LAUSR

Abstract Hypoparathyroidism, first described in 1912 by Collip has an estimated incidence of 24-37/100,000 person-years with the most common cause being anterior neck surgery. Other etiologies include infiltrate diseases like sarcoidosis, vitamin D deficiency, and heritable syndromes like autoimmune polyglandular syndrome type 1. Idiopathic hypoparathyroidism (IHPTH) is diagnosed when PTH and calcium levels are both low. The association between hypoparathyroidism and basal ganglia calcifications was first described in 1939 by Eaton. Commonly, patients with basal ganglia calcifications present with seizures. A case of IHPTH and basal ganglia calcification in a patient with a past medical history of epilepsy is described. A 33-year-old male with past medical history of epilepsy, depression, alcohol, and polysubstance abuse presented for suicidal ideations to LAC-USC ER. He reported perioral numbness and numbness and tingling in his hands and feet bilaterally. He was taking valproic acid for his seizures, but ran out. Physical exam was significant only for a positive Trousseau’s sign. CMP showed a calcium of 5.8mg/dL (n: 8.5-10.3), albumin of 3.8 g/dL, and phosphorus of 5.9mg/dL (n: 2.5-4.5). The differential diagnosis for hypocalcemia included magnesium deficiency from alcohol abuse, vitamin D deficiency, or pseudohypoparathyroidism. Additional labs showed PTH of 6 pg/mL (n: 15-65), magnesium of 1.9 mg/dL, and vitamin D 25 of 31ng/ml. The patient was diagnosed with IHPTH. Calcitriol 0.5mcg BID and calcium carbonate 1000mg TID were initiated. CT brain without contrast was obtained which showed bilateral basal ganglia and right cerebellar hemisphere calcifications. When encountering hypocalcemia, clinicians should rule-out common causes of low serum calcium values, including hypoalbuminemia, CKD, prior neck surgery, vitamin D deficiency, magnesium deficiency, pseudohypoparathyroidism as well as hypoparathyroidism. In addition, queries about the complications of a low serum calcium level should be made. Once IHPTH is diagnosed, clinicians should look for basal ganglia calcifications to assess the duration of the condition. In addition, calcifications may be evident in the cerebellum, cortical white matter and the thalamus. Studies suggest that high serum calcium-phosphorus products deposit in soft tissues, although the exact mechanism by which this product is preferentially deposited into the basal ganglia is not understood. We present this case to highlight the association between basal ganglia calcifications and idiopathic hypoparathyroidism.