Introduction: Diagnosis of growth hormone deficiency (GHD) and idiopathic short stature (ISS) is not straightforward. Nowadays growth hormone (GH) stimulation tests play a key role in the diagnosis but they are controversial due to the lack of normative data, poor reproducibility and poor disease concordance.
The magnetic resonance imaging (MRI) is also a tool in the study of patients with short stature. Structural alterations of the hypothalamic-pituitary region have been described on brain MRI from 20 to 44% in children affected by isolated GHD (IGHD).
Aim: To know the prevalence of hypothalamic-pituitary abnormalities in patients with short stature and GH treatment indication.
Methodology: Retrospective studyof IGHD and ISS patients diagnosed in a tertiary hospital's Pediatric Endocrinology Unit from February 2013 to December 2017. It is standard of care in our unit to obtain an MRI on all patients prior to starting the GH treatment, regardless of the diagnosis.
Inclusion criteria: patients with harmonic short stature (height <-2 SD below the mean for age, sex and reference population), brain MRI with or without contrast with specific attention to the pituitary, at least one GH stimulation test and GH treatment indication.
Patients were defined as GHD if they had a peak of GH <7,4 ng/dL in response to stimulation tests (exercise, L-dopa or glucagon test).
In patients with normal or dissociated (normal and pathologic) tests, therapeutic trial with GH was indicated if height was <-2,5 SD and growth velocity <-1 SD.
Exclusion criteria: histories of cranial radiation, other hypothalamic-pituitary hormone deficiencies, previously known hypothalamic-pituitary abnormalities, chronic kidney disease and disharmonic short stature.
Results: 215 patients were included (95 girls), all the patients were diagnosed as IGHD.
|Normal pituitary region||Pituitary hypoplasia||Ectopic neurohypophysis||Pituitary cyst||Other findings*|
|IGHD (n:215)||163 (75,8%)||37 (17,2%)||2 (0,9%)||8 (3,7%)||5 (2,3%)|
|IGHD: isolated growth hormone deficiency.|
|*Other findings, i.e. Type 1 Chiari anomalies.|
One of the patients with pituitary hypoplasia also had a Type 1 Chiari anomaly.
All other findings were Type 1 Chiari anomalies.
No images of cranial tumors were found.
Conclusions: Brain MRI is helpful in the study of children with IGHD and ISS.
The prevalence of abnormalities in the hypothalamic-pituitary region in these children is higher than in general population.
The main IGHD-related brain pathology encountered was pituitary hypoplasia (17,2%).
19 - 21 Sep 2019
European Society for Paediatric Endocrinology