Usually, a capillary bed separates arteries from veins, which protects the veins from the higher blood pressures that occur in arteries. In arteriovenous malformations, arteries are directly connected to veins, which increases the risk of venous rupture and hemorrhage. Arteriovenous malformations in the brain have a 2–4% chance of rupture each year. However, many arteriovenous malformations go unnoticed and are asymptomatic throughout a persons lifetime. A germinal matrix hemorrhage is bleeding into the brain of premature infants caused by the rupture of fragile blood vessels within the germinal matrix of premature babies. The germinal matrix is a highly vascularized area within an unborn infants brain from which brain cells, including neurons and glial cells, originate. Infants are at most risk to germinal matrix hemorrhages when they are born prematurely, before 32 weeks. The stresses exposed after birth, along with the fragile blood vessels, increase risk of hemorrhage. Signs and symptoms include flaccid weakness, seizures, abnormal posturing, or irregular respiration.CADASIL is an inherited disorder caused by mutations in the Notch 3 gene located on chromosome 19. The Notch 3 gene codes for a transmembrane protein whose function is not well-known. However, the mutation causes accumulation of this protein within small to medium-sized blood vessels. This disease often presents in early adulthood with migraines, stroke, mood disturbances, and cognitive deterioration. MRI shows white matter changes in the brain and also signs of repeated strokes. The diagnosis can be confirmed by gene testing.
The patient usually has a history of alcohol use disorder or malnutrition and neurological symptoms are sometimes present and can help lead to a diagnosis. MBD can be told apart from other neural diseases due to the symmetry of the lesions in the corpus callosum as well as the fact that these lesions dont affect the upper and lower edges.There are two clinical subtypes of MBD
Type A- Stupor and coma predominate. Radiological imaging shows involvement of the entire corpus callosum. This type is also associated with symptoms of the upper motor neurons.Type B- This type has normal or only mildly impaired mental status and radiologic imaging shows partial lesions in the corpus callosum. Treatment
Treatment is variable depending on individuals. Some treatments work extremely well with some patients and not at all with others. Some treatments include therapy with thiamine and vitamin B complex. Alcohol consumption should be stopped. Some patients survive, but with residual brain damage and dementia. Others remain in comas that eventually lead to death. Nutritional counseling is also recommended. Treatment is often similar to those administered for Wenicke-Korsakoff syndrome or for alcohol use disorder.Type A has 21% mortality rate and an 81% long-term disability rate. Type B has a 0% mortality rate and a 19% long-term disability rate. Recent Research
In a study published in 2015, a patient was observed to have MBD, but no history of excessive alcohol use. It is believed that he had protein, folic acid, and thiamine deficiencies, which are what caused the demyelination of the corpus callosum.