Endocrine Abstracts

JOINT3837

Hypocalcemia induced paresthesia is a common complication in patients undergoing parathyroidectomy to treat primary hуреrраrаthyroidism (PHPT). Rarely, paresthesia can be a symptom of thyrotoxicosis. Palpation thyroiditis can occur following parathyroidectomies. It causes thyrotoxicosis in 30-40% of cases and is often asymptomatic. We present a case of patient with post-parathyroidectomy parestehesia, with normal calcemia, as a symptom of thyrotoxicosis due to palpation thyroiditis. A 51-year-old woman with a previous history of urinary calculi and osteopenia. She was diagnosed with PHPT (PTH 108 pg/ml, corrected total calcium 10.9mg/dl, phosphate and 24h urinary calcium of 474mg) a she had an abnormal left inferior parathyroid in the Tc99m sestamibi scan and ultrasound. Her pre-operative thyroid function was normal. She underwent a left inferior parathyroidectomy and discharged with calcium carbonate/cholecalciferol 1250mg/400IU daily. Two days after the procedure the patient presented to the emergency department with oral and acral paresthesia, nausea and headache. No history of recent upper respiratory tract infection, exposure to iodinated radiocontrast agents, or amiodarone use. She had a normal calcemia (PTH 18 pg/ml, serum corrected total calcium 10.2mg/dl, ionized calcium 1.27 mmol/land normal phosphate) and thyrotoxicosis (TSH 0.04 mU/l, free T4 1.62 ng/dl and free T3 3.36 ng/dl). TSH receptor (TRA), thyroperoxidase (TPOA), and thyroglobulin (TgA) antibodies were normal. The diagnosis of thyrotoxicosis due to palpation thyroiditis was made. She started propranolol 10mg tid. Her thyroid function normalized and her symptoms improved within 2 months. This is a rare case of symptomatic thyrotoxicosis caused by palpation thyroiditis in a patient that underwent parathyroidectomy for a PHPT. Operative thyroid manipulation or trauma with rupture of thyroid follicles is the most suggested mechanism. It is a self-limited condition with thyroid function normalizing within a few weeks to months. In addition, the presenting symptom was much more common in hypocalcemia a much more frequent complication of parathyroidectomy. Thyrotoxicosis is rarely associated with paresthesia, however in this case the symptoms were probably a result of the effects of thyroid hormones on the peripheral nerves. So, it is important to be aware, that in this context, not all paresthesia is a result of hypocalcemia. At 2-month follow up, the patient was asymptomatic and thyroid function studies normalized. PTT may be underestimated due to lack of symptoms and lack of routine testing, so it is important to be aware of biochemical or clinical evidence of thyrotoxicosis in the early postoperative period after parathyroidectomy.