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 AcquisitionThe 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). ResultsWe 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. ConclusionHypopituitarism is a common complication of both traumatic brain injury and aneurysmal subarachnoid hemorrhage and might contribute to morbidity and poor recovery after brain injury.

Incidence and prevalence of hypopituitarism are estimated to be 4.2 per 100,000 per year and 45.5 per 100,000, respectively. Although the clinical symptoms of this disorder are usually unspecific, it can cause life-threatening events and lead to increased mortality. Current research has refined the diagnosis of hypopituitarism. Identification of growth hormone and corticotropin deficiency generally requires a stimulation test, whereas other deficiencies can be detected by basal hormones in combination with clinical judgment. Newly developed formulations of replacement hormones are convenient and physiological. Work has shown that many patients with brain damage--such as traumatic brain injury or aneurysmal subarachnoid haemorrhage--are at high risk of (sometimes unrecognised) hypopituitarism. Thus, a much increased true prevalence of this disorder needs to be assumed. As a result, hypopituitarism is not a rare disease and should be recognised by the general practitioner.

Introduction: Remission criteria of acromegaly are based on biochemical variables, i.e., normalization of increased hormone levels. However, the established reduction in Quality of Life (QoL) is suggested to be independent of biochemical control. The aim of this study was to test which aspects predict QoL best in acromegaly.Methods/design: This is a prospective cohort study in 80 acromegalic patients, with a cross-sectional and longitudinal part. The main outcome measure was health-related QoL, measured by a generic and a disease-specific questionnaire (the SF-36 and AcroQoL). Main predictors were age, gender, biochemical control, disease characteristics, treatment modalities, and psychopathology.Results: Our cohort of 80 acromegalics had a mean age 54.7 ± 12.3 years with an average disease duration of 10.8 ± 10.0 years. Ratio macro-/microadenoma was 54/26. In adjusted mixed method models, we found that psychopathology significantly predicts QoL in acromegaly (in models including the variables age, gender, disease duration, tumor size, basal hormone levels, relevant treatment modalities, and relevant comorbidities), with a higher degree of psychopathology indicating a lower QoL (depression vs. AcroQoL: B = −1.175, p < 0.001, depression vs. SF-36: B = −1.648, p < 0.001, anxiety vs. AcroQoL: B = −0.399, p < 0.001, anxiety vs. SF-36: B = −0.661, p < 0.001). The explained variances demonstrate superiority of psychopathology over biochemical control and other variables in predicting QoL in our models.Discussion: Superiority of psychopathology over biochemical control calls for a more extensive approach regarding diagnosing depression and anxiety in pituitary adenomas to improve QoL. Depressive symptoms and anxiety are modifiable factors that might provide valuable targets for possible future treatment interventions.

Sonic hedgehog (Shh) is a signaling protein that binds to Patched and mediates its effects through Gli transcription factors. Shh is important in regulating survival and growth in both the embryo and the adult. It is known to be involved in pituitary development, but its role in the adult pituitary has not been investigated. Here, we show Shh and Gli1 immunoreactivity in adult human corticotroph cells. Administration of Shh (5 microg/ml) alone and in combination with corticotrophin-releasing hormone (CRH; 100 nM) in dispersed rat anterior pituitary and AtT-20 mouse corticotrophinoma cells increased corticotrophin (ACTH) secretion and pro-opiomelanocortin (POMC) promoter activity. Shh and CRH act additively in increasing CRH receptor 1 (CRH-R1). Unexpectedly, we found that CRH on its own increased Gli-dependent transcription, which in turn stimulated POMC transcription. Gli1 is necessary for CRH signaling, since knocking down Gli1 by RNA interference abolished the stimulatory effect of CRH on POMC. Taken together, our results demonstrate a new role for Shh and Gli1 in corticotroph function and provide a new link between Shh and CRH signaling pathways.