Purpose: To evaluate a non-invasive method to assess the progressivity of idiopathic central precocious puberty (CPP) by quantifying perfusion of the pituitary stalk with arterial spin labeling (ASL) and using the gonadotropin-releasing hormone (GnRH) test as a reference test to define progressive CPP.
Methods: In a single center retrospective study, 52 consecutive patients, observed between October 2015 and April 2017 and referred with early signs of puberty, were evaluated using the GnRH test and cerebral magnetic resonance imaging (MRI). Patients with peripheral or non-idiopathic puberty were excluded. The distribution of perfusion values between patients with progressive and non-progressive CPP was compared using a nonparametric Mann-Whitney U‑test.
Results: In this study 35 patients were included and 29 had progressive CPP. These patients displayed significantly higher cerebral blood flow (CBF) values than the 6 patients with non-progressive CPP (p = 0.006). The median CBF for patients with non-progressive and progressive CPP was 45.25 ml/min/100 g (interquartile range 36.9-54) vs. 65 ml/min/100 g (interquartile range 55.5-74.5), respectively. To determine if the CPP was progressive, the best CBF threshold was 55.5 ml/min/100 g with a sensitivity of 76%, a specificity of 83% and an accuracy of 77%. There were strong significant correlations between CBF and LH peak (r = 0.67, p < 0.001) and between CBF and LH/FSH peaks ratio [r = 0.71, p < 0.001] during the GnRH test.
Conclusion: Arterial spin labelling (ASL) offers a novel tool to assess the progressivity of idiopathic CPP.
Keywords: Cerebral blood flow; Children; GnRH; Hypothalamic-pituitary-gonadal axis; Pituitary stalk.