Prognosis

 

The expected future course of the disease depends on the subtype of the disease; the individual's sex, age, and initial symptoms; and the degree of disability the person has. Female sex, relapsing-remitting subtype, optic neuritis or sensory symptoms at onset, few attacks in the initial years and especially early age at onset, are associated with a better course. The average life expectancy is 30 years from the start of the disease, which is 5 to 10 years less than that of unaffected people. Almost 40% of people with MS reach the seventh decade of life. Nevertheless, two-thirds of the deaths are directly related to the consequences of the disease. Suicide is more common, while infections and other complications are especially dangerous for the more disabled. Although most people lose the ability to walk before death, 90% are capable of independent walking at 10 years from onset, and 75% at 15 years.

 

Epidemiology

 

MS is the most common autoimmune disorder of the central nervous system. As of 2010, the number of people with MS was 2–2.5 million (approximately 30 per 100,000) globally, with rates varying widely in different regions. It is estimated to have resulted in 18,000 deaths that year.[88] In Africa rates are less than 0.5 per 100,000, while they are 2.8 per 100,000 in South East Asia, 8.3 per 100,000 in the Americas, and 80 per 100,000 in Europe. Rates surpass 200 per 100,000 in certain populations of Northern European descent. The number of new cases that develop per year is about 2.5 per 100,000. Rates of MS appear to be increasing; this, however, may be explained simply by better diagnosis. Studies on populational and geographical patterns have been common and have led to a number of theories about the cause. MS usually appears in adults in their late twenties or early thirties but it can rarely start in childhood and after 50 years of age. The primary progressive subtype is more common in people in their fifties. Similar to many autoimmune disorders, the disease is more common in women, and the trend may be increasing. As of 2008, globally it is about two times more common in women than in men. In children, it is even more common in females than males, while in people over fifty, it affects males and females almost equally.

 

History

Medical discovery

 

The French neurologist Jean-Martin Charcot (1825–1893) was the first person to recognize multiple sclerosis as a distinct disease in 1868.[89] Summarizing previous reports and adding his own clinical and pathological observations, Charcot called the disease sclerose en plaques. The three signs of MS now known as Charcot's triad 1 are nystagmus, intention tremor, and telegraphic speech (scanning speech), though these are not unique to MS. Charcot also observed cognition changes, describing his patients as having a "marked enfeeblement of the memory" and "conceptions that formed slowly". Before Charcot, Robert Carswell (1793–1857), a British professor of pathology, and Jean Cruveilhier (1791–1873), a French professor of pathologic anatomy, had described and illustrated many of the disease's clinical details, but did not identify it as a separate disease. Specifically, Carswell described the injuries he found as "a remarkable lesion of the spinal cord accompanied with atrophy". Under the microscope, Swiss pathologist Georg Eduard Rindfleisch (1836–1908) noted in 1863 that the inflammation-associated lesions were distributed around blood vessels. During the 20th century theories about the cause and pathogenesis were developed and effective treatments began to appear in 1990s.

 

Historical cases

 

There are several historical accounts of people who lived before or shortly after the disease was described by Charcot and probably had MS. A young woman called Halldora who lived in Iceland around 1200 suddenly lost her vision and mobility but, after praying to the saints, recovered them seven days after. Saint Lidwina of Schiedam (1380–1433), a Dutch nun, may be one of the first clearly identifiable people with MS. From the age of 16 until her death at 53, she had intermittent pain, weakness of the legs, and vision loss—symptoms typical of MS. Both cases have led to the proposal of a "Viking gene" hypothesis for the dissemination of the disease. Augustus Frederick d'Este (1794–1848), son of Prince Augustus Frederick, Duke of Sussex and Lady Augusta Murray and the grandson of George III of the United Kingdom, almost certainly had MS. D'Este left a detailed diary describing his 22 years living with the disease. His diary began in 1822 and ended in 1846, although it remained unknown until 1948. His symptoms began at age 28 with a sudden transient visual loss (amaurosis fugax) after the funeral of a friend. During the course of his disease, he developed weakness of the legs, clumsiness of the hands, numbness, dizziness, bladder disturbances, and erectile dysfunction. In 1844, he began to use a wheelchair. Despite his illness, he kept an optimistic view of life. Another early account of MS was kept by the British diarist W. N. P. Barbellion, nom-de-plume of Bruce Frederick Cummings (1889–1919), who maintained a detailed log of his diagnosis and struggle. His diary was published in 1919 as The Journal of a Disappointed Man.