Cognitive changes after parathyroidectomy in patients with secondary hyperparathyroidism.
BACKGROUND
Cognitive impairment was frequently reported in uremic patients with dialysis, but improvements of cognition after parathyroidectomy for symptomatic secondary hyperparathyroidism have never been reported before.


METHODS
Thirty-nine patients, who were successfully operated on with total parathyroidectomy plus autotransplantation were enrolled. Twenty-three dialysis patients, age >50 years, who had a serum level of intact parathyroid hormone (iPTH) greater than 650 pg/ml, and who did not undergo parathyroidectomy were selected as the control group. The mini-mental state examination (MMSE) and the clinical dementia rating (CDR) test were administered to all patients. Before the operation, educational level, symptoms of bone pain, skin itching, general weakness and insomnia were recorded and serum levels of calcium, phosphorus, alkaline phosphatase (Alk-ptase), iPTH, aluminum, and hemoglobin were measured in the study and control groups. At 12-week postoperatively, serum levels of calcium, phosphorus, Alk-ptase, iPTH, and aluminum were measured again and at 16-week postoperatively, the MMSE and the CDR test were administered again. In the control group, both MMSE and CDR test were administered again after the period or 16-week.


RESULTS
Serum calcium level was only significant difference (p = 0.002), whereas clinical symptoms, gender, etiologies of secondary hyperparathyroidism, duration of dialysis, educational level, age, and serum levels of phosphorus, Alk-ptase, iPTH, aluminum, and hemoglobin were not significantly different between the two groups. The educational level was the only factor affecting MMSE scores (p = 0.003). In the study group, at 12-week postoperatively, symptoms improved significantly, serum levels of calcium, phosphorus, Alk-ptase, iPTH, and aluminum decreased significantly, and at 16-week postoperatively, MMSE scores increased from 25 +/- 5 (mean +/- SD) to 26 +/- 5 (p < 0.001) and CDR scales decreased significantly (p < 0.001). Neither MMSE scores nor CDR scales of the control group changed significantly after the 16-week period.


CONCLUSIONS
Parathyroidectomy for symptomatic secondary hyperparathyroidism can improve cognition.
Chou
Fong-Fu
FF
Department of Surgery, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung Hsien, Taiwan.
Chen
Jin-Bor
JB
Hsieh
Kun-Chou
KC
Liou
Chia-Wei
CW
D000328:Adult; D000368:Aged; D003072:Cognition Disorders / Q000209:etiology / Q000601:surgery*; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000150:complications / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010280:Parathyroid Glands / Q000637:transplantation; D016105:Parathyroidectomy; D051437:Renal Insufficiency / Q000150:complications