Bromide partition test in the evaluation of the blood-cerebrospinal barrier in children with congenital hypothyroidism and central nervous system disease.

Serum and cerebrospinal fluid bromide partiton was studied in 11 children with congenital hypothyroidism, in 12 children with tuberculous meningitis, and in 10 children with various neurological disorders. The ratio serum bromide per cerebrospinal fluid bromide (bromide index) was below the critical value of 1.65 in 5 of 11 children with hypothyroidism as compared with 10 of the 12 children with tuberculous meningitis. No clear correlation was found between the test and the clinical and laboratory signs of hypothyroidism. The test is a valuable index of blood-cerebrospinal fluid barrier involvement in hypothyroidism.