Amyotrophic Lateral Sclerosis
Amyotrophic lateral sclerosis (ALS) is a progressive
disease of the nervous system. The cause is not known and there is no
cure, although progress is being made on both fronts. ALS is also known as
Lou Gehrig's disease after the famous baseball player who died from it.
ALS attacks motor neurons, which are among the largest
of all nerve cells in the brain and spinal cord. These cells send messages
to muscles throughout the body. In ALS, motor neurons die and the muscles
weaken as they lose their ability to move. Eventually, most muscle action
is affected, including those which control swallowing and breathing, as
well as major muscles in the arms, legs, back and neck. There is, however,
no loss of sensory nerves, so people with ALS retain their sense of
feeling, sight hearing, smell and taste. The mind is not affected by this
disease and people with ALS remain fully alert and aware of events. The
course of ALS is extremely variable and it is difficult to predict the
rate of progression in any single patient. For the majority of people with
ALS, weakness tends to progress over a three-to-five year period.
ALS can strike anyone, at any age, but generally ALS
occurs between the ages of 40 and 70. According to the National Institutes
of Health, some 4,600 people in the United States are newly diagnosed with
ALS each year. About 4 to 6 people per 100,000 worldwide get ALS. In a
small percentage of patients, ALS is genetic.
The first signs of ALS are often arm and leg weakness,
muscle wasting and faint muscle rippling. These symptoms occur because
muscles are no longer receiving the nutrient signals they need for growth
and maintenance- a result of motor neurons dying. ALS nerve degeneration
may also cause muscle cramps and vague pains, or problems with speech and
swallowing. Some people with the disease may lose some control over their
emotional responses. They may laugh or cry much more easily than in the
past. Eventually, all voluntary muscle action is affected.
There is no specific test for diagnosing ALS. However,
several tests- including nerve conduction studies and elctromyagram (EMG)-
are used to measure how well and quickly the nerves are working. Ruling
out other causes of muscular weakness is important because ALS often
mimics other treatable diseases. Diagnosis requires special skills and
neurologic tests. People with ALS symptoms usually are referred to
neurologists, who specialize in the nervous system. Diagnosis may take
several months since an important part of the diagnostic process is to
confirm disease progression.
The cause of ALS is unknown. It attacks its victims at random. However,
it was recently discovered that five to ten percent of those with ALS show
a definite genetic pattern. In this rare form, about one-half of the
offspring may develop ALS. These people show a gene defect that affects an
enzyme called superoxide dismutate. This enzyme eliminates toxic
substances called free radicals. Free radicals can cause nerve cells to
die and are associated with a number of diseases and even implicated in
aging itself. For most people with ALS, the vast majority of their
children are not at any greater risk of developing this disease than the
general population. This type of ALS is often called "sporadic ALS"
due to its unpredictable nature.
ALS researchers have found no difference between the symptoms and
disease progression in the sporadic and genetic forms of ALS. Therefore,
since the genetic and acquired forms of ALS appear to be similar, an
understanding of the cause of the genetic form could lead to treatment for
all forms of the disease.
While there is no cure for ALS, research to solve the ALS puzzle is
ongoing. Scientific advances have led to approval of the first treatment
for the disease- a medication that may increase survival time. Other
treatments under investigation include several nerve growth factors which
may help maintain quality of life by maintaining nerve function. While
each of these therapies represent a step forward for people with ALS, a
cure remains to be discovered.
For the majority of people with ALS, the primary treatment remains the
management of ALS symptoms. Patients need to take an active role in the
design of their treatment regimen. Ideally, ALS management involves
physical, occupational, speech, respiratory and nutrition therapy. For
instance, certain drugs and the application of heat or whirlpool therapy
may help to relieve muscle cramping. Exercise, however, is recommended in
moderation. Drugs also may be used to help combat fatigue, but in some
patients may worsen muscle cramps.
As the disease progresses, various assistive devises will help persons
with ALS maintain their independence and endure personal safety. For
example, an ankle/foot brace can improve function and conserve energy, as
well as help avoid injury. When neck, trunk and shoulder weakness makes
walking or sitting difficult, cervical collars, perhaps with an additional
chest and head strap, provide helpful support. A reclining Chair is
preferable to a headrest to relieve fatigue of neck muscles. There are
also numerous devises to assist in feeding, dressing and maintaining
personal hygiene. Eventually, more substantial equipment, such as
wheelchairs, scooters, lifts and hospital beds may be required.
It is important to know that speech therapists can help with speech and
swallowing difficulties as they develop. Also, drug treatments can help
patients who develop excessive saliva and drooling. Family members of
people with ALS should be instructed in the Heimlich maneuver to provide
assistance in a life-threatening choking episode. Feeding tubes may be
necessary to maintain nutrition, as may breathing devises when the disease
affects the muscles of the chest. However, with these supportive devices,
there are physical, emotional and financial implications, and their use
should be discussed with a physician well in advance of when the need
arises. Managing the symptoms is a process that is challenging for people
with ALS, their caregivers, and their medical team.
Of all the disabilities that affect a person with ALS, one of the most
devastating and most common is the progressive loss of the ability to
communicate. However, advances in computer technology mean that persons
with ALS today have vital new electronic communications options that can
be adapted to their individual capabilities.
Significant progress is being made in the study of ALS.
Although there is still no cure, recent clinical trails have shown that
some drugs affect cell activity and may increase the survival time for
people with ALS. Newly developed animal models of the genetic form of the
disease, so-called transgenic ALS mice, offer neurologic researchers the
ability to test therapies in mice. There is great hope that this and other
neuroscientific advances will lead to a cure in humans. Talk with your
doctor about being involved in future clinical trails or about the drugs
currently available for the treatment of this disease.