Relationship between Acidity and Swelling in the Brain

Abstract

Measurement of pH of the brain tissue, macroscopic observation of the brain volume and pathohistological examination were made upon a total of 86 brains removed at autopsy. The causes of death were various and the brains were without macroscopical pathological changes. The values of pH ranged from 5.58 to 7.01; in the majority of cases, they were between 6.2 and 6.6. No definite relationship was found between the pH values, the cause of death, age, sex and postmortem interval. All 12 cases with a pH less than 6.0 showed remarkable brain swelling. Five out of these 12 cases died after attempts at artificial respiration or resuscitation. In 11 brains out of 55 cases with a pH between 6.0 and 6.6, remarkable swelling was seen in 4 cases and slight one in 7 cases. The prominent finding noted in the swollen brain was edema of the white matter. This was in parallel with the degree of swelling and the value of pH in all cases except one case of CO poisoning. From the above results, the author inferred that the brain swelling was due to edema of the white matter caused by acidosis and sustained insufficiency of circulation.