Growth hormone deficiency after traumatic brain injury in adults: when to test and how to treat?

Hypopituitarism has numerous potential causes, and it is becoming clear that traumatic brain injury (TBI), including traffic accidents and sport-related injuries, is commonly associated with pituitary dysfunction. Mechanisms of pituitary damage after TBI include direct injury and vascular problems, and more recent research suggests that autoimmunity may also be involved. There may also be a genetic influence, as the E3 allele of the ApoE gene may provide some protection from post-traumatic hypopituitarism. Studies suggest that patients with mild or moderate TBI are likely to recover pituitary function over time. In patients with severe TBI, however, adrenocorticotrophic hormone and growth hormone deficiencies may persist. Patients who experience TBI should, therefore, be followed up carefully and evaluated for pituitary dysfunction to ensure that appropriate hormone replacement therapy can be provided if needed.