Do viral infections trigger severe demyelinating disorders of the Central Nervous System? An assessment with a special focus on Multiple Sclerosis and Acute Disseminated encephalomyelitis

Bachelor Thesis from the year 2004 in the subject Biology - Neurobiology, grade: 1.2 (A), Imperial College London, language: English, abstract: Multiple Sclerosis (MS) is a progressive, disabling, neurological illness that affects the brain and spinal cord. Nerve cells, which are usually surrounded by oligodendrocyte myelin, are damaged, die and won't be replaced when the Central Nervous System (CNS) is inflamed. As a consequence, progressive loss of the lipid rich myelin sheath surrounding axons result in disrupted, lower fidelity action potentials and slow signal conduction. MS is thought to have a number of causes, however, none has been identified as the true causative agent. MS is the most common neurological disease in people below 30 and it affects more than 1 million young adults worldwide. It is five times more common in temperate climates than in tropical areas and women are affected twice as often as men are. Scientists suspect that MS develops because of the influence of genes acting together. However, a common belief held by many scientists is that not only the genetic influences, but also environmental influences, especially those of viral infections, which trigger the disease. This review considers the evidence in existence implicating viral responsibility in the onset of myelination disorders.