Cytomegalovirus (CMV): The most common congenital infection. It classically causes periventricular calcifications due to damage to the germinal matrix. Associated with microcephaly, chorioretinitis, and sensorineural hearing loss.
Toxoplasmosis: Presents with the classic triad of chorioretinitis, hydrocephalus, and diffuse, scattered parenchymal calcifications. The calcified nodules are randomly distributed throughout the brain.
Vascular
Sturge-Weber Syndrome: A neurocutaneous disorder characterized by a facial port-wine stain (nevus flammeus) and leptomeningeal angioma. This leads to gyriform, “tram-track” cortical calcifications, which are usually unilateral and most common in the parietal and occipital lobes. Neurological symptoms include seizures and intellectual disability.
Neoplastic
Craniopharyngioma: The most common childhood supratentorial tumor, arising from Rathke’s pouch remnants. Typically presents as a suprasellar, cystic, and calcified mass. Calcification is present in about 90% of pediatric cases. It often causes bitemporal hemianopsia and endocrine dysfunction.
Oligodendroglioma: A slow-growing brain tumor in adults, often presenting with seizures. Calcifications are common, and histology classically shows “fried-egg” cells.
Meningioma: A benign tumor arising from the dura. Histology often reveals psammoma bodies, which are laminated calcifications.
Infectious (Acquired)
Neurocysticercosis: Caused by the larvae of Taenia solium, it is a major cause of adult-onset seizures worldwide. Imaging shows multiple small, calcified cysts, sometimes described as a “starry sky” appearance.
Tuberculosis: CNS infection can lead to tuberculomas, which may calcify, often located at the base of the brain.
Metabolic / Endocrine
Hypoparathyroidism / Pseudohypoparathyroidism: These conditions are among the most common causes of pathological basal ganglia calcification (Fahr’s syndrome). They cause bilateral and symmetric calcifications in the basal ganglia due to disturbances in calcium and phosphate metabolism. Patients may present with movement disorders or cognitive changes.