ESSENTIALS OF DIAGNOSIS
Multiple sclerosis (MS) most often affects Caucasian females, with onset of symptoms in the second and third decades of life.
No definitive etiology has been determined.
There are four clinical patterns; the most common is relapsing-remitting MS.
Magnetic resonance imaging (MRI) of the brain and spinal cord is the most useful diagnostic tool for detecting MS.
Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system that most commonly affects young to middle-aged adults. It is characterized by multiple white matter plaques of demyelination that pose major threats to function by producing impairments to cognition, vision, speech, swallowing, muscle function, and bowel and bladder function. Because of its chronic, progressive nature, disability may evolve throughout the course of a patient’s lifetime. The costs of disease, both direct and indirect, are immense. Direct medical costs have been estimated to be in excess of $10 billion per year in the United States. Indirect costs include those related to employment (reduced, or unemployment), disability-related assistive devices and home modifications, and personal care. Physiatric and rehabilitative intervention is crucial to ensure functional and symptomatic improvement over the course of a patient’s life, to improve quality of life, and to decrease the burden of disease.
Most patients with MS are diagnosed while in their 20s and 30s, traditionally prime working and childbearing years. Although the incidence of disease is difficult to ascertain, it is estimated that 400,000 people in the United States are living with MS. Worldwide, prevalence probably exceeds 2.5 million people. Areas with the highest prevalence include northern Europe, southern Australia, and the middle portion of North America. Additionally, MS is one of the most common causes of nontraumatic disability in young adults. The disease is more common in women, with a female-to-male ratio of approximately 2–3:1. Caucasians also tend to be affected more than blacks and Asians.
Although the cause of MS remains unknown, several different factors appear to play a role. One theory focuses on environmental factors associated with geographic location. Living farther away from the equator has been found to convey a higher risk of developing MS, although the Inuit population is an exception. A second notable difference relates to migration patterns. Researchers have noted that the risk of MS decreases when individuals migrate from areas of high to low geographic risk, but the opposite is not true. Although the relationship between distance from the equator and MS is unclear, the significance of vitamin D–promoting sun exposure in relation to development of MS has gained prominence. There is a known increased risk of development of MS in those with low levels of vitamin D. Research is ongoing to determine the effect of vitamin D levels on symptoms in patients previously diagnosed with the disease. Giving additional credence to the environmental influence is the variability seen in disease manifestations and age of onset. ...