<prompt> Multiple sclerosis is characterized by all EXCEPT -DemyelinationGrey-tan plaques in the white matterIncreased protein concentration in CSFOligodendrocytes  <response>: i.e. Oligodendrocytes: 884-Harsh Mohan 6th 1310-1312-Robbins Cotran 8thMULTIPLE SCLEROSIS - is an autoimmune demyelinating disorder characterized by distinct episodes of neurologic deficits separated in time, attributable to white matter lesions that are separated in spacePathologic hallmark is the presence of many scattered discrete areas of demyelination termed plaquesMORPHOLOGIC FEATURESGrossly - plaque appears as grey-pink swollen sharply defined usually bilaterally symmetric areas in the white matterMicroscopically - according to the age of the plaque1. Inactive enlarging plaque, the histologic features are an accumulation of lymphocytes and macrophages around venules and at the plaque margin where demyelination is occurring. In addition, there is a loss of oligodendrocytes and presence of reactive astrocytes with numerous lipid-laden macrophages microglia in the plaque. The axons in the plaque are generally intact.2. In old inactive plaque - there is no perivascular inflammatory cell infiltrate and nearly total absence of oligodendrocytes. Demyelination in the plaque area is complete as there is an only limited regeneration of myelin gliosis is well developed but astrocytes are less prominent. Some axonal loss may be present. 