Regional cerebral blood flow in patients with primary hyperparathyroidism before and after successful parathyroidectomy.

Background: Single-photon emission computed tomography (SPECT) is used to study cerebral blood flow and cerebral metabolism in various neuropsychiatric disorders. Reduced regional cerebral blood flow has been demonstrated in patients with depression and chronic fatigue, symptoms that are common in primary hyperparathyroidism. The aim of this study was to reveal possible changes in regional cerebral blood flow in patients with primary hyperparathyroidism before and after operative treatment.

Methods: This was a prospective study of regional cerebral blood flow in 16 consecutive women of median age 72 (range 50-82) years using SPECT with (99m)Tc-labelled hexamethylpropylenamine-oxime. The measurements were performed before and 2, 4 and 12 months after parathyroidectomy. The Montgomery and Asberg depression rating scale (MADRS) depression score was used as a parallel clinical test.

Results: Reduced (pathological) regional cerebral blood flow was seen before operation in 14 patients, 13 with a solitary adenoma and one with double adenoma. After surgery, this improved to normal values in 13, but was further reduced in one. In two patients with preoperative normal regional cerebral blood flow, both of whom were asymptomatic and had diffuse hyperplasia, a slight reduction was demonstrated. Eight patients had a pathological preoperative MADRS score, which normalized in seven after surgical treatment.

Conclusion: The finding of reduced regional cerebral blood flow in patients with primary hyperparathyroidism followed by significant improvement after operation might influence the case for surgical treatment.