male with a lifelong learning disability and altered mental status
Three axial noncontrasted computed tomography (CT) images
are provided: the first 2 in brain
windows and the last in bone window. The CT images demonstrate dense, symmetric
calcifications involving the globus pallida, putamina, caudate nuclei, thalami,
subcortical white matter, and dentate nuclei. Mild generalized parenchymal-volume
loss is also present.
Fahr disease is a rare neurodegenerative disorder, which is
also known as idiopathic familial basal ganglia calcification, bilateral
striopallidodentate calcification, and familial cerebrovascular ferrocalcinosis.
The disease process is characterized by progressive deposition of calcium
within the walls of the capillaries and larger arteries and veins. Patients
usually present between the ages of 30 and 60 with cognitive impairment,
neuropsychiatric disturbances, and extrapyramidal movement disorders. There is
a bimodal distribution of clinical onset with younger patients preferentially
demonstrating psychiatric symptoms and older patients presenting with dementia
and extrapyramidal movement symptoms. There is no gender predilection, but many
cases are familial. The disease is characterized by very slow progression of
symptoms with no effective treatment options.
Fahr disease is most easily recognized by symmetric basal ganglia
calcifications, most commonly affecting the globus pallidus. Many cases also
involve the putamen, caudate, thalami, dentate nuclei, internal capsule, and
subcortical white matter. The calcifications are best detected by CT, although
susceptibility-weighted magnetic resonance imaging (MRI) sequences may be more
sensitive than CT. Occasionally, MRI may demonstrate white-matter
hyperintensity on T2-weighted images due to inflammation.
diagnosis of basal ganglia calcifications is broad and includes metabolic
causes, such as hypoparathyroidism, hyperparathyroidism, and birth hypoxia,
infectious causes such as TORCH infections, Tuberculosis, neurocysticercosis,
and AIDS, toxic causes such as radiation, chemotherapy, and carbon monoxide
poisoning, inherited disorders, such as MELAS and Cockayne syndrome, and also
may be idiopathic. Differentiation is usually by clinical symptoms and
- Provenzale J, Castillo M, et al. Fahr Disease. In: Diagnostic Imaging: Brain. 1st ed. Utah: Amirsys: 2004.I:lO:l8-9.
- Hegde AN,
Mohan S, Lath N, Lim CC. Differential diagnosis for bilateral abnormalities of the basal ganglia
and thalamus. Radiographics. 2011;31:5-30.
- Shenoy AM, Volpe D,
Ensrud ER. Fahr’s disease. Pract Neurol.
2009;9 :100-101. doi:10.1136/jnnp.2008.166157