ACOMMON expression of the disease process in an organ is the spilling of large amounts of normally intracellular enzymes into the circulation. For example, increased serum activity of creatine kinase (CPK) and aldolase, two soluble cytoplasmic enzymes of muscle and brain, has diagnostic and prognostic significance in skeletal or cardiac muscle disease, particularly myopathies and myocardial infarction, or both.1,2 Recent reports indicate that increases of the activity of these enzymes can also occur in the serum of some patients with such neurologic and psychiatric disorders as brain trauma, cerebral vascular disease, encephalitis, meningitis, and acute psychosis.3-10
Three of the latter studies particularly relevant to the investigations reported here. Schiavone and Kaldor found elevated serum CPK activity in 60% of 109 patients with cerebral dysfunction, including nine of 24 cases of schizophrenia.4 Bengzon et al, after finding an elevation of serum alkaline