[Hormonal diseases after traumatic brain injury]

Traumatic brain injury represents major medical and social problem in all developed countries. Its incidence is about 200 per 100,000 inhabitants per year. In the acute phase immediately after injury the posterior pituitary dysfunction is well-known. The incidence of severe grossly hypernatremic cases of diabetes insipidus (DI) is about 3%, less severe form of ADH insufficiency was recognized in 21-26%. The syndrome of inappropriate antidiuretic hormone secretion (SIADH) was described in about 14%. These changes are transient in most cases, persisting DI has an incidence of 5-7% and SIADH cases recover almost always. Since the beginning of this century several series evaluating prospectively all patients after moderate to severe TBI have been published. Permanent hypopituitarism was found in one quarter to one half of them. The most common turned out to be the growth hormone (17.6%) and gonadotropic (13.4%) deficiency. Less common is the corticotropic (8.4%) and thyrotropic (4.3%) insufficiency. In the majority of patients an isolated dysfunction was discovered. However, in 9%, a combined failure of two or more HPA axis was present. This paper describes the minimum investigation needed to diagnose hypopituitarism by patients after TBI, who may profit from substitution therapy.