What is (are) Alexander Disease ?
Alexander disease is one of a group of neurological conditions known as the leukodystrophies, disorders that are the result of abnormalities in myelin, the white matter that protects nerve fibers in the brain. Alexander disease is a progressive and often fatal disease. The destruction of white matter is accompanied by the formation of Rosenthal fibers, which are abnormal clumps of protein that accumulate in non-neuronal cells of the brain called astrocytes. Rosenthal fibers are sometimes found in other disorders, but not in the same amount or area of the brain that are featured in Alexander disease. The infantile form is the most common type of Alexander disease. It has an onset during the first two years of life. Usually there are both mental and physical developmental delays, followed by the loss of developmental milestones, an abnormal increase in head size, and seizures. The juvenile form of Alexander disease is less common and has an onset between the ages of two and thirteen. These children may have excessive vomiting, difficulty swallowing and speaking, poor coordination, and loss of motor control. Adult-onset forms of Alexander disease are less common. The symptoms sometimes mimic those of Parkinsons disease or multiple sclerosis, or may present primarily as a psychiatric disorder. The disease occurs in both males and females, and there are no ethnic, racial, geographic, or cultural/economic differences in its distribution.