In 2 cases that have come to our attention, the clinical manifestations were essentially those of bilateral frontal lobe disease: motor and mental slowness, apathy, prominent grasping and sucking reflexes, gegenhalten, incontinence, and a slow, hesitant, wide-based gait. In both these cases, the neurologic abnormalities evolved over a period of about 2 months, and both patients recovered within a few weeks of hospitalization. Death occurred several years later as a result of liver disease and subdural hematoma, respectively. In each case, autopsy disclosed an old lesion typical of Marchiafava-Bignami disease confined to the central portion of the most anterior parts of the corpus callosum, but one had to look closely to see the gray line of gliosis.
In view of the great variability of the clinical picture and the obscuration in many patients of subtle mental and neurologic abnormalities by the effects of chronic inebriation and other alcoholic neurologic disorders, the diagnosis of Marchiafava-Bignami disease is understandably difficult. In fact, it is rarely made during life, but the CT and MRI have disclosed typical but unsuspected examples (see Kawamura et al). In some cases studied sequentially, MRI has disclosed demyelination, swelling, and necrosis of the corpus callosum with extension toward the subcortical white matter. In a few cases these findings have reversed over time after vitamin therapy, leaving residual callosal atrophy (Gambini et al). The occurrence, in a chronic alcoholic, of a frontal lobe syndrome or a symptom complex that points to a diagnosis of frontal or corpus callosum tumor but in whom the symptoms remit should suggest the diagnosis of Marchiafava-Bignami disease. The image appearance may be easily mistaken for multiple sclerosis, gliomatosis cerebri, or progressive multifocal leukoencephalopathy.
Originally, Marchiafava-Bignami disease was attributed to the toxic effects of alcohol, but this is an unlikely explanation in view of the prevalence of alcoholism and the rarity of corpus callosum degeneration. Furthermore, the distinctive callosal lesions have not been observed with other neurotoxins. Very rarely, undoubted examples of Marchiafava-Bignami disease have occurred in abstainers, so that alcohol cannot be an indispensable factor. A nutritional etiology has been invoked, but the putative factor that is deficient has not been determined. This view is underscored by reports of improvement in a few, but not all, cases following administration of thiamine. The mechanisms involved in the selective demyelination and noninflammatory necrosis of particular areas of white matter remain to be elucidated. Perhaps, when its mechanism becomes known, Marchiafava-Bignami disease, like central pontine myelinolysis (which it resembles histologically), will have to be considered in a chapter other than one on nutritional disease.
PROTEIN-CALORIE MALNUTRITION AND DEVELOPMENTAL DELAY (SEE ALSO CHAP. 37)
There is increasing evidence that severe dietary deprivation during critical phases of brain development may result in permanent impairment of cerebral function and in developmental delay. Because there are an estimated 100 million children in the world who are undernourished and suffer from varying degrees of protein, calorie, and other dietary inadequacies, this is one of the most pressing problems in medicine and society.