Changes in cognitive status after parathyroidectomy-a prospective panel study

Abstract

There has been a growing interest in the effects of primary hyperparathyroidism and parathyroidectomy on nonclassic symptoms, including impaired cognitive status. We have evaluated the cognitive status of patients with primary hyperparathyroidism before and after parathyroidectomy and to assess the impact of various factors on cognitive function during the perioperative period. During a two-year period, a panel study was conducted at our institution. The study included patients scheduled for parathyroidectomy without previous parathyroid or thyroid surgery. Basic demographic data of interest and relevant clinical data were collected. Cognitive status was assessed in interviews before surgery, one month, and six months following surgery using a Mini-Mental State Examination (MMSE). A total of 94 patients (83 females) with pHPT were included in the study, with an average age of 60.2 years. The average preoperative calcium and PTH levels were 2.98 mmol/L and 307.9 ng/mL, respectively. There was a significant improvement in MMSE score six months after parathyroidectomy (from 27.93 to 28.87, p < 0.001). Preoperatively, 7.5% of patients had a pathological MMSE score (≤ 25), and six months after parathyroidectomy, only one patient had a mild disorder. Based on the multivariable mixed effect modelling, age and lower level of education were independent predictors. There is a significant improvement in cognition following parathyroidectomy, and this improvement has stable progression up to six months after surgery. Apart from age and level of education, no other variables affect cognitive status during the perioperative period.

Keywords: Cognition; Mini-Mental State Examination; Parathyroidectomy; Primary hyperparathyroidism.