Effect of Hyperpyrexia,Produced by Baths,on Permeability of the Meninges.

It has been previously demonstrated that after sodium bromide is given by mouth for 5 days, a comparison of the bromide found in the blood and spinal fluid shows about 3 times as much bromide in the blood as in the spinal fluid. In certain pathological states of the nervous system this ratio shows a characteristic change. It was concluded that this method gives us a reliable method of estimating changes in permeability.

We used Malamud's 1 modification of Walter's 2 technique on patients whose mouth temperatures had been raised to 103°–106° F. for at least 30 minutes daily for at least 5 consecutive days. The patients were put into an ordinary bath tub or, more comfortably, into a continuous bath tub, the temperature of the bath being gradually raised to 110° F.

The following examples will illustrate the range of the permeability quotient.

Conclusions: The ratio of bromide in blood and spinal fluid is changed after fever. This hyperpyrexia must be greater than 103° F., continued at least 30 minutes and be repeated at least 5 successive days. The permeability quotient (P. Q.) in all cases was lowered, showing increased permeability. The maximum lowering was a P. Q. of 1.6; the least result was 2.7. A lower temperature than 103° F. or one continued for less than 5 days produced uncertain results.

The above results indicate that a hyperpyrexia produced by hot baths is capable of lowering the permeability quotient in the same manner as does the malarial fever.