Growth retardation due to idiopathic growth hormone deficiencies: MR findings in 24 patients

Abstract

In this study we evaluated the pituitary-hypothalamic abnormalities of "idiopathic growth hormone (GH) deficiency" as demonstrated by MR imaging. Twenty-four patients were examined with a 1.5-T unit using spin echo T-1 weighted images. The patients were divided into two groups according to MR findings: those with ectopic posterior pituitary glands (12 patients), and those with normal posterior pituitary glands (12 patients). Ten patients in the former group and four in the latter group had small anterior pituitary glands. All patients in the former group but only four in the latter group had severe GH deficiencies. Multiple hormone deficiencies were found in eight patients in the former group, but in only two in the latter group. Among the 12 patients with posterior pituitary ectopia, 11 were males, 10 had been born by breech delivery, and four had a history of asphyxia. It is speculated that perinatal abnormalities can cause posterior pituitary ectopia and that there is a close correlation between breech delivery and the male disadvantage of posterior pituitary ectopia. Half of our patients with "idiopathic GH deficiency" had ectopic posterior pituitaries. GH deficiency with posterior pituitary ectopia should no longer be considered idiopathic because organic lesions can now be identified during life.

Final Height in Children with Idiopathic Growth Hormone Deficiency Treated with a Fixed Dose of Recombinant Growth Hormone

“…This dose is considered low according to the recommended range of international dosing; still, the FAH achieved was comparable with other studies using higher doses of rhGH. A major strength of this study is that all children were diagnosed with idiopathic GHD using stringent criteria and treated in a highly consistent manner, none had GHD due to medication or any other organic mechanism, and a large proportion demonstrated MRI abnormalities consistent with true GHD, at the same rates reported previously [20,21,22]. These factors greatly reduce the likelihood of inclusion of children with either constitutional growth delay or idiopathic short stature.…”

“…One describes idiopathic GHD as the absence of demonstrable anatomical abnormality of the pituitary-hypothalamus, while organic GHD includes either an associated anatomical pituitary defect or a brain tumor/central nervous system (CNS) insult secondary to radiotherapy or surgery [13]. The second approach is to restrict organic GHD to those with local tumor, a history of radiotherapy or chemotherapy, and to include those with a developmental anatomical abnormality of the pituitary as part of the idiopathic GHD spectrum [20,21,22]. For the purposes of this study, we chose this latter definition of idiopathic GHD.…”

Development of additional pituitary hormone deficiencies in pediatric patients originally diagnosed with isolated growth hormone deficiency due to organic causes

“…In contrast, such perinatal or neonatal conditions have been reported to be more prevalent among children with organic GHD and an initial diagnosis of MPHD (26,27,28,29), and in patients with idiopathic IGHD (4).…”

Development of additional pituitary hormone deficiencies in pediatric patients originally diagnosed with idiopathic isolated GH deficiency

“…Patients with additional pituitary deficiencies diagnosed during follow-up had a higher incidence of breech presentation, perinatal asphyxia, and neonatal complications, and a trend toward greater delivery complications. Historically, these features have been recognized as more common among children who present initially with MPHD (23,24), although they are typically associated with organic rather than idiopathic GHD (25,26). Thus, there appears to be a spectrum of severity among patients with such perinatal histories, with the most severe presenting initially with MPHD and the less severe presenting initially with IGHD and later progressing to MPHD.…”