I keep hearing more and more about the need for people with TBI to see an endocrinologist to rule out hypopituitarism. Some studies I’ve read about have found improvements in cognitive outcome following the administration of growth hormone. It is hypothesized that it may be at least partially responsible for the fatigue so common after TBI. Can you shed some light on this topic?
Head injury can damage the pituitary gland and reduce production of two important hormones. The part of the pituitary gland that regulates growth hormone (GH) release is particularly vulnerable to the effects of head injury. Reduced production of GH causes symptoms of fatigue, reduced interest in sex, reduced stamina, anxiety, and depression. This happens in about 18 percent of people with brain injuries, most of whom had moderate to severe TBI. In most patients (90 percent), this condition resolves within a year.
The part of the pituitary gland that makes antiduretic hormone (ADH) is also vulnerable to injury. Reduced production of ADH can cause diabetes insipidus, which causes excessive urination and extreme thirst. (Unlike diabetes mellitus, diabetes insipidus does NOT raise blood sugar levels and is NOT treated with insulin.) Sometimes the resulting dehydration causes a sensation of fatigue. Diabetes insipidus occurs in about 25 percent of the people with brain injury, most of whom have had severe TBI. And again, in most patients, this condition resolves in less than a year.
Bazarian JJ, Cernak I, Noble-Haeusslein L, Potolicchio S, Temkin N. Long-Term Neurologic Outcomes After Traumatic Brain Injury. Journal of Head Trauma Rehabilitation. 2009; 24(6):439-451.
Dr. Bazarian is an emergency physician with a strong research interest in traumatic brain injury. He is associate professor of Emergency Medicine, Neurology, and Neurosurgery at the Center for Neural Development and Disease, University of Rochester Medical Center.