Cholinergic enzymatic activity of cerebrospinal fluid of patients with various neurologic diseases.

The cerebrospinal fluid (CSF) of normal humans contains both true and pseudocholinesterases and choline acetyl transferase (choline acetylase) detectable by radiochemical assay. Elevations of total cholinesterase, pseudocholinesterase, and true cholinesterase occur in brain tumors, meningitis, Guillain-Barre disease, hydrocephalus, and brain abscess. However, the non-specificity and inconstancy of CSF cholinesterase changes in neurologic diseases limit its clinical usefulness. Choline acetylase levels in CSF are normally 0.187 * 0.073 nmoles ACh/ml CSF/ min. One patient with meningioma had a level of 0.680. Unlike cholinesterase, choline acetylase levels in blood are lower than in CSF. Hence, the origin of elevated CSF choline acetylase activity is probably in the nervous system.