Endocrine Abstracts

A 38-year-old lady was referred to our endocrinology department with headache, elevated prolactin concentration and intolerance to cabergoline by the gynaecologist. She was found to have elevated prolactin whilst investigating for secondary amenorrhoea. She described her headaches to be worse on cough, sneezing and laughing. There was no evidence for raised intracranial pressure clinically and no visual field defect was identified. Prolactin was 3194 miu/l, however there was no galactorrhoea. An MRI head revealed a pituitary microadenoma, and as such it was felt the headaches were as a consequence of this. Treatment was initiated with cabergoline, which was poorly tolerated mainly due to persisting headaches.

Following her first visit to the endocrine clinic MRI pituitary, pituitary hormones and glucagon stimulation test was organised. She was commenced on bromocriptine and subsequently on quinagolide, both of which were presumed to be poorly tolerated due to increasing headache. She had low TSH with low free T₄ and cortisol response on Glucagon stimulation was poor. She was replaced with thyroxine, steroids and small dose quinagolide. She continued to have similar headaches but her menstrual periods were restored. A repeat MRI head was performed which failed to demonstrate any change in the size of the microadenoma, however, it did reveal a significant Arnold-Chiari malformation. Posterior decompression by the neurosurgical team resulted in dramatic improvement in the headaches. Cabergoline was restarted as it was felt the initial headache was due to the Arnold Chiari malformation. There were no side effects reported this time.

This lady clearly had dual pathology both of which could present with headaches. The diagnosis of Arnold Chiari malformation was initially missed due to the concurrent diagnosis of a pituitary microadenoma, therefore it is important to consider dual pathology if symptoms do not resolve.