DIAGNOSIS
The clinical presentation and MRI findings are suggestive of Marchiafava-Bignami disease. It is a rare condition, frequently associated with alcoholism. Brain MRI may show callosal, but also extra callosal white matter, and cortical lesions.1,2 Our case is unique because there was oedema which subsequently resolved on repeat MRI. The course of the disease may be acute, sub-acute, or chronic, and is marked by dementia, spasticity, dysarthria, and inability to walk. Patients may lapse into a coma and die, survive for many years in a demented condition, or occasionally recover. An interhemispheric disconnection syndrome has been reported in survivors.3
What else can smudge the ‘tough body’ corpus callosum? Infarction isolated to the corpus callosum is relatively rare given its robust collateral blood supply. When infarctions occur, the splenium is most often affected, followed by the body and genu. Susac syndrome is an arteriopathy which causes small multifocal snowball-like lesions predominantly involving the central parts of the corpus callosum. Other features of Susac syndrome are encephalopathy, branch retinal artery occlusion and hearing loss. With its predominance of myelinated fibres, the corpus callosum is also affected by demyelinating diseases, such as multiple sclerosis and acute disseminated encephalomyelitis. Callosal lesions in multiple sclerosis tend to be small and involve the inferior aspect. Acute disseminated encephalomyelitis causes larger enhancing lesions that often cross the midline and may reach the upper and lower margins of the corpus callosum.4
DISCLOSURES
All authors declare no conflict of interest. No funding or financial support was received.
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