Effects of congenital hydrocephalus on the hypothalamic gonadotrophin-releasing hormone system

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>Despite the investigations that have linked hydrocephalus to reproductive system abnormalities, no researchers have attempted to identify the pathophysiological mechanism of this relationship. Because the role of the hypothalamic gonadotrophin-releasing hormone (GnRH) system in the regulation of reproductive functions is well established, the authors used immunohistochemical and radioimmunoassay (RIA) techniques to determine the morphological and biochemical effects of hydrocephalus on the hypothalamic GnRH system.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>Hypothalamic GnRH levels, fiber density, and cell types were studied in 21- and 50-day-old control and congenitally hydrocephalic Texas rats. Results of RIA indicated a significant (8.4%) increase in GnRH in 21-day-old hydrocephalic rats (9.17 ± 0.64 pg/ng total protein) compared with that in controls (0.97 ± 0.74 pg/ng total protein). In addition, the 50-day-old hydrocephalic animals had a significantly higher level of GnRH compared with age-matched controls (20.4 pg/ng compared with 1.88 ± 2.1 pg/ng total protein). This increase was accompanied by changes in the fiber appearance and a shift from low GnRH producing cells to high GnRH producing cells in the hydrocephalic animals; however, there was no significant difference in the fiber density between the control and hydrocephalic animals at 21 days. In addition, poor neurological scores correlated with the severity of hydrocephalus.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>These results demonstrated that hypothalamic GnRH levels are significantly affected by fetal-onset hydrocephalus and that the mechanisms responsible for these effects may take place at the cellular rather than the gross structural level. Furthermore, they suggest that impairments in the GnRH system may be protracted in neonates and infants with hydrocephalus, and thus may be overcome by relatively early treatment with ventricular diversion. However, the clinical implications of GnRH perturbations in shunt-dependent patients must await a forthcoming study in shunted animals.</jats:p></jats:sec>

Neonatal Brain Hemorrhage (NBH) of Prematurity: Translational Mechanisms of the Vascular-Neural Network

“…However there is often an improvement of the reproductive cycle, following shunting [286]. Following experimental hydrocephalus in rats, increased hypothalamic GnRH was also observed [288]. …”

Swedish cohort study found that half of the girls with shunted hydrocephalus had precocious or early puberty

“…To the best of our knowledge, the present study is the first to report pubertal development in a large, and unselected population-based cohort of girls with infantile hydrocephalus. 19 The main findings TA B L E 1 Clinical data for girls with and without myelomeningocele. were the high occurrence of precocious or early puberty, and the association of early puberty and repeated shunt revisions.…”

“…17 Little information is available on the mechanism behind the effect of increased intracranial pressure on the hypothalamic-pituitary-gonadal axis, leading to early or precocious puberty. 18,19 Most earlier studies of children with hydrocephalus of other causes than myelomeningocele were performed on selected patients. [4][5][6][7]20,21 It is therefore difficult to draw conclusions regarding occurrence of precocious or early puberty, and possible risk factors for these conditions.…”

Does Ventriculoperitoneal Shunting Improve Thyroid Hormone Levels in Hydrocephalic Newborns?

“…Some papers have revealed endocrinological improvements in patients after VP shunt surgery [17,18]. Similarly, increased gonadotropin levels and a regular menstrual cycle have been reported in patients with increased ICP and pituitary hormone disturbances associated with convexity meningioma after tumor surgery [19].…”