A 64-year-old Caucasian female who is 4 weeks status post total parathyroidectomy with forearm gland insertion presents to the general surgeon for her post-operative checkup. She states that her mouth feels numb and she feels “tingly all over. The surgeon suspects the patient has hypoparathyroidism secondary to the parathyroidectomy with delayed vascularization of the implanted gland. She orders a Chem 20 to determine what electrolyte abnormalities may be present. The labs reveal a serum Ca++ of 7.1 mg/dl (normal 8.5 mg/dl-10.5 mg/dl) and phosphorous level of 5.6 mg/dl (normal 2.4-4.1 mg/dl).

Hypoparathyroidism occurs when there is destruction of the parathyroid glands (autoimmune, surgical), abnormal parathyroid gland development, altered regulation of PTH production, or impaired PTH action. The acute manifestations of hypoparathyroidism (postsurgical hypoparathyroidism) are due to acute hypocalcemia.  The hallmark of acute hypocalcemia is tetany, which is a disorder of neuromuscular irritability. The symptoms of tetany may be mild (perioral numbness, paresthesia of the hands and feet, muscle cramps) or severe (carpopedal spasm, laryngospasm, and focal or generalized seizures, which must be distinguished from the generalized tonic muscle contractions that occur in severe tetany). The classic physical findings in patients with neuromuscular irritability due to latent tetany are Trousseau’s and Chvostek’s signs.