Man with seizure.

Contributed from the case records of the  Indiana University Department of Radiology

Man with seizure.

Man with seizure.

• Wernicke encephalopathy
• Marchiafava-Bignami disease
• Central pontine myelinolysis
• Multiple sclerosis
• Diffuse sclerosis
• Postictal changes
• Acute toxic demyelination

Man with seizure.

Marchiafava-Bignami (MB) disease is an uncommon cause of acute or chronic neurological symptoms, usually in patients who abuse alcohol. Originally described in 1903 by Italian pathologists Ettore Marchiafava and Amico Bignami in three heavy drinkers of red wine, MB is on the spectrum of alcoholic neurologic disorders that includes Wernicke encephalopathy and Korsakoff syndrome. Now known to occur in nonalcoholics as well, MB is thought to be an idiosyncratic response to vitamin B deficiency resulting in inflammatory demyelination and subsequent necrosis of the corpus callosum. While involvement of all or part of the corpus callosum is required for diagnosis, other white matter tracts are often affected, with significant overlap with other alcohol-induced abnormalities. Presenting symptoms are nonspecific, most notably mental status changes, dysarthria, seizures, and hypertonia of either acute or chronic onset. Natural history is highly variable, ranging from complete recovery to coma and death. Supportive treatment is mainly aimed at correcting the underlying nutritional disturbance. Because of the overlap between MB and other neurological disorders, imaging work-up is key to diagnosis.

MB is part of a spectrum of central nervous system demyelinating disorders that includes Wernicke encephalopathy and Korsakoff syndrome. The defining feature of MB is inflammatory degeneration of the corpus callosum, evidenced by increased T2 signal on fluid-sensitive images. Restricted diffusion, demonstrated by increased signal on diffusion-weighted images with decreased signal on apparent diffusion coefficient images, is also typical. In later stages, the corpus callosum may atrophy. Involvement of other white matter tracts is common. For example, the patient in this case has mild diffuse cerebral and cerebellar atrophy. Note that the mammillary bodies are atrophied  a common finding in Wernicke encephalopathy. Also notable is the increased T2 signal in the superior colliculi and dentate nuclei bilaterally. Other findings of "pure" Wernicke encephalopathy are absent, including altered signal in the periaqueductal gray and thalamus.

• The defining imaging feature of Marchiafava-Bignami (MB) disease is altered signal of the corpus callosum, generally increased T2 and restricted diffusion.
• MB often presents with overlapping findings with other demyelinating syndromes, e.g. Wernicke encephalopathy. Again, what differentiates MB is involvement of the corpus callosum.
• Thought to be caused by vitamin B complex deficiency, MB is mainly seen in alcoholic or chronically malnourished patients.

References:

1. Arbelaez A et al., Acute Marchiafava-Bignami disease: MR findings in two patients, AJNR Am J Neuroradiol (2006) 24:1955–1957.
2. Goswami P et al., MRI findings in Marchiafava - Bignami disease with central pontine myelinolysis: A case report, Indian Journal of Neuroradiology (2006) 16(4):779-781.
3. Statdx, Alcoholic encephalopathy, www.statdx.com, retrieved 7/1/2011.

Man with seizure.