Neuromuscular recovery after parathyroidectomy in primary hyperparathyroidism

Background. Primary hyperparathyroidism today is diagnosed in the asymptomatic phase because of the inclusion of serum calcium in sequential multichannel analysis. The purpose of present study was to test for neuromuscular abnormalities in asymptomatic patients and to test the improvement of neuromuscular performance after parathyroidectomy. Methods. Nine patients with primary hyperparathyroidism and nine patients with nodular goiter were enrolled in this study. Neuromuscular recovery including muscle power, sensation, and fine motor movement was studied before operation and 1 week and 4 weeks after operation. The muscle power was measured as grip power, palm pinch, lateral pinch, and three-chuck pinch. The sensation was measured as touch sensation and two-point discrimination. The fine motor movement was measured with the Purdue Pegboard Test and the Minnesota Manual Dexterity Test. Results. Four weeks after the operation the patients with hyperparathyroidism had increased their muscle strength and had improved fine motor movement but no change was noted in two-point and touch sensation. When the postoperative muscle recovery was compared, there was a reversible correlation (r=-0.62; p<0.05) with the preoperative muscle strength and no correlation with the preoperative serum calcium, phosphate, alkaline phosphatase, and intact parathyroid hormone levels. No such improvement was detectable among the control subjects. Conclusions. Surgery can improve muscle strength and fine motor movement but does not affect sensation in asymptomatic patients.