Cognitive deficits in primary hyperparathyroidism - what we know and what we do not know: A narrative review

Classic symptoms of primary hyperparathyroidism (PHPT) are seen in approximately 20% of patients. While features such as kidney stones and skeletal disease are often highlighted as directly related to the disease, others can be even more prevalent. For example, cognitive dysfunction and reduced quality of life are common complaints in many patients, even among those who are classified as being asymptomatic. The pathophysiology of PHPT involves the impact of excess parathyroid hormone (PTH) on calcium metabolism. Referencing putative neurocognitive issues, many animal studies have illustrated the potential roles of PTH and PTH receptors in the brain. Functional imaging and pre-and post-parathyroidectomy studies have suggested a link between the neuronal impact of elevated PTH levels on specific functional aspects of the central nervous system, such as cognition. Confounding a direct role for PTH are hypercalcemia and vitamin D deficiency, both of which could conceivably alter CNS function in PHPT. The lack of strong evidence that parathyroidectomy improves cognition in patients with PHPT raises the question as to whether parathyroid surgery should be recommended on this basis alone. This narrative review summarizes the available literature on neurocognitive function in PHPT.

Influence of Parathyroidectomy on Sleep Quality in Primary Hyperparathyroidism

We investigated the impact of parathyroidectomy on sleep quality in patients with primary hyperparathyroidism (pHPT). Thirty consecutive patients with pHPT were enrolled in the study within 1 year. pHPT was diagnosed by typical symptoms accompanied by an elevated level of parathormone. The Pittsburgh Sleep Quality Index (PSQI) was used for the evaluation of sleep 1 day before and 6 months after parathyroidectomy. The mean total PSQI score was elevated to 6.8 ± 0.6 points before surgery, which was in the pathological cut-off of greater than ≥5, indicating impaired sleep quality. After parathyroidectomy, the total score declined insignificantly, amounting to 5.6 ± 0.4 (p > 0.05). Nevertheless, the number of patients with a score of ≥5 before surgery decreased from 21 (70%) to 16 (53%) after surgery. There also was a significant improvement in sleep latency (p = 0.05) and sleep efficiency (p = 0.02) domains of PSQI. We conclude that 70% of patients with untreated pHPT suffered from sleep disorders that improved after parathyroidectomy. The clinical consequence is that patients with pHPT should be questioned about having sleep disorders, which might influence the decision-making concerning parathyroidectomy. With the relation reversed, patients without pHPT but suffering from sleep disturbance should be tested for pHPT.

(18)F-Fluorocholine PET-CT enables minimal invasive parathyroidectomy in patients with negative sestamibi SPECT-CT and ultrasound: A case report

INTRODUCTION

Primary hyperparathyroidism is a common endocrine disorder for which the primary treatment is surgery. For minimal invasive parathyroidectomy adequate pre-operative imaging is essential. Conventional imaging is often inconclusive. There are reports that (18)F-fluorocholine PET-CT might be a superior imaging modality, however evidence is still very scarce. This is the first report of a case with negative ultrasound and sestamibi SPECT-CT imaging that underwent successful minimal invasive surgery because of (18)F-fluorocholine PET-CT.

PRESENTATION OF CASE

A 57 year-old man presented to us with complaints of fatigue. Laboratory results showed a biochemical primary hyperparathyroidism and an additional DEXA-scan revealed osteopenia of the lumbar spine. Conventional imaging consisting of neck ultrasound and Tc-99m-sestamibi SPECT-CT was however unable to localize the pathological gland. Subsequent (18)F-fluorocholine PET-CT did clearly localize an adenoma dorsally of the left thyroid lobe which was removed at that exact location using minimal invasive parathyroidectomy. Histological examination confirmed the diagnosis adenoma and calcium levels remained normal at follow-up.

DISCUSSION

There is clinical need for a superior imaging modality to detect pathological parathyroid glands to enable minimal invasive surgery. (18)F-Fluorocholine is widely available.

CONCLUSION

(18)F-Fluorocholine PET-CT is a promising new imaging modality for localizing parathyroid adenomas and enabling minimal invasive parathyroidectomy when conventional imaging fails to do. Clinicians should consider its use as a second line modality for optimal patient care.