Endocrine Abstracts

We present a case of a 54-year-old man who was urgently referred to A&E by his general practitioner with very low calcium of 1.32 mmol/l (normal 2.20–2.60 mmol/l). His only past medical history of note was of recently diagnosed multiple sclerosis (MS), which presented as optic neuritis six months ago. His initial investigations included high phosphate level of 2.0 mmol/l (normal 0.8–1.5), normal vitamin D levels (76 mmol/l) and a very low 24-hour urine calcium of less than 2.2 mmol/24 hours (normal 2.5–7.5). His PTH levels were undetectable i.e. <0.3 pg/ml (normal 1.6–7.2), confirming primary hypoparathyroidism. As no underlying cause was found, this was labelled as idiopathic hypoparathyroidism. Calcium was replaced intravenously initially and the patient was discharged on oral calcium supplements, aiming to keep the calcium in the lower normal range. Interestingly, after noting his new diagnosis of primary hypoparathyroidism, neurologists reviewed their earlier diagnosis of MS. As his lumbar puncture results were normal including negative oligoclonal bands, his MRI scan which had shown generalised white matter changes, was discussed in neuroradiology MDT, who thought that these changes were likely secondary to chronic hypocalcaemia rather than MS. Therefore the diagnosis of MS was reversed. Although papilloedema and raised intracranial pressure have been reported with hypoparathyroidism in the literature, optic neuritis has been very rarely reported, (1) however there could be an association between the two conditions.

Reference: 1. Bajandas FJ, Smith JL. Optic neuritis in hypoparathyroidism. Neurology 1976 26 (5) 451–454.