Muscle cramps involving the lower back, legs, and feet are common in patients with hypoparathyroidism and hypocalcemia. Tetany develops if hypocalcemia is severe. In some patients, laryngospasm and bronchospasm may be life threatening. Hypocalcemia of primary hypoparathyroidism may cause extrapyramidal choreoathetoid syndromes in patients with basal ganglia calcifications. Spastic paraplegia, ataxia, dysphagia, and dysarthria have been documented in association with hypoparathyroidism-induced hypocalcemia.
Severe hypocalcemia causes papilledema, which improves with treatment of the calcium derangement.
Emotional instability, anxiety, depression, confusion, hallucinations, and psychosis have been described in patients with hypoparathyroidism when the calcium level is low. Normocalcemia corrects these conditions. Chronic hypocalcemia, as observed in primary hypoparathyroidism, also is associated with ocular cataracts, abnormal dentition, and dry, puffy, coarse skin. In severe hypocalcemia, a prolongation of the QT interval is observed on ECG, and congestive heart failure may develop. Correction of hypocalcemia reverses cardiac effects of hypoparathyroidism.