| Abstract: | Prospective neurologic and psychologic studies were thus undertaken in 19 patients who were to undergo major neck operations either for parathyroidectomy (seven for primary hyperparathyroidism and six for secondary hyperparathyroidism) or other reasons (six control subjects). A complete physical and neurologic examination, laboratory tests (calcium, PTH), roentgenograms, a standard electroencephalogram and psychologic testing were carried out in patients before and three and a half months after neck operation.The preoperative electroencephalograms were abnormal in groups with both primary and secondary hyperparathyroidism. For the patients with primary hyperparathyroidism, the preoperative electroencephalogram revealed a percentage electroencephalographic power below 5 Hz (± SE) of 4.2 ± 2.2 per cent (normal = 2.4 ± 1.0 per cent), and the percentage of electroencephalographic frequencies below 7 Hz was 14.7 ± 3.2 per cent (normal = 6.0 ± 1.6 per cent). Postoperatively, however, there were significant (p < 0.01) decrements in these measurements to normal values. The percentage electroencephalographic power below 5 Hz was 1.5 ± 0.6 per cent, whereas the percentage of electroencephalographic frequencies below 7 Hz was 5.2 ± 1.1 per cent. In patients with secondary hyperparathyroidism, both the percentage electroencephalographic power below 5 Hz (9.7 ± 2.5 per cent, p < 0.01) and the percentage electroencephalographic frequencies below 7 Hz (22.2 ± 4.2 per cent, p < 0.01), were significantly higher than normal values. There were significant decrements in all the abnormal electroencephalographic values postoperatively. The percentage electroencephalographic power below 5 Hz decreased to 3.4 ± 2.4 per cent, and the percentage electroencephalographic frequencies below 7 Hz decreased to 17.4 ± 3.1 per cent. Electroencephalograms in control patients did not change.Patients with primary hyperparathyroidism showed no significant postoperative improvement in any of the psychologic parameters tested. By contrast, patients with secondary hyperparathyroidism showed improvement in several areas of testing after undergoing surgery when compared to control subjects.The brain calcium in four other patients with secondary hyperparathyroidism who died of miscellaneous causes was 38.3 ± 5.7 meq/kg dry wt, versus the normal value of 25.2 ± 0.7 meq/kg dry wt (p < 0.03).These data show that in patients with either primary or secondary hyperparathyroidism, the electroencephalogram is abnormal and shows significant improvement following parathyroidectomy. There is also improvement in several tests of intellectual function in patients with secondary hyperparathyroidism. Brain calcium content was significantly higher than normal in patients with secondary hyperparathyroidism. |
