Hypothalamopituitary Dysfunction Following Traumatic Brain Injury and Aneurysmal Subarachnoid Hemorrhage

CONTEXT: Neuroendocrine dysfunction following traumatic brain injury and aneurysmal subarachnoid hemorrhage may occur with a much higher prevalence than previously suspected. This sequela is a potentially serious but treatable complication of brain injury. OBJECTIVE: To review research on hypothalamopituitary dysfunction as an underdiagnosed consequence of traumatic brain injury and subarachnoid hemorrhage, the natural history of this complication, and the potential clinical and public health implications of posttraumatic hypopituitarism. EVIDENCE ACQUISITION: The MEDLINE database was searched for articles published between 2000 and 2007 using any combination of the terms traumatic brain injury or subarachnoid hemorrhage with pituitary, hypopituitarism, growth hormone deficiency, hypogonadism, hypocortisolism, hypothyroidism, or diabetes insipidus. The reference lists of articles identified by this search strategy were also searched. All articles reporting original data on endocrine outcomes after traumatic brain injury or aneurysmal subarachnoid hemorrhage in peer-reviewed journals with regard to prevalence, pathogenesis, risk factors, outcomes, and clinical course were selected. We pooled data and calculated prevalence rates and 95% confidence intervals (CIs). RESULTS: We identified 19 studies including 1137 patients. The pooled prevalences of hypopituitarism in the chronic phase after traumatic brain injury and aneurysmal subarachnoid hemorrhage were 27.5% (95% confidence interval CI, 22.8%-28.9%) and 47% (95% CI, 37.4%-56.8%), respectively. The pooled prevalence of hypopituitarism was greater in patients with severe compared with those with mild or moderate traumatic brain injury. Early neuroendocrine abnormalities were transient in some patients while, less commonly, hypopituitarism evolved over time in others. Patients with posttraumatic hypopituitarism showed an impaired quality of life and an adverse metabolic profile. CONCLUSION: Hypopituitarism is a common complication of both traumatic brain injury and aneurysmal subarachnoid hemorrhage and might contribute to morbidity and poor recovery after brain injury.