Abstract
By means of liquid chromatography we investigated free amino acids in cerebrospinal fluid (CSF) (161 subjects) and in plasma (138 subjects) in various neurological diseases and in controls. A general increase in CSF amino acids was found in Group C (samples exhibiting both pleocytosis and increasing CSF protein concentration) and in “spinal canal block” and “neuro-Behget's syndrome”. Also, some abnormalities were detected in these groups with regard to changes in CSF cells, protein or IgG%. In the case of “Guillain-Barré syndrome” we noted an increase in CSF alanine, glycine, methionine, arginine and the branched-chain group. In “multiple sclerosis” an increase was evident in CSF alanine, in plasma alanine and arginine, and in the plasma: CSF ratio of tyrosine. In patients of “motor neuron diseases (MND)” CSF glutamic acid, alanine, histidine and arginine all indicated an increase, along with the plasma: CSF ratio of tyrosine. In Group C and in “neuro-Behget's syndrome” glycine, methionine and lysine were lowered in the plasma: CSF ratio. Also, the ratio of valine in the former and histidine in the latter indicated a decrease. These results can be supposed to reflect either biochemical abnormalities of plasma and/or the CNS, or changes in the transport systems of the blood-brain barrier.
