No one knows exactly how many people have MS. It is
believed that, currently, there are approximately
250,000 to 350,000 people in the United States with
MS diagnosed by a physician. This estimate suggests
that approximately 200 new cases are diagnosed each
week.
Most people experience their first symptoms of MS
between the ages of 20 and 40, but a diagnosis is
often delayed. This is due to both the transitory
nature of the disease and the lack of a specific
diagnostic test-specific symptoms and changes in the
brain must develop before the diagnosis is confirmed.
Although scientists have documented cases of MS
in young children and elderly adults, symptoms
rarely begin before age 15 or after age 60. Whites
are more than twice as likely as other races to
develop MS. In general, women are affected at almost
twice the rate of men; however, among patients who
develop the symptoms of MS at a later age, the
gender ratio is more balanced.
MS is five times more prevalent in temperate
climates-such as those found in the northern United
States, Canada, and Europe-than in tropical regions.
Furthermore, the age of 15 seems to be significant
in terms of risk for developing the disease: some
studies indicate that a person moving from a high-risk
(temperate) to a low-risk (tropical) area before the
age of 15 tends to adopt the risk (in this case, low)
of the new area and vice versa. Other studies
suggest that people moving after age 15 maintain the
risk of the area where they grew up.
These findings indicate a strong role for an
environmental factor in the cause of MS. It is
possible that, at the time of or immediately
following puberty, patients acquire an infection
with a long latency period. Or, conversely, people
in some areas may come in contact with an unknown
protective agent during the time before puberty.
Other studies suggest that the unknown geographic or
climatic element may actually be simply a matter of
genetic predilection and reflect racial and ethnic
susceptibility factors.
Periodically, scientists receive reports of MS
"clusters." The most famous of these MS "epidemics"
took place in the Faeroe Islands north of Scotland
in the years following the arrival of British troops
during World War II. Despite intense study of this
and other clusters, no direct environmental factor
has been identified. Nor has any definitive evidence
been found to link daily stress to MS attacks,
although there is evidence that the risk of
worsening is greater after acute viral illnesses.
MS is a life-long chronic disease diagnosed
primarily in young adults who have a virtually
normal life expectancy. Consequently, the economic,
social, and medical costs associated with the
disease are significant. Estimates place the annual
cost of MS in the United States in the billions of
dollars.
.gif){kind=small}
.gif){kind=small}
.GIF){kind=small}
.gif){kind=small}
.jpg){kind=small}