The gonadotrophins response to GnRH test is not a predictor of neurological lesion in girls with central precocious puberty

Objectives: To assess the value of gonadotrophin releasing hormone (GnRH) stimulation test in identifying intracranial abnormality in girls with central precocious puberty (CPP). Patients and methods: A study of 67 girls diagnosed with CPP who underwent cranial MRI scans. Patients were not receiving any therapy and there were no neurological signs or symptoms at presentation. Patients underwent evaluation of GnRH stimulation test and plasma oestradiol levels at presentation. Results: Mean age at onset of puberty was 6.2 years (range 2.0 to 8.0 years). Intracranial abnormalities were present in 10 (15%) patients, while 57 girls (85%) had no abnormalities. No significant difference was shown between girls with intracranial abnormality and girls without intracranial abnormality in basal LH or FSH values, peak LH or FSH values, LH/FSH peak ratios, peak LH/basal LH ratios, peak FSH/basal FSH ratios at presentation. Conclusion: GnRH stimulation test does not identify those with underlying intracranial abnormality at presentation. MRI imaging remains necessary in all cases of central precocious puberty in girls.