A controlled, prospective study of neuropsychological outcomes post parathyroidectomy in primary hyperparathyroid patients

Background There is an increasing number of primary hyperparathyroidism (PHPT) patients with neuropsychological or psychiatric symptoms. Many of these patients do not have osseous or renal complications to satisfy the criteria for parathyroidectomy according to the NIH guidelines. Objective To assess whether there is any improvement in neuropsychological and mood symptoms following parathyroidectomy. Patients and Design Twenty PHPT patients undergoing parathyroidectomy and 20 orthopaedic controls matched for age, gender and estimated intelligence were subjects to pre and postoperative assessment of cognition and mood with a mean surgery-retest interval of 3 months. Results Using two tests of attentional flexibility [the Stroop test, the Digit symbol test of the Wechsler Adult Intelligence Scale - Revised (WAIS-R)], and two memory tests for prose and nonverbal material, no significant change was found between the groups when comparing scores before and after surgery. There was no improvement between pre and postoperative measures of verbal (dominant hemisphere) as opposed to visuo-spatial (nondominant hemisphere) function when compared to controls. There was no relationship between the reduction in serum calcium and the change in the neuropsychological measures postoperatively. Conclusion This controlled, prospective study demonstrates no significant improvement in neuropsychological indices using objective, validated psychometric tools in an unselected cohort of PHPT patients. No relationship was found between serum calcium level and the degree of neuropsychological deficit. More studies are needed to assess whether the effect of parathyroidectomy is beneficial and sustainable in PHPT patients with neuropsychological symptoms alone.