Endocrine Abstracts

Background: Papilledema and raised intracranial pressure has been reported frequently in patients with hypoparathyroidism but very rarely optic neuritis (1).

Clinical case: We report a case of 63-year-old male who presented to ophthalmology with right-sided visual loss and a relative afferent pupillary defect. He was diagnosed with optic neuritis and underwent MRI brain which showed bilateral white matter changes with the possibility of demyelination. He was initially diagnosed with relapsing-remitting multiple sclerosis by the neurologist but was later found to have severe hypocalcaemia (adjusted calcium 1.32 mmol/l (2.20–2.60)) and idiopathic primary hypoparathyroidism (PTH<0.3 pg/ml (1.6–7.2)). Cerebrospinal fluid examination was entirely normal with negative oligoclonal bands. The initial MRI changes were thought to be secondary to severe hypocalcaemia as per neuroradiology MDT and subsequently, the diagnosis of multiple sclerosis was reversed. Although the underlying mechanism is not very clear, we believe there is an association between optic neuritis and primary hypoparathyroidism, especially in the absence of any other underlying cause for optic neuritis.

Conclusion: Although rare, but primary hypoparathyroidism can present as optic neuritis. Therefore, serum calcium should be checked in patients with no clear cause of optic neuritis.

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