Diencephalic syndrome with long-term survival.

Infants and young children with the diencephalic syndrome exhibit a normal activity level despite profound marasmus. Investigation reveals an intracranial tumour and evidence of endocrine dysfunction. The condition is easily missed in Third World countries with a high prevalence of nutritional marasmus. The advent of computer tomography and magnetic resonance imaging has simplified diagnosis. The syndrome was diagnosed in 1981 in a boy of 20 months who had a large hypothalamic tumour. Initial endocrine studies revealed very high growth hormone levels. After radiotherapy, these levels reverted to normal for a time but have subsequently declined in keeping with a state of hypopituitarism. The boy's long-term survival has afforded an opportunity for study over eight years. During this time, growth has been slow but sustained. There has been some fall off in intellectual capacity. Characteristic features of the diencephalic syndrome are normal activity and a state of euphoria in a profoundly marasmic child. Investigation reveals the presence of an intracranial tumour and evidence of endocrine dysfunction. Though there are earlier references, the condition first came to medical attention at the annual meeting of the British Paediatric Association in 1951 when Russell described the typical features. In Third World countries where childhood marasmus is common, the syndrome is easily overlooked. The present report concerns a boy who has been closely followed for more than eight years.