Cognitive impairment and intracranial calcification in chronic hypoparathyroidism

Intracranial calcification is associated with chronic hypoparathyroidism. The relationship between intracranial calcification, neurological abnormalities and cognitive deficits in this disorder is unknown. The purpose of this study was to determine whether chronic hypoparathyroidism is associated with cognitive impairment.

We studied 11 hypoparathyroid patients and compared them with a sex-, age-, and education-matched control group. The hypoparathyroidism was postsurgical in nine and idiopathic in two. All patients underwent nonenhanced head computed tomography, detailed neurological examinations, and a battery of cognitive tests. These tests were performed separately and individual examiners were blinded to the results of the other components of the study.

The mean age of the patients was 55 years; the duration of hypoparathyroidism was at least 9 years. Neuropsychological testing revealed cognitive impairment in 65% of hypoparathyroid subjects, and the presence of significant differences between the hypoparathyroid and control groups. Computed tomography showed intracranial calcification in 6 of 10 hypoparathyroid subjects tested, and neurological (motor) examination revealed 5 of 11 with abnormal findings. There were positive correlations between the presence of cognitive deficits and cerebral calcification (r = 0.59, P = 0.07), between abnormal motor findings and cerebral calcification (r = 0.77, P < 0.01) and between abnormal motor findings and the degree of cognitive deficit (r = 0.83, P < 0.01).

We conclude that cognitive and neurological deficits commonly occur in patients with chronic hypoparathyroidism and may be pathophysiologically related to the presence of intracranial calcification.