Idiopathic brain calcification in a patient with hereditary hemochromatosis

Detection of brain-MRI T2/T2* gradient echo images (T2*GRE)-hypointensity can be compatible with iron accumulation and leads to a differential diagnosis work-up including neurodegeneration with brain iron accumulation (NBIA) and Wilson Disease. Idiopathic or secondary brain calcification can be also associated with neurological involvement and brain-MRI T2/T2*GRE-hypointensity. Hereditary hemochromatosis (HH), characterized by systemic iron loading, usually does not involve the CNS, and only sporadic cases of neurological abnormalities or brain-MRI T2/T2*GRE-hypointensity have been reported.

A 59-year-old man came to our observation after a diagnosis of HH carried out in another hospital 2 years before. First-level genetic test had revealed a homozygous HFE p.Cys282Tyr (C282Y) mutation compatible with the diagnosis of HFE-related HH, thus phlebotomy treatment was started. The patient had a history of metabolic syndrome, type-2 diabetes, autoimmune thyroiditis and severe chondrocalcinosis. Brain-MRI showed the presence of bilateral T2*GRE hypointensities within globus pallidus, substantia nigra, dentate nucleus and left pulvinar that were considered expression of cerebral siderosis. No neurological symptoms or family history of neurological disease were reported. Neurological examination revealed only mild right-sided hypokinetic-rigid syndrome. Vitamin D-PTH axis, measurements of serum ceruloplasmin and copper, and urinary copper were within the normal range. A brain computed tomography (CT) was performed to better characterize the suspected and unexplained brain iron accumulation. On the CT images, the hypointense regions in the brain MRI were hyperdense. DNA sequence analysis of genes associated with primary familial brain calcification and NBIA was negative.

This report highlights the importance of brain CT-scan in ambiguous cases of suspected cerebral siderosis, and suggests that HH patients with a severe phenotype, and likely associated with chondrocalcinosis, may display also brain calcifications. Further studies are needed to confirm this hypothesis. So far, we can speculate that iron and calcium homeostasis could be reciprocally connected within the basal ganglia.