Bilateral symmetrical dense calcifications in the dentate nuclei, basal ganglia, thalami, and subcortical white matter are pathognomonic of Fahr syndrome.

Primary familial brain calcification (Fahr disease) typically presents between 40 and 60 years of age and has a progressive course.

Calcification in a similar distribution but secondary to another disease process is referred to as Fahr syndrome. As well as thyroid disease, many other possible underlying causes have been described: see Fahr syndrome.