Wilson’s disease is a rare genetic disorder characterized by deficiency of ceruloplasmin affecting copper metabolism, leading to excessive systemic copper deposition, particularly in liver and brain. The most frequent abnormalities reported in brain imaging are bilateral symmetrical T2-hyperintensity of the putamen and globus pallidus, followed by caudate nuclei, thalami, pons, midbrain, cerebellum and cerebral subcortical regions respectively [1-4]. The T2-weighted high signal changes represent oedema, gliosis, necrosis or spongiform cystic degeneration [2, 3]. Reversal of T2 signal changes can occur following copper chelating treatment [2]. Deposition of copper or iron ferritin can contribute to reduced signal on T2-weighted images. Kim et al reported that T1-weighted hyperintensity of the basal ganglia was the most common MR imaging finding in children which reflect hepatic involvement of the disease [2]. Diffusion restriction is generally seen in the early stages of the disease [1]. MR imaging can reveal a characteristic appearance of the mid brain called “face of the giant panda sign” due to high T2-signal in the tegmentum and normal signal of red nuclei [2, 3]. A similar sign is seen in the pons, albeit slightly smaller, aptly named the “face of the miniature panda” sign [3].
Bilateral symmetrical T2 hyperintensity of the basal ganglia in Wilson disease is most frequently associated with signal changes within the thalami, followed by the brain stem [1-4], however, our case demonstrated dominant symmetric involvement of the basal ganglia only. This type of presentation with bilateral symmetrical hyperintensity of basal ganglia most likely suggests: neurotoxicity due to carbon monoxide, methanol or cyanide poisoning, hypoglycaemia or hyperglycaemia, extrapontine myelinolysis due to rapid correction of hyponatraemia, Wilson disease and other liver diseases, lymphoma, ischaemia and other rare genetic causes like mitochondria diseases, Leigh disease [1-4]. The association of symmetric thalamic involvement widens the differentials with conditions like stroke, primary CNS lymphoma and infections. Addition of T2* GRE sequence can help in limiting the differentials with demonstration of hypointensities in basal ganglia which suggest deposition of iron or copper.
To conclude, the MRI features of bilateral T2 hyperintensity of basal ganglia as initial acute presentation of Wilson disease may not be typically diagnostic due to wide differentials. However, in the absence of toxic exposure or blood sugar disorder, no history of rapid electrolyte correction and presence of susceptibility changes at T2* GRE MR imaging, raises the likelihood of Wilson disease.