MR of the pituitary in patients with Prader-Willi syndrome: Size determination and imaging findings
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Prader-Willi syndrome (PWS) is an unusual genetic disorder characterized by short stature, obesity, hypogonadism, hypotonia, cognitive impairment, and dysmorphic facies. There is an interstitial deletion of the proximal long arm of chromosome 15 in about 70% of patients. Some of these clinical features suggest a central hypothalamic/pituitary dysfunction, and recent investigations have demonstrated a marked impairment in spontaneous growth hormone (GH) secretion. We studied 15 GH-deficient PWS patients by magnetic resonance imaging (MRI) to determine whether there was a diminution in the gross morphological size of the anterior pituitary gland, the site of GH synthesis. We also set out to catalog the pertinent imaging findings in this patient population. Our results indicate that this is the first report documenting pituitary size by MRI in PWS patients. No statistically significant difference was found in the height of the anterior pituitary gland in PWS patients compared with either normal children or children with isolated GH deficiency. An interesting imaging finding is that three of 15 patients (20%) demonstrated complete absence of the posterior pituitary bright spot (PPBS), and a fourth patient demonstrated a small PPBS. These observations reflect an objective physiologic disturbance in the hypothalamus. The clinical and radiologic implications of these findings are discussed.
KeywordsGrowth Hormone Imaging Finding Hypogonadism Growth Hormone Deficiency Anterior Pituitary Gland
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- 1.Zellweger H, Soper R (1979) The Prader-Willi syndrome. Med Hyg 37:3338–3345Google Scholar
- 3.Cassidy SB (1984) Prader-Willi syndrome. Curr Prob Pediatr 14: 1–55Google Scholar
- 4.Angulo M, Castro-Magana M, Uy J (1991) Pituitary evaluation and growth hormone treatment in Prader-Willi syndrome. J Pediatr Endocrinol 4: 167–173Google Scholar
- 10.Costeff H, Holm VA, Ruvalcaba R, et al (1990) Growth hormone secretion in Prader-Willi syndrome. Acta Pediatr Scand 79:1059–1062Google Scholar
- 14.Kucharczyk J, Kucharczyk W, Berry I, et al (1988) Histochemical characterization and functional significance of the hyperintense signal on MR images of the posterior pituitary. AJNR 9: 1079–1083Google Scholar
- 15.Gudinchet F, Brunelle F, Barth MO, et al (1989) MR imaging of the posterior hypophysis in children. AJNR 10: 511–514Google Scholar
- 18.Ruvalcaba RH, Holm VA (1993) Effects of growth hormone in Prader-Willi syndrome. Clin Pediatr 32: 292–295Google Scholar