Cholinesterases of cerebrospinal fluid; data for normal fluids and fluids from patients with syphilis, meningitis, or poliomyelitis.

Abstract

In confirmation of the work of others it has been shown that the principal enzyme in human cerebrospinal fluid that can hydrolyze acetylcholine is true cholinesterase. There is in addition a lesser quantity of pseudocholinesterase. The true cholinesterase, but not the pseudocholinesterase, was found to be significantly increased in the spinal fluids of patients with syphilis, while the pseudocholinesterase, and not the true cholinesterase, was increased in the fluids of patients with either meningitis or poliomyelitis. The true cholinesterase activity was correlated neither with the protein concentration nor with the cell count, while the pseudocholinesterase was correlated with the protein concentration and less significantly with the cell count. When correction was made for the correlation between cell count and protein concentration, the correlation between pseudocholinesterase activity and protein concentration remained statistically significant, but that between pseudocholinesterase and cell count became of dubious significance. In pathological conditions it appears unlikely that either true cholinesterase or pseudocholinesterase is derived from the white cells in the fluid. It is possible that the increased pseudocholinesterase comes from the blood plasma as a result of an increase in the permeability of the "plasma–spinal fluid barrier" and that the increased true cholinesterase comes from the substance of the brain or spinal cord. For the pathological conditions studied, the determination of true and pseudocholinesterase activity of the spinal fluid would be of little value as a diagnostic aid.