Perioperative changes in cortical excitability, mood, and quality of life in patients with primary hyperparathyroidism: a pilot study using transcranial magnetic stimulation

Objective: Serum calcium (Ca2+) and parathyroid hormone (PTH), amongst others, modify cortical excitability. Alterations in cortical excitability were shown in patients with epilepsy as well as hyper- or hypoparathyroidism. In patients with primary hyperparathyroidism (pHPT), preoperative elevated serum calcium and parathyroidectomy (PTx) may affect mood and quality of life. We hypothesized that perioperative changes in Ca2+ and PTH in pHPT will affect cortical excitability and improve subjective health. Design and methods: Transcranial magnetic stimulation (TMS) was performed before and after surgery in 15 pHPT patients. We measured resting motor threshold, cortical silent period (CSP), short intracortical inhibition, and intracortical facilitation. Health questionnaires were administered before, 1 day and 6 months after PTx, along with the disease-specific Pasieka's parathyroid assessment of symptoms (PAS), which was, to our knowledge, its first use in German. Results: Surgery was successful in all patients. TMS-measurements remained unchanged when analyzing all patients in this pilot study. Postoperatively, depression declined (P=0.05) and quality of life improved significantly (P=0.001) in the SF-36-subscales: vitality, social functioning, mental health and subjective health transition (post-hoc analysis). The PAS proved early relief of disease-specific symptoms (P<0.001). Conclusions: We found unchanged cortical excitability comparing pre- and post-PTx in this pilot study. Mood and quality of life improved postoperatively. The German PAS is valuable in detecting disease-specific changes early after PTx.