of idiopathic CK-elevation could be determined in 46%. Causes were mitochondriopathy (n = 5), seizure (n = 2), stroke (n = 2), myositis (n = 1), intramuscular-injection (n = 1), alcohol myopathy (n = 1), and pravastátin myopathy (n = 1). In 10 of these patients CK was normal at follow-up. CK-elevation remained idiopathic in 54%. Idiopathic CK-elevation should be comprehensively re-evaluated, even if CK is only slightly elevated or normal at follow-up.