Prospective, randomized, controlled trial of parathyroidectomy versus observation in patients with "asymptomatic" primary hyperparathyroidism.

Background: Disruptions in cognitive function have been described in the constellation of symptoms associated with "asymptomatic" primary hyperparathyroidism (PHPT). The aim of this study was to determine the impact of parathyroidectomy (PTX) on brain function and sleep in "asymptomatic" PHPT patients.
Methods: We conducted a prospective, randomized trial comparing immediate PTX with observation in patients with asymptomatic PHPT. We performed functional magnetic resonance imaging (fMRI) of the brain, sleep assessment, and validated neuropsychological battery at baseline, 6 weeks, and 6 months. Wilcoxon rank-sum and Pearson and Spearman correlations were used.
Results: A total of 18 patients were randomized. Subjective sleepiness correlated with worse performance on executive function tests during fMRI at 6 weeks (Pearson, -0.473; P = .047) and 6 months (Pearson, -0.673; P = .002). Total sleep time correlated with PTH levels at both 6 weeks (Pearson, 0.518; P = .048) and 6 months (Pearson, 0.567; P = .018). At 6 weeks, hypersomnolence as measured subjectively was decreased in the PTX group, but increased in those observed (-2.56 vs 2.22; P = .03)
Conclusion: This prospective, randomized trial for asymptomatic PHPT patients demonstrated an association of sleep with brain function. Sleep seemed to be an indicator of brain activation in the anterior cingulate gyrus and precentral cortex. Subjective sleepiness was associated with executive function. The results of this pilot study suggest that decreased serum PTH levels correlate with improved sleep and that PTX decreases sleepiness in patients with asymptomatic PHPT.