PITUITARY-FUNCTION IN CHILDREN WITH HYDROCEPHALUS BEFORE AND AFTER THE FIRST SHUNTING OPERATION

Objective: Children with shunted hydrocephalus experience slow linear growth in prepuberty, accelerated pubertal maturation and a reduced fi nal height. A substantial proportion of these patients have a poor gro wth hormone (GH) response to stimulation and reduced pituitary volume. The basic mechanisms behind these phenomena are still unknown, but on e can hypothesize that an unphysiological intracranial pressure (ICP) may be involved. This study was undertaken to investigate the effect o f increased ICP on pituitary function. Design: Twenty-one children (ni ne males) aged 4 months to 15 years were evaluated for pituitary funct ion before and after their first shunting operation. Methods: A clinic al examination was performed, bone age was determined and a combined p ituitary stimulation test was performed to evaluate GH, luteinizing ho rmone, follicle-stimulating hormone, cortisol, thyrotropin and prolact in secretion. Results: GH concentrations were significantly higher 10 and 15 min before the operation (P=0.04 and P=0.03 respectively) than after it. The basal levels of insulin-like growth factor-I (IGF-I) ten ded to be higher before the operation than afterwards and those of its binding protein-3 (IGFBP-3) were significantly so (P<0.01). Conclusio ns: The higher GH response to GH releasing hormone and circulating IGF BP-3 levels in children with hydrocephalus before compared with after their first shunting operation raise the possibility that the reduced GH secretion and retarded linear growth observed in children with shun ted hydrocephalus may be a consequence of decreased ICP and/or the lac k of physiological pressure variations.