Amyotrophic Lateral Sclerosis

Amyotrophic Lateral Sclerosis (ALS), sometimes referred to as "Lou Gehrig's Disease," is a progressive fatal neuromuscular disease that attacks nerve cells and pathways in the brain and spinal cord. Motor neurons, among the largest of all nerve cells, reach from the brain to the spinal cord and from the spinal cord to muscles throughout the body with connections to the brain. When they die, the ability of the brain to start and control muscle movement dies with them. With all voluntary muscle action affected, ALS patients in the later stages are totally paralyzed; through it all, however, their minds remain unaffected.

Amyotrophic comes from the Greek language. "A" means no or negative. "Myo" refers to muscle, and "Trophic" means nourishment--"No muscle nourishment." When a muscle has no nourishment, it "Atrophies" or wastes away. "Lateral" identifies the areas in a person's spinal cord where portions of the nerve cells that nourish the muscles are located. As this area degenerates it leads to scarring or hardening ("Sclerosis") in the region.

Over 5,000 Americans are diagnosed with ALS each year. There is great variation in the course of the disease. Symptoms usually appear in individuals between the ages of 40-70, though the disease has been reported in both younger and older persons. Survival after the confirming diagnosis is, on average, two to five years. Progression of ALS varies with each individual; therefore, some will live longer--up to 10 years, and about five percent will exceed 12 years. In some cases, the disease seems to plateau. Many patients are able to live productive and satisfying lives especially with the use of assistive devices for daily living, and later in the disease, augmentative communication equipment.

Men and women are affected in almost equal numbers. Also, up to 10 percent of ALS cases are familial occurring more than once in a family lineage; but 90 percent of ALS cases show no hereditary pattern.

Approximately one-third of patients become aware of the onset of the disease when their hands become clumsy, causing difficulty in the performance of fine tasks. Another one-third experience

weakness in the legs and may trip because of mild foot drop. The

remaining one-third notice slowing of speech or difficulty in

swallowing. ALS may be present for some time before any

symptoms are noticed. This lack of noticeable symptoms occurs

because the lost or damaged nerve cells are compensated for by

nerve cells that remain functioning. One early symptom is

generalized fatigue. As muscle cells deteriorate, patients may

experience stiffness or occasional jerking of the arms or legs

resulting from spasticity (muscle tenseness). Often symptoms begin

in the hands and feet, then travel inward toward the center of the

body. One side is usually more affected. Paralysis eventually may

be virtually complete, except for the muscles of the eyes. Anal and

bladder muscles and function are not usually affected.

There is no specific clinical test that can identify ALS. Diagnosis is

made by a neurologist through a physical examination, a thorough

patient medical history, and neurological testing. Diagnostic testing

often includes the electromyogram (EMG) to test muscle activity,

CT Scan, MRI (Magnetic Resonance Imaging), muscle and/or

nerve biopsy, and extensive blood work.

While it is true that there is no cure for ALS, much can be done to

help the patient live with the disease. Treatment aimed at relieving

symptoms can be very effective. Generally, patients should

continue usual daily activities, stopping before they become

fatigued. Patients should be encouraged to set their own limits of

exertion, and to plan how they will use their energy and strength.

The physician will probably suggest exercises, including breathing

exercises, to strengthen unaffected or less-affected muscles. These

exercises are not vigorous or tiring, but are intended to help

maintain mobility and prevent joint stiffness and muscle

contracture.

Various devices such as foot-drop braces, hand splints, limb

supports or wheelchairs enable the patient to remain as

independent as possible. Good skin care, massage and knowledge

of proper body positioning can prevent sores for those who are

confined to bed for lengthy periods of time. If bowel and bladder

function are affected by immobility, increasing daily fluid intake

should improve the situation or the doctor may prescribe stool

softeners, bulk formers or laxatives.

A palate lift may help if there are speech problems, and soft

foods are indicated if the patient has difficulty in swallowing.

Because ALS selectively destroys the motor neurons in the

nervous system, several hypotheses have been put forth as to the

cause or causes of ALS. Researchers are exploring such areas as

genetic factors, susceptibility genes, excitotoxicity, and premature

cell death.

In 1991, a team of ALSA-funded researchers linked familial

ALS to chromosone 21. In 1993 the research team identified a

defective SOD1 gene on Chromo-sone 21 as responsible for

many cases of familial ALS. Further study indicated structural

defects in the SOD (super oxide dismutase) enzyme which

reduces the enzyme's ability to protect against free radical damage

to motor neurons.

In January 1996, a team of researchers reported that their

studies suggest that the SOD1 gene mutations may enhance the

ability of the SOD enzyme to act as a "peroxidase," that is,

oxidizing and thereby damaging cell components. These studies

open up possibilities for possible therapies or strategies to

effectively mediate the effects of ALS. But much more research on

the SOD enzyme is needed.

Clinical trials of selected neurotrophic and growth factors are

continuing as biotechnology companies search for possible

therapies for ALS.

After 127 plus years, there is a first-ever treatment for ALS. It is

Rilutekr, manufactured by Rhone-Poulenc Rorer. The drug, an

antiglutamate, extends survival in ALS patients by an average three

months. The drug was approved by the FDA in December 1995

and became available by prescription in January 1996.

In addition, two other potential treatments could be approved

for marketing by 1997, pending outcome of clinical data and FDA

review. These are Myotrophin, a development from Cepalon, Inc.,

and BDNF (brain derived neurotrophic factor) being tested by

Amgen-Regeneron Partners. Both BDNF and Myotrophin appear

to slow progression of the disease in distinct areas according to

clinical trial data thus far. BDNF effects are shown in a slowing of

the deterioration of breathing capacity; Myotrophin appears to

slow the progression of muscle deterioration. Therefore, both have

demonstrated the capacity to extend quality of life in the ALS

patient.

Amyotrophic lateral sclerosis (ALS) is a fatal neurological disorder, characterized

by progressive degeneration of motor cells in the spinal cord and brain.

When the motor neuron cell can no longer send the impulses to the muscles there is

increased muscle weakness, especially in the arms and legs, speech, swallowing,

breathing. When muscles no longer receive the messages they require to function,

they begin to atrophy (waste away). ALS is very often referred to as "Lou Gehrig's

disease." Neither its cause or cure is known. Three known classifications of ALS

have been described:

Sporadic - the most common form of ALS in the United States

Familial - suggest genetic dominant inheritance and accounts for a very

small number of cases in the United States. Familial ALS requires further

investigation before the significance of the hereditary factor can be firmly

established.

Guamanian - an extremely high incidence of ALS has been observed in

Guam and the Trust Territories of the Pacific.

At the onset of ALS the symptoms may be so slight that they are frequently

overlooked. With regard to the progression of the illness, and the appearance of

symptoms, the course of the disease may include the following:

twitching and cramping of muscles, especially those in the hands and feet

impairment of the use of the arms and legs

"thick speech" and difficulty in projecting the voice

in more advanced stages, shortness of breath, difficulty in breathing and

swallowing

ALS is individual in each person -- in the area of the body affected as well as in the

rate of progression.

It is important to stress that ALS does not affect the intellectual functioning. Nor

does it interfere with the ability to taste, see, smell, hear or recognize touch.

Symptoms of the disease

What is ALS?

Amyotrophic lateral sclerosis (ALS), often referred to as "Lou Gehrig's disease," is

a progressive fatal neuromuscular disease that attacks nerve cells and pathways in

the brain to the spinal cord. Motor neurons, among the largest of all nerve cells,

reach from the brain to the spinal cord and from the spinal cord to the muscles

throughout the body with connections to the brain. When they die, as with ALS, the

ability of the brain to start and control muscle movement dies with them. With all

voluntary muscle action affected, patients in the later stages are totally paralyzed;

yet, through it all, their minds remain unaffected.

A-myo-trophic comes from the Greek language. "A" means no or negative.

"Myo" refers to muscle, and "Trophic" means nourishment---"No muscle

nourishment." When a muscle has no nourishment, it "atrophies" or wastes away.

"Lateral" identifies the areas in a person's spinal cord where portions of the nerve

cells that nourish the muscles are located. As this area degenerates it leads to

scarring or hardening ("sclerosis") in the region.

Incidence of ALS

ALS is one of the most devastating of disorders which affect the function of nerves

and muscles. Once thought rare, it is now fairly common. According to the United

States National Institutes of Health, nearly 5,000 people in the U.S. are newly

diagnosed with ALS each year. (That's about 13 new cases a day!) It is estimated

that as many as 30,000 Americans have the disease at any given time. And that

some 300,000 men and women who are alive and apparently well in the country

today will die with ALS unless a cure or prevention is found.

Most who develop ALS are between the ages of 40 and 70. There are, however,

cases of the disease attacking persons in their twenties and thirties. Generally,

though, ALS occurs in greater percentages as men and women grow older. It was

once believed that men developed ALS more frequently than women. That no

longer appears to be the case, and today both sexes are affected in nearly equal

numbers.

With recent advances in research and improved medical care, many ALS patients

are living longer and more productive lives. Half of all affected live at least three or

more years after diagnosis. Twenty percent live five years or more; up to ten

percent will survive more than ten years.

Forms of ALS

The most common form of ALS in the United States is known as "sporadic" ALS.

It may affect anyone, anywhere.

"Familial" ALS suggests the disease is inherited, although no heredity pattern exists

in the majority of ALS cases. Only about five to ten percent of all ALS patients

appear to have some kind of genetic or inherited component. In those families,

there is a 50 percent chance the offspring will have the disease.

Other terms which have been used to categorize variants of the classical form of

ALS include spinal muscular atrophy, progressive bulbar palsy and lateral sclerosis.

Other variants of ALS whose prognosis is better and whose relationship to ALS is

not yet determined include primary lateral sclerosis, juvenile muscular atrophy and

benign facial amyotrophy.

Symptoms of ALS

Early symptoms vary with each individual, but usually include tripping, dropping

things, abnormal fatigue of the arms and/or legs, slurred speech, muscle cramps and

twitches and uncontrollable periods of laughing or crying.

The hands and feet may be affected first, causing difficulty in walking or using the

hands for the activities of daily living such as dressing, washing and buttoning

clothes.

As the weakening and paralysis continue to spread to the muscles of the trunk of

the body the disease eventually affects swallowing, chewing and breathing. When

the breathing muscles are attacked, the patient faces permanent ventilatory support

in order to survive.

Since ALS attacks only motor neurons, the sense of sight, touch, hearing, taste and

smell and muscles of the eyes and bladder are generally not affected.

The mind, though, is not impaired and remains sharp despite the progressive

degenerating condition of the body.

Diagnosis of ALS

ALS is a very difficult disease to diagnose. There is no one test or procedure to

ultimately establish the diagnosis of ALS. It is through a clinical examination and

series of diagnostic tests, often ruling out other diseases that mimic ALS, that a

diagnosis can be established. A comprehensive diagnostic workup includes most, if

not all, of the following procedures: electrodiagnostic tests including

electomyography (EMG) and nerve conduction velocity (NCV), blood and urine

studies including high resolution serum protein electrophoresis, thyroid and

parathyroid hormone levels, 24 hour urine collection ...

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