Endocrine Abstracts

Introduction: Hypoparathyroidism is a rare endocrine disease with a prevalence of less than 40/100,000 people worldwide¹. It has a variable presentation but can present with life-threatening arrhythmias or seizures.Case PresentationA 31-year-old male presented to our Emergency Department following a witnessed tonic-clonic seizure with no previous history of epilepsy. He was not on any regular medications and denied recreational drug use. Examination was largely unremarkable with a normal neurological examination. However, there was evidence of significant tooth hypoplasia and poor dentition. Admission blood tests showed profound hypocalcaemia (adjusted calcium level of 1.47 mmol/l) with an inappropriately low parathyroid hormone (PTH) level (1.6 pmol/l). Vitamin D was low (22 nmol/l). Full blood count, renal function, liver function and magnesium levels were normal. A CT head was unremarkable though subsequent MRI showed Chiari I malformation for which neurosurgical referral has been made. There was no history of neck surgery. He reported longstanding mild paraesthesia in his fingers but was otherwise well in himself with no evidence of tetany or spasms. He denied any previous seizures or fractures but may have had rare nocturnal cramps in his calves. He reported recurrent childhood infections, with resultant hospital admissions in his home country of Lithuania. It was suspected he may have undiagnosed learning difficulties. He had no notable family history. Given findings of severe, symptomatic hypocalcaemia secondary to hypoparathyroidism and Vitamin D deficiency, he was admitted and treated with intravenous calcium gluconate acutely. He was also commenced on Alfacalcidol and Adcal D3 which were titrated to achieve normocalcaemia. A Vitamin D loading regimen was initiated (50,000 units once a week for 6 weeks). He was discharged from hospital once his calcium stabilised >2 mmol/l. Adjusted calcium levels remain at the target lower end of the normal range on oral calcium and Alfacalcidol, with no further seizures. Genetic tests were sent for chromosomal analysis and gene panel tests.

Conclusion: It is essential to rule out calcium and other electrolyte derangements as a contributory factor for new onset seizures. Once hypocalcaemia is identified, a systematic approach is key to determine the cause of hypocalcaemia, which then allows timely treatment.

Reference: 1. Bilezikia, J. P. (2020) ‘Hypoparathyroidism’, Journal of Clinical Endocrinology and Metabolism, 105(6), pp. 1722–1736. doi: 10.1210/clinem/dgaa113.