A person affected by
myasthenia gravis may have difficulty in climbing stairs or rising
from chairs. Simple actions like lifting things or raising his arms
over his head may be tests of strength for him. His speech may begin
to sound nasal, since all the lower facial muscles may be involved.
Usually, the muscles that are first affected are those concerned
with eye movements, facial expressions, chewing, swallowing and
respiration. The person may have to support his chin with one hand
in order that he may be able to talk. There could be double vision,
drooping eyelids and eye wandering.
From the face, the
disease spreads to the neck, trunk and limb muscles. Weakness in the
neck may be mild or severe. It can be so severe that the person may
have difficulty holding his head erect. The heart usually remains
unaffected. The person may have respiratory problems. Respiratory
arrest may happen in very severe cases.
What happens is that the
muscles first fail to contract after prolonged use. They appear to
become weaker with repeated mild activities but seemingly regain
strength after rest. Eventually, muscular paralysis may result, with
degeneration of muscle fibers and infiltration of lymph cells.
When can it occur?
Myasthenia gravis can occur at any age. However, it is rare that
it sets in before age ten or after age seventy. Usually women are
more prone to it than men and it has been noted that the condition
is more prevalent in some families. Some symptoms may set in
suddenly, while some symptoms may remain in a person for twenty
years or so without any marked worsening. The latter is true in the
case of visual problems such as double vision and drooping eyelids.
Since myasthenia gravis is an autoimmune disorder where the
linkage between stimulus and response is broken, treatment includes
drugs that stimulate the transmission of nerve impulses. In very
severe cases, surgery is advised for removal of the thymus, if there
is thyroid tumor. Although death may result from sudden respiratory arrest, myasthenia gravis is not a fatal disease.