Amyotrophic Lateral Sclerosis (ALS) is not contagious. It is a degenerative disease that affects the brain and spinal cord. A chronic disorder, it causes a loss of control of voluntary muscles. The nerves controlling speech, swallowing, and limb movements are often affected. Unfortunately, a cure has not yet been found for the disease.
ALS is also known as Lou Gehrig’s disease. The famed baseball player was diagnosed with the disease in 1939.
ALS can be classified as either sporadic or familial. Ninety percent of cases are sporadic. That means no specific cause is known.
There is a genetic explanation for ALS in less than 10 percent of cases. Other causes of ALS are not well understood. Some factors which scientists think might contribute to ALS include:
- free radical damage
- an immune response that targets motor neurons
- imbalances in the chemical messenger glutamate
- a build-up of abnormal proteins inside nerve cells
The Mayo Clinic has also identified smoking, lead exposure, and military service as possible risk factors for this condition.
ALS usually occurs between the ages of 50 and 60, although symptoms can occur earlier. ALS is slightly more common in men than in women.
Every year about 5,000 people in the United States are diagnosed with ALS. The Mayo Clinic estimates that around 20,000 Americans are currently living with the disorder. Worldwide, ALS affects approximately 5 out of every 100,000 people. It is the most common cause of neurological death in Canada. ALS affects people of all racial, social, and economic groups.
ALS is becoming more common. This may be because the population is aging. It could also be due to increasing levels of an environmental risk factor that has not yet been identified.
Both sporadic and familial ALS are associated with a progressive loss of motor neurons. Cortical motor neurons, anterior horn cells, and bulbar motor neurons can all be lost.
The symptoms of ALS depend on what areas of the nervous system are affected. These will vary from person to person.
The medulla is the lower half of the brainstem. It controls many of the body’s autonomic functions. These include breathing, blood pressure, and heart rate. Damage to the medulla can cause:
- slurred speech
- difficulty swallowing
- emotional lability
- tongue wasting
- excess saliva
- problems breathing
The corticospinal tract is a part of the brain made up of nerve fibers. It sends signals from your brain to your spinal cord. ALS damage to the corticospinal tract causesspastic limb weakness.
The anterior horn is the front part of the spinal cord. Degeneration here can cause:
- limp muscles (flaccid weakness)
- muscle wasting
- breathing problems caused by weakness in the diaphragm and other respiratory muscles
Early signs of ALS may include problems performing the tasks of everyday life. For example, you may have difficulty climbing stairs or getting up from a chair. You might also have problems speaking and swallowing, or weakness in your arms and hands. Early symptoms are usually focal, found in specific sites of the body. They also tend to happen only on one side. In other words, they are asymmetrical.
As the disease progresses, symptoms generally spread to both sides of the body. Bilateral muscle weakness becomes common. This can lead to weight loss from muscle wasting. The senses, the urinary tract, and bowel function usually remain intact.
Approximately 30 to 50 percent of people suffering from ALS have some cognitive impairment. Behavioral changes can also occur without mental decline. Emotional lability can occur in all ALS sufferers, even those without dementia. This condition is characterized by excessive emotional reactions such as laughing or crying.
Inattention and slowed thinking are the most common cognitive symptoms of ALS. ALS-related dementia can also occur if there is cell degeneration in the frontal lobe. ALS-related dementia is most likely to occur when there is a family history of dementia. Poor breathing, bulbar onset ALS, and being older than 60 are also risk factors for dementia.
According to the Amyotrophic Lateral Sclerosis Society of Canada (ALSSC), people with ALS and cognitive decline have shorter life spans than those who don’t suffer from cognitive impairment.
ALS is usually diagnosed by a neurologist. There is no specific test for ALS. The process of establishing a diagnosis can take anywhere from weeks to months.
Doctors may start to suspect ALS when a patient has progressive neuromuscular decline. They will watch for increasing problems with symptoms such as muscle weakness, wasting, atrophy, twitching, cramps, or contractures.
These symptoms can also be caused by a number of conditions. Therefore, a diagnosis requires the doctor to rule out other health problems. This is done with a series of diagnostic tests including:
- EMG to evaluate electrical activity of muscles
- nerve conduction studies to test nerve function
- an MRI that shows which parts of the nervous system are affected
- blood tests to evaluate general health and nutrition
Genetic tests may also be useful for patients with a family history of ALS.
As ALS progresses, it becomes more difficult to breathe and digest food. The skin and subcutaneous tissues are also affected. Many parts of the body deteriorate, and all of them must be treated appropriately.
Because of this, a team of doctors and specialists often work together to treat ALS patients. Specialists involved in the ALS team might include:
- a neurologist who is skilled in management of ALS
- a physiatrist
- a nutritionist
- a gastroenterologist
- an occupational therapist
- a respiratory therapist
- a speech therapist
- social, mental health, and pastoral care workers
Family members should talk to patients about their care. Patients may need support when making medical decisions.
Riluzole (Rilutek) is currently the only drug approved for the treatment of ALS. It can prolong life by several months, but it cannot eliminate symptoms entirely. Other medications may be used to treat the symptoms of ALS. These include:
- cramping and spacticity – quinine bisulphate, baclofen, and diazepam
- pain management – NSAIDs, gabapentin (anticonvulsant), tricyclic antidepressants, and morphine
- emotional lability – Neurodex (a combination of vitamins B1, B6 and B12)
Scientists are investigating the use of coenzyme Q-10, COX-2 inhibitors, creatine, and minocycline for a subtype of hereditary ALS. However, they have not yet been proven effective.
Stem cell therapy has also not been proven to be an effective treatment for ALS.
Complications of ALS include:
- bed sores
The typical life expectancy for a patient suffering from ALS is two to five years. Approximately 20 percent of patients live with ALS for over five years. 10 percent of patients live with the disease for over 10 years.
ALS is incurable. However, medication and supportive care can improve quality of life. Proper care can help you live happily and comfortably for as long as possible.
The most common cause of death from ALS is respiratory failure.