Basal ganglia calcification on computer tomographic scan

Computerised tomography of the brain was used to demonstrate basal ganglia calcification which may be of an insufficient degree to be seen on skull X-ray.
Cases referred for CT scan from hospitals in Singapore for various reasons over a period of 12 months were studied for basal ganglia calcification. There was a startlingly high incidence of 1.5%, as 47 cases (all except 2 were Chinese) showed such calcification. In 42 cases there was no evidence of basal ganglia calcification on skull X-ray. 16 cases showed neurological affection, fits being the commonest manifestation.
An unexpected finding was that no case had abnormality of calcium metabolism or evidence of hypoparathyroidism or pseudohypopara-thyroidism.
The CT scan is very sensitive in demonstrating minimal basal ganglia calcification and our impression is that such calcification is common.