The Prevalence of Neuroendocrine Deficits after TBI of Any Severity
In prior posts we have discussed the importance of evaluating possible neuroendocrine deficits, principally hypopituitarism, after a traumatic brain injury (TBI).
The pituitary gland is a pea-sized gland that sits in a rigid bony enclosure called the sella turcica, while the fragile pituitary stalk attaches it to the hypothalamus. Rapid brain movement from impacts can cause the brain to shift, stretching, twisting, or tearing the delicate stalk – resulting in abnormal hormone production.
As we have previously discussed, with reference to the literature, the most common chronic pituitary hormone deficit after TBI is growth hormone deficiency (GHD). Patients with GHD may present with significant fatigue, poor sleep, cognitive dysfunction, decreased exercise tolerance, reduced muscle mass and strength, dyslipidemia, anxiety, depression, and osteoporosis. It was initially thought that these deficits only appeared following moderate to severe TBI and were not common. This has proven to be inaccurate, a misunderstanding caused in part by inadequate screening – the most common screening test for GHD, the IGF-1 blood test, has been shown to lack specificity and sensitivity for the diagnosis of GHD in the TBI population. As discussed in prior posts, the only reliable means of assessing GHD in this population is “dynamic” testing such as the glucagon stimulation test (also sometimes referred to as “provocative” testing or “stimulation” testing.) Read More