The estimation of vitamin B1 in cerebro-spinal fluid

Abstract

A method is described, based upon the work of Schopfer, of estimating vit. B1 in 1-4 ml. samples of cerebro-spinal fluid. The method uses a fungus, Phyco-myces blakesleeanus, and a correction can be applied to allow for interfering substances in the fluid and so obtain approximately true values for the total vit. This is in the free unphosphorylated form in normal c.s.f. The method was applied to 272 different samples of csi. obtained from patients. The normal range is 0.0-1.3 [mu]g./100 ml., with a mean ([plus or minus] [sigma]) of 0.5 [plus or minus] 0.4. Pathological samples of fluid tend to given higher values with a mean of 2.2 [plus or minus]1.3; the values show a positive correlation with the leucocyte count, and cocarboxylase (vit. B1 diphosphate ester) may be found in pathological samples. These results are discussed in relation to other work on the metabolism of vit. B1, and are shown to agree very well with it. But because a value of zero may be found in the c.s.f. of patients who are almost certainly not deficient in the vit., the method seems to be useless for clinical purposes.