ABSTRACT
Multiple sclerosis disease characteristics Multiple sclerosis (MS) is the most common nontraumatic neurological illness in young and middle-aged adults, with disease onset typically between ages 20 and 40 (Rao, Leo, Bernardin, & Unverzagt, 1991). Current epidemiological studies indicate that women are approximately twice as likely to suffer from MS as men (Kraft. 1981), and MS is more prevalent in certain geographic regions (Rumrill, Kaleta, & Battersby, 1996). It is primarily a white matter disease that particularly affects periventricular areas of the brain bilaterally. MS causes destruction of neuronal myelin sheaths, which are integral to the normal transmission of nerve impulses (Herndon, 2003), and has also recently been associated with axonal damage (Davie, Barker, Thompson, Tofts, McDonald, & Miller, 1997; Trapp, Peterson, Ransohoff, Rudick, Mork, & Bo, 1998). The resulting widespread lesions in the central nervous system (CNS), also known as sclerotic plaques, can cause motor, cognitive, and psychiatric problems (Brassington & Marsh, 1998), with high variability in symptom presentation between individuals (Gordon, Lewis, & Wong, 1994). Currently, the disease course is classified as relapsing remitting (RRMS), secondary progressive (SPMS) or primary progressive multiple sclerosis (PPMS). Previously, individuals with either SPMS or PPMS were classified as chronic progressive (CPMS), but this classification system was eliminated after increasing reports of differences in pathology (Lublin & Reingold, 1996). The wide range in symptoms and disease course creates a significant obstacle in understanding the disease process and identifying effective treatments. While the etiology remains elusive, MS is currently thought to be the result of a combination of immunologic, genetic, and viral factors (Rumrill et a1., 1996).
