Clinical and diagnostic approach to patients with hypopituitarism due to traumatic brain injury (TBI), subarachnoid hemorrhage (SAH), and ischemic stroke (IS)

The hypothalamic-pituitary dysfunction attributable to traumatic brain injury (TBI), aneurysmal subarachnoid hemorrhage (SAH), and ischemic stroke (IS) has been lately highlighted. The diagnosis of TBI-induced-hypopituitarism, defined as a deficient secretion of one or more pituitary hormones, is made similarly to the diagnosis of classical hypopituitarism because of hypothalamic/pituitary diseases. Hypopituitarism is believed to contribute to TBI-associated morbidity and to functional and cognitive final outcome, and quality-of-life impairment. Each pituitary hormone must be tested separately, since there is a variable pattern of hormone deficiency among patients with TBI-induced-hypopituitarism. Similarly, the SAH and IS may lead to pituitary dysfunction although the literature in this field is limited. The drive to diagnose hypopituitarism is the suspect that the secretion of one/more pituitary hormone may be subnormal. This suspicion can be based upon the knowledge that the patient has an appropriate clinical context in which hypopituitarism can be present, or a symptom known as caused by hypopituitarism. Hypopituitarism should be diagnosed as a combination of low peripheral and inappropriately normal/low pituitary hormones although their basal evaluation may be not distinctive due to pulsatile, circadian, or situational secretion of some hormones. Evaluation of the somatotroph and corticotroph axes require dynamic stimulation test (ITT for both axes, GHRH + arginine test for somatotroph axis) in order to clearly separate normal from deficient responses.