Multiple sclerosis is initially characterized by weakness, numbness, tingling, or unsteadiness in a limb; spastic paraparesis may follow. This common neurologic disorder of unknown cause has its greatest incidence in young adults.
Epidemiologic studies indicate that multiple sclerosis is much more common in persons of western European lineage who live in temperate zones. No population with a high risk for multiple sclerosis exists between latitudes 40 °N and 40 °S.
Genetic, dietary, and climatic factors cannot account for these differences. There may be a familial incidence of the disease, since affected relatives are sometimes reported. The strong association between multiple sclerosis and specific HLA antigens (HLA-DR2) provides support for a theory of genetic predisposition. Many believe that the disease has an immunologic basis. Pathologically, Focal-often perivenular-areas of demyelination with reactive gliosis are found scattered in the white matter of brain and spinal cord and in the optic nerves.
A. Symptoms and Signs: The common initial presentation is weakness, numbness, tingling, or unsteadiness in a limb; spastic paraparesis; retrobulbar neuritis; diplopia; disequilibrium; or a sphincter disturbance such as urinary urgency or hesitancy. Symptoms may disappear after a few days or weeks, although examination often reveals a residual deficit.
In most patients, there is an interval of months or years after the initial episode before new symptoms develop or the original ones recur. Eventually, however, relapses and usually incomplete remissions lead to increasing disability, with weakness, spasticity, and ataxia of the limbs, impaired vision, and urinary incontinence. The findings on examination at this stage commonly include optic atrophy, nystagmus, dysarthria, and pyramidal, sensory, or cerebellar deficits in some or all of the limbs. Read the rest of this entry »