Hypothalamic function in patients diagnosed as brain dead and its practical consequences

Some patients who have been diagnosed as “dead by neurologic criteria” continue to exhibit certain brain functions, most commonly, neuroendocrine functions. In this chapter, we review the pathophysiology of brain death that can lead either to neuroendocrine failure or to preserved neuroendocrine functioning. We review the evidence on continued hypothalamic functioning in patients who have been declared “brain dead,” examine potential mechanisms that would explain these findings, and discuss how these findings create additional confounds for brain death testing. We conclude by reviewing the evidence for the management of hypothalamic–pituitary failure in the setting of brain death and organ transplantation.