Subarachnoid hemorrhage as a cause of hypopituitarism

Common causes of pituitary insufficiency include pathologies such as pituitary adenomas, other intra- and parasellar tumors, as well inflammatory, surgical or radiation-induced destruction of pituitary tissue. More recently, hypopituitarism has also been identified as a frequent sequel of traumatic brain injury (TBI). Despite the close anatomical relationship between pituitary gland, hypothalamic structures and the arteries of the circle of Willis and the observation that many bodily and psychosocial long-term sequelae of survivors of aneurysmal subarachnoid hemorrhage (SAH) resemble those of patients with untreated hypopituitarism, aneurysmal SAH has so far been considered a rare cause of endocrine abnormalities. However, in recent clinical investigations partial hypopituitarism has been diagnosed in 37.5-55% of SAH survivors. At present, many questions concerning the most appropriate diagnostic work-up, the clinical implications of hormone deficiencies and relative importance of hormone replacement in this patient group are not yet satisfactorily clarified. This article gives an overview of the historical and current studies on hypopituitarism as a consequence of aneurysmal SAH, which show that neuroendocrine deficiency occurs more often than has so far been appreciated. Despite the still unresolved issues, endocrine abnormalities should be considered a cause for impaired recovery and long-term morbidity in SAH-survivors. Enhanced awareness of physicians treating SAH-patients for post-traumatic hypopituitarism is called for, so that screening for hormone deficiencies and appropriate replacement therapy can be initiated.