Amyotrophic Lateral Sclerosis (ALS)
What is amyotrophic lateral sclerosis (ALS)?
Amyotrophic lateral sclerosis (ALS), sometimes called Lou Gehrig's Disease, is a progressive brain disease that attacks the nerve cells (neurons) that control voluntary muscles. This disease belongs to a group of motor neuron disorders (e.g., muscular dystrophy, multiple sclerosis, Parkinson's disease) that lead to the gradual degeneration and death of motor neurons, the nerve cells located in the brain, brainstem, and spinal cord. These motor neurons serve as connections from the nervous system to the muscles in the body.
Imagine wanting to brush your teeth. The motor neurons in the brain (upper motor neurons) have to send a message to the motor neurons in the spinal cord (lower motor neurons). The lower motor neurons then send the message to the muscles that are needed to brush your teeth (arms, mouth, etc.). ALS causes both the upper and lower motor neurons to degenerate or die. Both the brain and spinal cord lose the ability to initiate and send messages to the muscles in the body. The muscles, which are unable to function, gradually atrophy (waste away) and fasciculate (twitch).
ALS does not impair a person's mind. It affects only the motor neurons. Personality, intelligence, memory, and self-awareness remain the same. The senses of sight, smell, touch, hearing, and taste remain intact as well.
What are some signs or symptoms of ALS?
ALS first affects an individual's ability to speak loudly and clearly. Eventually, it completely prevents speaking and vocalizing. Some of the earliest speech-related symptoms of ALS may include:
- nasal speech quality (talking out of your nose)
- difficulty pronouncing words due to weak, tight, or stiff speech muscles (dysarthria)
- difficulty with lengthy sentences or conversation
As muscles for breathing weaken, it becomes more difficult for patients to speak loud enough to be understood. Eventually extensive muscle atrophy eliminates one's ability to vocalize and speak altogether.
Patients may also experience difficulty chewing and swallowing. Initially only some food consistencies are affected, but over time it becomes difficult for the patient to swallow even pureed foods and saliva. People with ALS get tired easily and they may not have the energy to eat an entire meal. All of these factors make it difficult to maintain adequate nutrition and weight. Eventually doctors may decide that it is best to insert a feeding tube into the person's stomach to make sure they receive enough nutrition.
In some cases, initial symptoms affect only one leg or arm. Patients may have awkwardness and stumbling when walking or running. They may have difficulty lifting objects or with tasks that require manual dexterity (e.g., buttoning a shirt, tying a shoe, turning a key). Eventually the individual will not be able to stand or walk, get in and out of bed without help, or use hands and arms to perform activities of daily living, such as washing and dressing.
How is ALS diagnosed?
There is no specific laboratory test for ALS, making it hard to diagnose. The diagnosis is made using clinical findings in conjunction with results of electrodiagnostic studies and the absence of evidence of other disorders. According to the diagnostic guidelines of the World Federation of Neurology, there must be lower motor neuron degeneration detected by clinical electrophysiological or neuropathologic examination, signs of upper motor neuron degeneration by clinical examination, and progressive spread of signs within a region of the body or to other regions.
What treatments are available for people with ALS?
Presently, there is no cure for ALS. However, as more and more research is done on brain diseases, doctors are learning more about what causes ALS and how to best treat it. This has led to the development of medications to treat ALS. Riluzole, an antiglutamate agent, is the first FDA-approved drug for the treatment of patients with ALS. Although Riluzole is not a cure, results of clinical trials indicate some promise in prolonging life, especially with bulbar patients. The current trend is to evaluate potential additive or synergistic effects of drug combinations (how well two or more drugs may work better than one alone).
As with any incurable disease, the state of the art in treatment for ALS is symptom management (also referred to as palliative care). According to the World Health Organization, palliative care is active care of the total patient. Individuals with ALS receive the best treatment from multidisciplinary clinical teams that specialize in neuromuscular disorders. Intervention deals with symptoms that occur over the course of the disease process. The ALS Association and the Muscular Dystrophy Association sponsor clinics in many U.S.cities (information can be obtained from their websites—see list below).
What other organizations have information about ALS?
This list is not exhaustive, and inclusion does not imply endorsement of the organization or the content of the website by ASHA.
The following websites can provide information and support for people with ALS and their families:
What causes ALS?
The vast majority of ALS cases diagnosed in the United States each year (90%-95%) are not associated with genetic inheritance. Results of worldwide epidemiological research examining the population-based risk factors for ALS suggest increasing incidence. There are some links with ALS to occupations involving heavy labor, exposure to heavy metals, or a history of traumatic injury. With the exception of an unusually high frequency of cases occurring in specific regions of the western Pacific, particularly Guam, there is no pattern of geographic clustering of ALS. Nor is ALS associated with a particular race or educational level.
How common is ALS?
Information about the incidence and prevalence of amyotrophic lateral sclerosis is available in the ASHA report Incidence and Prevalence of Speech, Voice, and Language Disorders in Adults in the United States.