Marchiafava-Bignami disease is a rare, toxic, neurodegenerative disorder associated with alcohol use disorder and malnutrition and manifesting with neurological symptoms and findings on brain MRI. Cortical laminar necrosis and myelin destruction of the corpus callosum are the most common imaging findings. Patients can present with an acute onset of neurological symptoms or with a subacute to chronic decline. Signs and symptoms may include decline in mental function, memory loss, and unsteady gait. Advanced stage of decline includes delirium, disturbed gait, convulsions, and coma.

Onset is mostly in middle-aged and older men with a history of alcohol use disorder, but it can also occur in malnourished patients who lack a history of alcohol use. Therapies include thiamine supplementation and steroids, with the greatest negative outcome related to a delayed start of thiamine treatment.