Pituitary Hypoplasia Is the Best MRI Predictor of the Severity and Type of Growth Hormone Deficiency in Children With Congenital Growth Hormone Deficiency

Abstract

Abstract Background and Objectives: Congenital idiopathic growth hormone deficiency(GHD) is associated with various MRI abnormalities, including both sellar anomalies such as pituitary hypoplasia, ectopic pituitary, empty sella and abnormalities of the pituitary stalk and extrasellar abnormalities such as Arnold Chiari malformation, corpus callosum agenesis, arachnoid cyst, septum pellucidum agenesis, enlarged ventricles, vermis dysplasia, and sphenoid cyst. However, it remains contentious whether MRI brain findings could provide an additional avenue for precisely predicting the differentiation of GHD based on severity(severe or partial) and type(isolated GHD or multiple pituitary hormone deficiency MPHD). This study aimed to ascertain the abnormality that is the best predictor of severe GHD and type of GHD amongst the different MRI findings. Methods: This was an analytical cross-sectional study conducted from 2018-2020. During the study period, we included a total of 100 subjects diagnosed to have idiopathic GHD after the exclusion of syndromic causes, system illness, presence of pituitary mass, and those with h/o cranial irradiation. Patients were divided into severe GHD and partial GHD based on peak stimulated GH of <5 ng/dl and ≥ 5 ng/dl respectively and into groups based on isolated GHD and MPHD. Patients were further divided into groups based on the presence of pituitary hypoplasia,extrasellar brain abnormalities (EBA), and presence of ectopic posterior pituitary and/or pituitary stalk abnormalities(EPP/PSA), respectively. Analyses were performed using SPSS version 24.0 software. Results: Amongst 100 subjects with idiopathic congenital GHD, 66 (66%) subjects had Isolated GHD while the remaining 34 (34%) had MPHD. 71 had severe GHD, and 29 had partial GHD. Amongst the MRI findings, pituitary hypoplasia was the most common finding observed in 53% of patients, while 23(23%) had EBA, and 25(25%) had EPP/PSA. Pituitary hypoplasia was observed to be the best predictor of severity of GHD with an odds ratio(OR) of 10.8 (95% CI 3.38-29.6) followed by ectopic posterior pituitary /pituitary stalk abnormalities (OR =2.8, 95% CI 1.5-9.5) while the presence of extrasellar abnormalities was the weakest predictor (OR =1.8, 95% CI 1.05-3.2). Pituitary hypoplasia was the only finding to significantly predict MPHD (OR=9.2). On ROC analysis, a Pituitary height SDS of -2.03 had a 73.2 % sensitivity and specificity of 79.3%(AUC =0.787,95% CI 0.7-0.873) for severe GHD and a sensitivity of 88.2 % and specificity of 66.7% (AUC =0.745, 95% CI 0.68-0.877) for MPHD. Conclusion: We observed Pituitary hypoplasia to be not only the most frequent MRI abnormality but also the best predictor of severe GHD and MPHD amongst various sellar and extrasellar abnormalities.