Ultraviolet light absorption in normal and in pathological cerebrospinal fluids.

Ultraviolet spectrophotometric studies were described in 402 cerebrospinal fluids (CSF's). Normal specimens exhibited a hyperbolic curve with end-absorption but no selective absorption. In CSF's of neurologically normal hospital patients absorption maxima were found, possibly dependent upon moderate increase of proteins (PR). In centrifuged meningitis samples peaks were demonstrated, scattered over the spectral region investigated. Fifteen per cent of the CSF's in this group exhibited absorption curves similar to the normal. In contrast, all but 2% of the poliomyelitis specimens exhibited absorption bands. The distribution of the maxima was compact; none under 2500 Å., and the vast majority in the middle zones from 2600 to 2900 Å., caused in part probably by nucleic acid (NA) and PR, or their derivatives. The samples of neurosyphilis, miscellaneous neurological, and psychotic cases exhibited a variety of absorption bands. In degenerative processes also selective bands suggesting some steroid compounds appeared. Some special features of ultraviolet spectrophotometry of the CSF were discussed. The described technique supplemented by chemical methods and applied critically may be a useful tool in clinical laboratory work.