Parathyroidectomy improves neurocognitive deficits in patients with primary hyperparathyroidism

Clinical guidelines for the treatment of primary hyperparathyroidism (pHPT) often suggest parathyroidectomy, but generally fail to consider neurocognitive and psychiatric symptoms because of the relative paucity of evidence. In this prospective study, patients with pHPT (PTX) and benign euthyroid thyroid disease (THY) referred for operation were evaluated pre- and postoperatively with validated psychometric and neurocognitive instruments to determine whether learning, memory, or concentration improved with after parathyroidectomy. Statistical comparisons between groups were performed with univariate analysis and repeated measures of analysis of variance. Fifty-five subjects, mean age of 54 years, were evaluated preoperatively; 41 returned postoperatively. There were no significant differences between groups by age and gender. PTXs reported more depression symptoms preoperatively ( P = .04) that improved postoperatively. There were no differences between the 2 groups on verbal memory and trait anxiety. For PTXs, average preoperative serum calcium concentration (11.3 mg/dL) and serum PTH level (100 pg/mL) normalized postoperatively. Preoperatively PTXs showed greater delays in their spatial learning ( P = .03). All subjects learned across the 5 trials, but PTXs were more delayed ( P = .03). After operation, PTXs improved and functioned at a level equivalent to the THYs. There was an interaction between trial (neurocognitive testing), visit (pre- vs postoperative), status (PTX vs THY), and change in PTH level ( P = .06), suggesting that individuals with greater change in PTH were more likely to improve in their learning efficiency postparathyroidectomy. PHPT may be associated with a spatial learning deficit and processing that improves after parathyroidectomy. While longer-term follow-up is necessary, neurocognitive symptoms perhaps should be considered as criteria for parathyroidectomy.