The Urinary Phenolsulphonphthalein

The classification of hydrocephalus into communicating and non-communicating types is still largely based on the dye test introduced by Dandy and Blackfan in 1914 and 1917. They used the appearance of dye in the spinal fluid after its injection into one of the lateral ventricles as the criterion. In the same papers Dandy and Blackfan described a quantitative urinary dye excretion test. They showed that in cases of hydrocephalus the amount of phenol red which is excreted in the urine in a two-hourly period after its intraventricular or intrathecal injection is less than in cases with a normal cerebrospinal fluid pathway. The excretion patterns fell into two fairly distinct groups according to whether a communication did or did not exist, though it was suggested that there might be an intermediate group with a 'partial' communication. The reduced excretion results were assumed to reflect the reduction of the available absorptive surface in the subarachnoid space. Their observations were based on a small series of cases and in only 15 of their 26 patients was the anatomical site of the blockage causing the hydrocephalus known. This work was shortly overshadowed by the introduction of pneumoencephalography with its wider application to other conditions (Heuer and Dandy, 1916; Dandy, 1919). The present study was undertaken to explore and develop the possibilities of the urinary dye excretion test in hydrocephalus, and this report is based on 165 dye tests carried out on 101 patients as shown in Table 1. In all these cases the anatomical site of the block has been ascertained, either from satisfactory pneumoencephalography or at post-mortem examination. Tests, which were unsatisfactory because of incomplete urine collection, poor urinary output or some other cause, have been excluded. Few children with a normal cerebrospinal fluid pathway have been tested; those who have been were investigated for suspected hydrocephalus. TABLE 1