Rare case of Marchiafava-Bignami disease due to thiamine deficiency and malnutrition

Marchiafava-Bignami disease (MBD) is a rare, toxic demyelinating disorder of the central nervous system associated with chronic alcoholism and malnutrition. The clinical presentation is varied and non-specific, including symptoms of acute dementia, impaired consciousness, dysarthria, hemiparesis, pyramidal tract signs, seizure activity, ataxia and signs of interhemispheric disconnection. The differential diagnosis of MBD may include Wernicke's encephalopathy, multiple sclerosis, encephalitis, infectious or paraneoplastic leucoencephalopathy, infarction, Alzheimer's disease, multi-infarct dementia and frontotemporal lobar degeneration (Pick) disease. The diagnosis of MBD is dependent on MRI findings of hyperintensity of the corpus callosum on T2 and fluid-attenuated inversion recovery T2 sequences, with or without extracallosal lesions. The use of MRI in diagnosis has allowed for early initiation of treatment with parenteral thiamine, and improved the prognosis of MBD from frequently fatal to a mortality of less than 8%. Administration of thiamine within 14 days of symptom onset has demonstrated statistically better outcomes over delayed treatment. We present a case report of MBD diagnosed in a 72-year-old woman who presented with ataxia and slurred speech, in an effort to highlight the importance of obtaining MRI in patients presenting with behavioural disturbance and neurological findings, as well as discuss the relationship between thiamine supplementation and demyelinating diseases in the central nervous system.