Marchiafava-Bignami: Clinical Case Description

INTRODUTION Marchiafava-Bignami disease is a very rare disorder characterized by demyelination and necrosis of the corpus callosum. Some times adjacent subcortical white matter may also be involved. The disease was first described in 1903 by Italian pathologists Ettore Marchiafava and Amico Bignami [1]. They described a man with alcohol use disorder who died of neurodegenerative condition, with refractory epileptic seizures and coma. At autopsy, the patient presented necrosis of the corpus callosum. The main pathologic changes seen in Marchiafava-Bignami include symmetrical demyelination and necrosis of the central part of the corpus callosum. Other structures of the central nervous system like putamen, optic chiasm and tracts, anterior commissure, cerebellar peduncles and cortical gray matter and U fibers may be involved [2]. The pathophysiology is unclear, but we know that Ethanol is an important risk factor for various brain disorders, depending on the amount and frequency of its use. The association of alcohol with B-complex hypovitaminosis, especially thiamine, can directly damage the corpus callosum, producing an initial phase of cytotoxic edema and breakdown of the blood-brain barrier. The consequences are demyelination, necrosis and subsequent atrophy. The neuroradiological classification of Marchiafava-Bignami shows two subtypes of the disease [3]. Type A, characterized by acute or subacute onset of consciousness impairment, pyramidal tract signs, limb hypertonia and seizures. In these cases there is extensive involvement of the corpus callosum. On magnetic ressonance imaging (MRI), hyperintense signal on T2 and FLAIR is observed in a large part of the corpus callosum. This type is associated with poor prognosis. In type B, there is preservation of the level of consciousness, with gait disturbance and signs of interhemispheric disconnection. In this type, the prognosis is better than in type A. Type B radiological findings are T2-weighted MR sequences partially involving the corpus callosum. There is a Variable clinical spectrum, defined by characteristics lesions in the corpus callosum. Early symptoms are typically mental, including mania, depression, paranoia and dementia. Sometimes the disease presents itself only as psychiatic signs and symptoms [4]. These patients are often malnourished and have water and electrolyte disorders. Treatment basically consists of replacing calories, good fluid and electrolyte replacement and supplementation of B complex vitamins, especially thiamine. Thiamine can be used in the folowing dose: 200 to 500 mg intravenously three times a day for 2 to 7 days. Lastly, an oral maintenance dose of 100 mg once each day [5]. Megaloblastic and macrocytic anemias linked to alcohol use disorder and malnutrition can be treated or prevented by supplementing with folic acid at 1 to 5 mg taken orally once daily. Research shows that steroid use is not effective [6].