Multiple Sclerosis

Multiple sclerosis

Definition:

Multiple Sclerosis is a demyelinating disease cause a widespread degeneration of the central nervous system (CNS) which gradually results in severe neurological deficits. The disease is characterized by remissions and relapse, erratic onset and duration is flare up acutely. Each relapse may involve different area in white matter in central nervous system (CNS) .

Etiology:

There is may involve in genetic and environmental factor, which may cause immunologically mediated inflammatory response with CNS . The immune response in mediating tissue damage, and the extent to which these change are the cause or consequence of myelin injury, remain too established. Exposure to other viral illness such as measles, mumps, and rubella rather late in childhood may be a factor in those who are at risk of developing the disease. The further evidence of genetic susceptibility is provided by epidemiological studies within and between ethnic. The risk is raise group for offspring and for sibling of affected persons. Other than that, environment may be relatively more protective. Age is also a factor in immigration populations. Dean (1967) said the multiple sclerosis is higher for who migrated as adults rather than as children. Furthermore, the multiple sclerosis does not have a single cause . A new episode of demyelination is more likely to occur following a viral infection but no single agent has implicated.

Pathology:

Demyelination is a disintegrated of the myelin sheath cause by an inflammatory and destruction process, the axon being partly or completely denuded. The features of multiple sclerosis lesions are perivascular inflammation followed by myelin depletion, oligodendrocytes loss and astroglial proliferation. The initial stage characterized by the accumulation of inflammatory cells, lymphocytes and monocytes around venules within the CNS. Inflammation may cause a function block in conduction through myelinated axons. Next, there is active destruction of the oligodendrocyte and its myelin sheath as a result of contact with macrophanges and microglia . This followed by depletion of oligodendrocytes in which denuded axons re seen within the lesion. Finally, the lesion heals by scar formation dependent upon astrocytic reactivity, producing hardened patches or plaques from which the disease gets its name. the most common side of plaques are in the boundary grey matter in the cerebellum, cerebellar white matter, optic nerves, cervical portion of spinal cord and brain stem.

Multiple sclerosis Diagnostic Criteria

Numerous different diagnostic criteria have been proposed over the year. The criteria that colleagues formulated in 1965 was define of relapses worsening symptom lasting longer than 24 hours and separated by 1 month is still used in practice and research protocols today.