Amyotrophic lateral sclerosis (ALS), often referred to as Lou Gehrig's disease or motor neuron disease, is a progressive, neurodegenerative disease that affects motor neurons. Motor neurons run from the brain through the brainstem or spinal cord to muscles that control movement in the arms, legs, chest, throat and mouth. Generally, motor neuron disease is categorized in one of two ways: Upper motor neuron disease affects nerves in the brain, while lower motor neuron disease affects nerves coming from the spinal cord or brainstem.
In ALS, both upper and lower motor neurons are damaged and eventually die. Each person with ALS has varying amounts of upper and lower motor neuron death, which results in a variety of symptoms. The disease progresses and gradually affects more nerve cells as time goes on. Muscle tissues waste away, or atrophy and the limbs begin to look thinner. The muscles become weaker and more spastic, or excess muscle tone may be seen. In ALS, motor neurons are the only kind of nerve cells that are affected. Other nerve cells, such as sensory neurons that bring information from sense organs to the brain, remain healthy.
Symptoms of very-early-stage ALS, which may be so minor that they are frequently overlooked, can include:
In more advanced stages, shortness of breath, difficulty in breathing and swallowing may occur.
The initial symptoms of ALS may vary considerably from person to person, as can the rate at which ALS progresses. Not all individuals with ALS develop the same symptoms or the same sequences or patterns of progression. However, progressive muscle weakness and paralysis are universally experienced.
Based on US population studies, a little more than 5,600 people in the United States are diagnosed with ALS each year – approximately 15 new cases per day. It is estimated that as many as 30,000 Americans have the disease at any given time.
According to the literature, 60% of the people reported to have ALS in the United States are men and 93% of patients are caucasian.
Most people who develop ALS are between the ages of 40 and 70, with an average age of 55 at the time of diagnosis. However, rare cases of the disease do occur in persons in their 20s and 30s. Approximately 50% of people diagnosed with ALS live at least three or more years after diagnosis. About 25% live five years or more and up to 10% live more than 10 years. Specific risk factors for ALS have not been conclusively identified, but ongoing research is exploring the possible role of genetics and/or environmental factors.
Although the cause of ALS is not completely understood, recent research suggests that multiple complex factors contribute to the death of motor neurons. Any one or more of the following factors may be responsible for the disease:
It is also likely that specific gene mutations and/or heredity modifies the disease and the likelihood of developing it.
Diagnosis of ALS is difficult, in part because there is no single test that confirms the presence of the disease. Moreover, since many neurologic diseases have symptoms that mimic those of ALS, it’s necessary to rule out these other conditions through a clinical examination and a series of diagnostic tests. A comprehensive diagnostic workup includes most, if not all, of the following tests and procedures:
The above tests are done at the discretion of the physician, usually based on the results of other diagnostic tests and the physical examination.
Currently there is no known cure or treatment that halts or reverses the progression of ALS. However, Riluzole and Radicava, both FDA-approved medications, have been shown to modestly slow the progression of ALS. In addition, there are several promising clinical trials being conducted worldwide that are yielding important information on how to combat this disease.
While the search for an effective treatment and cure continues, multidisciplinary teams across the globe are assisting patients and their families to adjust to the many challenges of living with ALS. These teams of specialists use devices and therapies to help manage ALS symptoms and allow people with the disease to maintain their independence and quality of life. This multidisciplinary approach has also been shown to prolong survival of people who have ALS.
Treatments and interventions may include:
Many people with ALS and other neuromuscular diseases decide to take part in research studies to help test new medications and treatments aimed at treating the disease. To learn more about these studies, visit the U.S. National Institutes of Health Clinical Trials Registry.
You can find more information on ALS at the following sites.