Hypothalamic pituitary function in brain death patients--from blood pituitary hormones and hypothalamic hormones

According to the report of the Health and Welfare Ministry's research committee on brain death (1985), "brain death is defined as an irreversible cessation of the total brain function including brain stem." However, in brain death patients, whether the hypothalamic function which belongs to the brain stem function has completely ceased or not is unknown. In order to evaluate the hypothalamic function in brain death patients, the blood levels of the pituitary hormones and hypothalamic hormones were measured, and anterior pituitary stimulation test with triple bolus injection (TRH 500 micrograms, LH-RH 100 micrograms, regular insulin 0.3-0.7 unit/kg) was performed. The subjects were 13 brain death patients whose clinical states fully satisfied the criteria proposed by the committee. 1) The average blood levels of anterior pituitary hormones in these brain death patients were within normal range, and that of growth hormone was more than the twice of the normal level. 2) The blood anterior pituitary hormones were detectable in almost all cases even several days after the diagnosis of the brain death. 3) LH reserve was maintained in three cases. FSH reserve was maintained in three cases. Prolactin reserve was maintained in two cases. TSH reserve was maintained in one case. 4) Blood ADH (antidiuretic hormones) were detectable in 7 cases out of 9 cases. The blood ADH level of one case, in particular, was rather high (above 10 pg/ml). 5) Histopathologically anterior pituitaries were examined in three autopsy cases. The central necrotic areas were observed in all cases, but normal pituitary tissues existed peripherally. And all anterior pituitary hormones could be recognized immunohistochemically. 6) The blood levels of the hypothalamic hormones (GRF, CRF, LH-RH) were measured in four cases. The hypothalamic hormones were detectable in all cases. In one case, the levels of GRF were within normal range even 9 or 15 days after the diagnosis of brain death.(ABSTRACT TRUNCATED AT 250 WORDS)