Marchiafava-Bignami disease (MBD) is a rare condition characterized by demyelination of the corpus callosum. It is seen most often in patients with chronic alcoholism. (See Etiology and Pathophysiology.)
In 1903, Italian pathologists Marchiafava and Bignami described 3 alcoholic men who died after having seizures and coma. In each patient, the middle two thirds of the corpus callosum was found to be severely necrotic. Through the years, the medical literature accumulated hundreds of cases of MBD.[1] Most of these cases were found in alcoholic men.
With the advent of computed tomography (CT) scanning and magnetic resonance imaging (MRI), more cases of MBD have been recognized than before. Analyses of such cases have revealed several patterns, including scattered lesions or cysts observed at intervals from the front to the back of the callosum. Nearby areas (eg, anterior commissure, posterior commissure, brachium pontis, other white-matter tracts) and the centrum semiovale are frequently involved. (See Workup.)
In 2007, Celik et al reported a case of a nonalcoholic patient with acute MBD that was associated with a gynecologic malignancy. The authors raised the question of a possible paraneoplastic MBD.[2] That same year, Rusche-Skolarus et al described a case of MBD in a postoperative, nonalcoholic female who presented with an encephalopathy. (See Etiology and Pathophysiology.)[3]
In 2004, Heinrich et al described 2 clinical subtypes of MBD as follows, based on a review of 50 radiologic cases diagnosed in vivo[4] :
Alcoholism remains the greatest risk factor for MBD, although rare cases have occurred in individuals who did not drink alcohol. Nutritional factors have been suspected in MBD, but no specific nutrient has been identified. Electrolyte disturbances (as in central pontine myelinolysis) may be important.
Although the callosal lesions are the hallmark of the disease, for years some cases of MBD were known to be associated with cortical damage in addition to damage to the white matter tracts of the corpus callosum. Generally, the cortical damage was in the lateral frontal and the temporal lobes, mainly in the third (although sometimes also in the fourth) cortical layer. In these areas, the neurons degenerated and were replaced by glial cells. In 1939, Morel described this as cortical laminar sclerosis (now known as Morel cortical laminar sclerosis).[5]
Although Morel did not report an association between cortical laminar sclerosis and MBD, many subsequent authors did, including Jequier and Wildi in 1956[6] and Delay et al in 1959.[7, 8] Indeed, Ropper et al stated in 2005,[9] in Adams and Victor's Principles of Neurology, that Jequier and Adams (in an otherwise unpublished review) reexamined Morel's slides and found evidence of MBD in all of those cases. Thus, the prevailing view has generally been that Morel cortical laminar sclerosis is secondary to MBD.
Nevertheless, in 1978, Naeije et al reported a case of Morel cortical laminar sclerosis in an alcoholic woman who did not have MBD.[10] In addition, Okeda et al reported 3 cases of cortical laminar sclerosis in 1986 in patients who had various combinations of pontine and extrapontine myelinolysis but who did not have MBD.[11] One of these patients had alcoholic cirrhosis and 2 had malignancies.
Single-photon emission computed tomography (SPECT) scanning has yielded interesting pathophysiologic data related to MBD. In a published case reported by Ferracci et al in 1999, SPECT scanning showed a bilateral reduction in cerebral blood flow. The patient had left hemispatial neglect in addition to the expected left-handed apraxia and agraphia.[12]
In 2003, Gambini et al used magnetic resonance spectroscopy to suggest that an inflammatory reaction accompanies demyelination and necrosis.[13] In 2005, Johkura et al reported 2 cases in which lateral and frontal cortical lesions, in addition to corpus callosal lesions, were seen on fluid-attenuated inversion recovery (FLAIR) imaging.[14]
In 2006, Nardone et al reported on a partially recovered patient with MBD who demonstrated impairment of transcallosal inhibition. When performed properly, transcranial magnetic stimulation of the motor cortex elicits excitatory responses in contralateral hand muscles and suppresses tonic voluntary activity in ipsilateral muscles. The corpus callosum conveys the inhibitory signal. This inhibition was reduced this patient.[15]
Although this disease occurs in both sexes, most cases are found in men. Most cases of MBD occur in persons older than 45 years.
Alcohol abuse is such a common problem that underdiagnosis of MBD seems likely (although now, with the availability MRI, fewer cases are going undiagnosed). In addition, many cases of MBD may be diagnosed but not reported, and autopsies are largely not performed. Hence, the disease may be more common than thought, and the overall outcome may be better than previously believed.
MBD is a very rare condition. In 2001, Helenius et al wrote that they had found approximately 250 cases in published reports, although they also suggested that many cases had gone undiagnosed.[16]
The authors of this article have estimated that approximately 300 cases of MBD turned up in published reports between 1966 and November 2008. Another 40 or 50 cases have been mentioned in textbooks that are too old to have been included in the author's PubMed search.
International cases of MBD are similar to US cases, but 1 additional detail deserves mention. Some of the old literature on MBD suggested that this condition was more common in Italians. This was solely an artifact of the initial cases having been found in Italy and the fact that, at first, Italian physicians were apparently the only investigators interested in finding such cases. MBD has since been found in persons from all over the world.
It is now firmly believed that no national, geographic, ethnic, or racial predilection is known for MBD. However, with such few reports, the numbers of cases reported from each country could not be expected to be exactly in proportion to the population size of each country. In 2006, Staszewski et al described the first case in Poland, which was detected by MRI.[17]
In the era before CT scanning, MBD was found almost exclusively at autopsy. Patients with the condition usually died from the effects of alcoholism and typically had severe neuropsychological deficits before death. Helenius et al reported in 2004 that among approximately 250 known patients with MBD, 200 died, 30 remained severely demented or bedridden, and only 20 had a favorable outcome. If the underlying cause of MBD is alcoholism, the prognosis is poor unless the patient adheres to an alcohol treatment program.
However, modern CT scanning and MRI have allowed the detection of mild cases of the disease, and some patients have recovered with minimal deficits. Moreover, data suggest an improved overall prognosis for MBD.
The prognosis for MBD is correlated with the subtype, as follows:
In a 2004 review of acute and chronic cases of MBD, Heinrich et al separated most cases into 2 groups. Group A included the worst cases, in which patients presented with coma or other severe impairment of consciousness. On MRI scans, their lesions typically involved most or all of the corpus callosum. For example, in the acute phase, the entire corpus callosum was commonly hyperintense on T2-weighted MRI scans. As the lesions evolved, considerable necrosis occurred, and cystic areas of necrosis were present in most or many regions of the corpus callosum. The death rate for patients with such presentations was high (21%), and those who lived frequently had severe deficits.
In group B, patients had little or no impairment of consciousness. Their deficits were subtle and included various cognitive difficulties and signs of impaired interhemispheric information transfer, gait disturbances, dysarthria, limb hypotonia, and rare seizures or upper motor neuron signs. Initial hyperintense lesions on T2-weighted MRI scans were limited to a few areas of the corpus callosum. Some cystic necrotic areas developed over time, but they were fewer and smaller than those in type A. No deaths occurred in this group, and patients frequently had good recoveries.
The authors did not attempt to correlate the severity of the cases with the presumed causes. Patients with the most severe alcoholism might have been in group A, but this is speculation. In both groups, the amount of early callosal edema in the acute phase often markedly exceeded the areas of ultimate cystic necrosis.
In 2006, Menegon et al reported 6 patients with MBD in whom (1) the entire corpus callosum appeared to be affected by a reduced apparent diffusion coefficient, as seen on diffusion-weighted imaging studies, and (2) lateral and frontal cortical lesions were also detected by diffusion-weighted imaging. Menegon et al suggested, on the basis of the outcomes of their patients, that such a combination of findings was a harbinger of poor outcome for cognitive recovery and for survival.[18]
However, as pointed out by Khaw et al in 2006,[19] the older literature, such as that by Brion, from 1977,[20] does not support a correlation between laminar sclerosis and bad outcome. In addition, studies such as that by Hlaihel et al from 2006[21] do not support a correlation between reduced apparent diffusion coefficient and poor prognosis or even with irreversibility of the lesion.
Finally, they noted that cortical MRI findings have not been definitively correlated with the specific pathology of Morel cortical laminar sclerosis. However, if indeed they represent laminar sclerosis, the fact that this is present in the acute or subacute stages of MBD may force a reevaluation of the thought that laminar sclerosis is a secondary consequence of the MBD.
Most patients diagnosed with Marchiafava-Bignami disease (MBD) have a history of alcoholism and poor nutrition. The tempo of onset and the range of clinical symptoms vary. Some patients present to the hospital with sudden onset of stupor or coma, and some present with seizures. Other patients have acute, subacute, or chronic onset of dementia and/or gait problems. Spasticity often complicates the gait disorder. Psychiatric disturbances, incontinence, hemiparesis, aphasia, and apraxia have been described.
Although the physical findings in MBD are typically nonspecific, a good physical examination may offer clues to the diagnosis. However, patients with severe alcoholism who have this syndrome frequently have other problems, such as subdural hemorrhage, Wernicke-Korsakoff syndrome, and alcoholic liver disease. Therefore, the diagnosis is not often clear.
Patients later found to have MBD frequently present to an emergency department in a disheveled condition suggestive of chronic problems with alcohol.
Patients can be lethargic, stuporous, or even unconscious (coma or seizures). If a patient is sufficiently alert for extensive neuropsychological testing, testing for ideomotor apraxia (ie, inability to perform motor activities that is not explainable by overt motor or sensory loss) may be revealing.[22]
Apraxia of the left (or nondominant) hand suggests interhemispheric disconnection (ie, impaired transfer of information from the left hemisphere to the right hemisphere). Damage to the fibers of the corpus callosum is the cause.
Inability to retain new information (ie, Korsakoff syndrome, the chronic phase of Wernicke-Korsakoff syndrome) and delirium tremens should suggest alcoholism and prompt the examiner to consider other alcohol-related problems, such as MBD. Dementia and aphasia have been noted in some patients with this disease.
Nystagmus or disconjugate eye movements, possibly together with confusion and/or ataxia, may indicate the acute/subacute encephalopathic Wernicke phase of the Wernicke-Korsakoff syndrome, which should prompt the examiner to consider MBD.
Tremors, weakness, spasticity, and gait abnormalities, although nonspecific, have been seen in patients with MBD.
Delirium tremens is another alcohol-induced problem that patients with MBD may have. Currently, no evidence suggests that the presence of one is either positively or negatively correlated with the presence of the other.
Sensory loss may suggest an alcoholic neuropathy.
Wide-based gait and truncal ataxia suggest alcoholism.
Alcoholic neuropathy can cause a loss of deep tendon reflexes and, therefore, prompt the consideration of MBD in some patients. The presence or absence of Babinski signs is not known to be specifically related to MBD.
Because many patients with Marchiafava-Bignami disease (MBD) present with stupor or coma and seizures, the initial laboratory investigations should include measurements of serum electrolyte and glucose levels, a complete blood count (CBC), and toxicology screening. Glucose and intravenous (IV) thiamine are frequently given in the emergency department immediately after blood is drawn.
A spinal tap often is needed and usually is performed after findings on a brain CT scan have excluded an intracranial mass or hemorrhage.
Electroencephalography is frequently performed to evaluate seizures. No electroencephalographic findings are specific for or characteristic of MBD.[23]
Findings on the initial CT scan may confirm the diagnosis of MBD. If callosal damage is mild, however, it may go unnoticed until the radiologist has carefully reviewed the CT scan. In some cases, the lesions may not be visible on the scan.
MRI is currently the most sensitive diagnostic tool for MBD.[24, 25] Fast spin-echo, T2-weighted MRI scans show hyperintensity of the lesions due to edema and myelin damage.
Hypointensity on T1-weighted images is mainly related to a total loss of myelin, with replacement of the region by a cyst. Neurons can also be lost, in a situation similar to that of multiple sclerosis. As reported by Sair et al, diffusion tensor imaging and the associated technique of fiber tracking can further increase the sensitivity of MRI.[26]
Acute or subacute lesions are characterized by edema and early myelin damage more than other changes. As lesions become chronic, cystic lesions are likely to develop. Cystic lesions are generally hyperintense around the rim on T2-weighted MRI scans and hypointense in the actual cavity on T1-weighted images. (See the image below.)
View Image | T2-weighted axial image in a patient with Marchiafava-Bignami disease showing a high-signal lesion in the corpus callosum. |
Fluid-attenuated inversion recovery (FLAIR) images may be even more sensitive than those described above. Hyperintense rims and hypointense cores on FLAIR images probably represent damage to the myelin at the rim, with a central necrotic area. Uniformly hyperintense lesions may contain a mixture of demyelination and edema. In acute lesions, the area of edema seen is frequently larger than the area of permanent damage.
Pathology may also be seen on diffusion-weighted imaging. Unlike in stroke, however, in MBD, according to a report by Hlaihel et al, it is not uncommon for areas of restricted diffusion to resolve completely without apparent permanent damage.[21, 27]
Degeneration of the corpus callosum is a cardinal feature of MBD. The middle portion (middle lamina) of the myelinated fiber tracts of the corpus callosum degenerates. The degeneration is frequently, but not always, uniform. In some cases, the anterior portion is preferentially involved, with the most severe degeneration in the center of the lesion.
The anterior and posterior commissures, the centrum semiovale, the brachium pontis, and the other white-matter tracts (eg, the long association fibers and the middle cerebral peduncles) may also be affected. However, the internal capsule and corona radiata, as well as the shorter arcuate subgyral association fibers, are typically spared. If the splenium of the corpus callosum is affected, the greatest degeneration most commonly occurs in the lateral portions of the middle segment.
Histopathologic studies reveal abundant macrophages in the areas of lesions. Otherwise, little inflammatory reaction is noted. Axons are demyelinated in the involved areas, but the axon cylinders are relatively spared, particularly in the peripheral portions of the lesions. Deep in the lesion, cavitation, or cyst formation may be seen and corresponds to complete necrosis of all neural and glial elements.
Patients with MBD do not usually have midline lesions, which are typical in patients with Wernicke-Korsakoff syndrome (of the medial thalamus or mamillary bodies).
Finally, as previously mentioned, cortical lesions are sometimes found on postmortem neuropathologic studies. In such cases, neuronal degeneration of the third and fourth layers of the frontal and temporal cortices has been found, with replacement of the neuron by gliosis (ie, Morel cortical laminar sclerosis).
Controversy exists as to whether cortical MRI findings in MBD actually correlate with such pathologic findings and whether they may have implications for prognosis. Whether the cortical findings are secondary to the callosal damage, whether both are caused by a similar process, or whether they are coincidental findings that may also occur separately, particularly in severe alcoholism, malnutrition, and/or other severe impairments, remains unclear.
No specific, proven treatment is available for Marchiafava-Bignami disease (MBD). Various treatments similar to those commonly administered for Wernicke-Korsakoff syndrome or for alcoholism in general have been given to patients with MBD. Some patients have improved and some have not. The most common treatments are thiamine, folate, and other B vitamins (especially vitamin B-12). Folate is commonly given with B-12.
Because thiamine deficiency is associated with malnutrition and prolonged vomiting in alcoholics, MBD patients with these symptoms may benefit from parenteral thiamine administered within 2 weeks of symptom onset.[28]
With regard to more unusual treatments, a case report by Staszewski et al described amantadine given together with thiamine, vitamin B-12, and folate; the patient improved.[17] In another case, reported by Kikkawa et al, administration of high-dose corticosteroids was said to precede clinical improvement. In patients who improved, the CT and MRI scan findings also improved, at least somewhat.[29]
Patients are usually admitted because they present with stupor, coma, and, frequently, seizures.
Patients who survive should receive rehabilitation and, if appropriate, alcohol and nutritional counseling.
Depending on the specific presentation and course of MBD, the patient may require consultation with the following specialists:
Thiamine is administered for Wernicke-Korsakoff syndrome, but no significant evidence suggests that thiamine is a specific treatment for Marchifava-Bignami disease (MBD). Vitamin B-12, folate, and other B vitamins (and sometimes multivitamins) are also frequently given to sick, alcoholic patients admitted to the hospital; the authors deem administering the same protocol of vitamin therapy that would be given to patients with possible Wernicke-Korsakoff syndrome justified.
The fact that the brain pathology can now be observed repeatedly via serial MRI scans raises the question of whether to try other treatments mentioned in the literature and then monitor the appearance of the brain. A course of high-dose IV corticosteroids (eg, 250mg methylprednisolone q6h) could be tried if the attending physician believes that the possible benefits outweigh the risks.
Likewise, a standard dose of amantadine (100mg bid) could be considered if the patient can safely take it orally or through a tube. However, remember that no method exists to calculate a risk-to-reward ratio from isolated case reports, and the improvement seen in the small number of individual patients who received such treatments might have occurred anyway with the passage of time.
Clinical Context: Thiamine is a water-soluble vitamin that combines with adenosine triphosphate to form the coenzyme thiamine pyrophosphate, which is necessary for carbohydrate metabolism. The B vitamins are readily absorbed from the gastrointestinal (GI) tract (except in cases of malabsorption syndromes). Alcohol inhibits the absorption of thiamine, which occurs primarily in the duodenum.
Improvement has been seen in the small number of individual patients who received treatments that included at least 1 agent in this drug category.
Clinical Context: Methylprednisolone may decrease inflammation by reversing increased capillary permeability and suppressing polymorphonuclear (PMN) leukocyte activity.
Improvement has been seen in the small number of individual patients who received treatments that included at least 1 agent in this drug category.
Clinical Context: Amantadine inhibits N-methyl-D-aspartic acid (NMDA) receptor-mediated stimulation of acetylcholine release in rat striatum. Amantadine may enhance dopamine release, inhibit dopamine reuptake, stimulate postsynaptic dopamine receptors, or enhance dopamine receptor sensitivity.
Improvement has been seen in the small number of individual patients who received treatments that included at least 1 agent in this drug category.