Marchiafava-Bignami disease with partial corpus callosum involvement: A case report

A 31-year-old male presented at our emergency department with incomprehensible speech and decreased sensorium. No focal neurologic deficits were found. Two days prior, he had an alcoholic drinking spree. He presented with similar symptoms after alcohol intoxication three years prior but was discharged well after a day of hospital admission.

A non-enhanced cranial CT was initially done, revealing hypodensities in the splenium of the corpus callosum (Figure 1).

A contrast-enhanced MRI of the cranium was subsequently performed. The splenium of the corpus callosum was edematous, with focal hypointensity on T1-weighted imaging (T1WI) and hyperintensity on T2-weighted imaging (T2WI) and fluid-attenuation inversion recovery (FLAIR) (Figure 2). The abnormal signals were located centrally within the expanded splenium, sparing its undersurface, with corresponding restricted diffusion on diffusion-weighted imaging (DWI) and decreased apparent diffusion coefficient (ADC) value. No magnetic susceptibility artefacts or enhancement was identified.

Additional T1-/FLAIR-hyperintense signals were seen in the cortex of the left temporal lobe (Figure 3). Corresponding enhancement was found on post-gadolinium scan, but no restricted diffusion or magnetic susceptibility artefacts were noted.

Marchiafava-Bignami disease (MBD) is an uncommon sequela of alcohol intoxication primarily resulting in corpus callosum demyelination and necrosis. A minority of cases are non-alcoholics but with prior history of malnourishment or metabolic disorder [1-6]. It is seen predominantly in men ranging from 40 – 60 years old [3,5].

The pathophysiology of the disease remains unclear. Widely accepted theories include the direct neurotoxic effect of alcohol on white matter and vitamin B1 (thiamine) deficiency [2,5,6]. Ethanol can incite oxidative stress and vitamin B1 deficiency, causing damage to the corpus callosum. Vitamin B1 deficiency, by itself, can cause imbalances in neurotransmitter activity and impair normal myelin and glutathione synthesis. Specific involvement of the corpus callosum was theorized to be due to its high myelin content [2,5].

MRI is the imaging study of choice for the diagnosis of MBD [5]. Symmetric lesions in the corpus callosum are the classic finding. In the acute phase, these appear hypointense in T1-weighted imaging and hyperintense in T2-weighted, FLAIR, and DWI sequences, indicative of cytotoxic oedema. These are typically distributed in the central regions of the corpus callosum, with sparing of its ventral and dorsal layers, resulting in the so-called sandwich sign. Post-contrast enhancement is variable. With timely management, eventual resolution of these findings may occur. However, in the absence of treatment or poor treatment response, atrophy and cystic degeneration of the corpus callosum may ensue in the chronic stage [1-7].

The degree of corpus callosum involvement correlates with patients’ clinical features and prognosis. Symmetric lesions involving the genu, body, and splenium are the most common and typical findings of MBD. However, cases with focal involvement, as in our patient, have also been reported [3,4,6,7]. Two clinicoradiologic subtypes of MBD are recognized. Heinrich’s Type A disease presents with diffuse involvement of the corpus callosum and has a more severe clinical course with worse outcome. On the other hand, Type B disease shows focal corpus callosum involvement and has a milder clinical course with a better prognosis [3-5,8,9].

Although infrequent, extracallosal lesions in the white matter, basal ganglia, and cortex have been reported and are associated with poorer clinical outcomes [1-3,6,7]. Their presence has also been associated with more extensive lesions in the corpus callosum [3].

In our case of MBD, we demonstrated partial involvement of the corpus callosum. Although unilateral cortical abnormalities were also seen in the left temporal lobe, their signal characteristics differed from those in the corpus callosum lesion, suggesting that this may be a different or unrelated lesion.