Phenolsulphonephthalein Absorption From the Subarachnoid Space in Paresis and Dementia Praecox

The study of absorption of dye from the subarachnoid space is not new. The use of phenolsulphonephthalein is, however, of comparatively recent origin. Dandy and Blackfan1used it in their studies of hydrocephalus. (The solution used was neutral in reaction and nontoxic. The solution prepared for kidney function tests should not be used because of its alkaline reaction.) In thirty to fifty minutes after the dye had been injected into the subarachnoid space, traces of it were found in the right lymphatic and thoracic ducts whereas the dye appeared in the blood in three and in the urine in six minutes. In two hours from 35 to 60 percent, of the dye was recovered in the urine. They conclude that the cerebrospinal fluid passes directly into the blood, and the lymph spaces are not concerned with its absorption. Shortly after the dye had been injected into the lumbar