Selective growth hormone deficiency of hypothalamic origin following severe head injury

The relationship between severe head trauma (SHT) and pituitary hormone deficiencies was first reported by Cyran in 1918 (1). Diabetes insipidus is the endocrino-. pathy most commonly found following head injury (2). Involvement of other pituitary hormones has been described (3) and SHT may result in selective anterior pituitary insufficiency. To date, only one case of selective growth hormone (GH) deficiency of pituitary origin due to SHT has been published (4). We present the case of a boy who developed selective GH failure following closed cranial trauma, which was characterized by a pattern of GH release of hypothalamic growth hormone-releasing hormone (GHRH) deficiency. A four-year-old boy suffered a SHT which resulted in several right-sided parietotemporal fractures. The boy remained in a coma of the third degree for three days. At that time his height was 98.5 cm (25th centile); his preceding growth rate was 6.6 cm/year. Two months later he was discharged complaining of unsteadiness (of vestibular origin) as the only clinical sequela. At the age of six years and four months he was admitted to the endocrinology ward for investigation of shortness of stature. His height was then 104.5 cm (less than third centile) and his bone age (Greulich & Pyle) was delayed by 18 months. Anterior pituitary testing by thyrotrophin-releasing hormone (300 pg. iv), gonadotrophinreleasing hormone (1 00 pg iv) and insulin-induced hypoglycaemia (0.1 units/kg iv) showed adequate TSH, cortisol and gonadotrophin responses. Basal thyroid