IN ORDER to establish the diagnosis of multiple sclerosis, certain basic facts must be borne in mind:
1. Multiple sclerosis is characterized by the scattered occurrence of demyelinated patches in the white matter throughout the central nervous system. These patches, or plaques, develop in a characteristic way. The myelin sheaths are the first structures involved; they are followed by lymphocyte and plasma cell infiltration, by microglial and astrocytic proliferation, fat-granule-cell response, and connective tissue reactions.1 Axis-cylinders are damaged to a less degree; sometimes they are naked but not injured at all. The ganglion cells, even in areas with active degeneration, show no impairment. However, the spinal nerve roots are sometimes affected.
2. The plaques include sensory and motor pathways.
3. The neurological symptoms vary greatly, according to the location of the lesions within the central nervous system. Clinically, certain types of the disease may be distinguished, such as