What is amyotrophic lateral sclerosis?
Amyotrophic lateral sclerosis (ALS) is a rare neurological disease that primarily affects the nerve cells (neurons) responsible for controlling voluntary muscle movement (those muscles we choose to move). Voluntary muscles produce movements like chewing, walking, and talking. The disease is progressive, meaning the symptoms get worse over time. Currently, there is no cure for ALS and no effective treatment to halt or reverse the progression of the disease.
ALS belongs to a wider group of disorders known as motor neuron diseases, which are caused by gradual deterioration (degeneration) and death of motor neurons. Motor neurons are nerve cells that extend from the brain to the spinal cord and to muscles throughout the body. As motor neurons degenerate, they stop sending messages to the muscles and the muscles gradually weaken, start to twitch, and waste away (atrophy). Eventually, the brain loses its ability to initiate and control voluntary movements.
ALS was once commonly known as Lou Gehrig’s disease, following the retirement of the famous ballplayer in the 1940s due to the disease.
What are the symptoms?
The onset of ALS can be so subtle that the symptoms are overlooked but gradually these symptoms develop into more obvious weakness or atrophy.
Early symptoms include:
- Muscle twitches in the arm, leg, shoulder, or tongue
- Muscle cramps
- Tight and stiff muscles (spasticity)
- Muscle weakness affecting an arm, a leg, the neck, or diaphragm
- Slurred and nasal speech
- Difficulty chewing or swallowing
The first sign of ALS usually appears in the hand or arm and can show as difficulty with simple tasks such as buttoning a shirt, writing, or turning a key in a lock. In other cases, symptoms initially affect one leg. People experience awkwardness when walking or running, or they may trip or stumble more often. When symptoms begin in the arms or legs, it is referred to as “limb onset” ALS, and when individuals first notice speech or swallowing problems, it is termed “bulbar onset” ALS.
As the disease progresses, muscle weakness and atrophy spread to other parts of the body. Individuals may develop problems with moving, swallowing (called dysphagia), speaking or forming words (dysarthria), and breathing (dyspnea). Although the sequence of emerging symptoms and the rate of disease progression can vary from person to person, eventually individuals will not be able to stand or walk, get in or out of bed on their own, or use their hands and arms.
Because people with ALS usually can perform higher mental processes such as reasoning, remembering, understanding, and problem solving, they are aware of their progressive loss of function and may become anxious and depressed. A small percentage of individuals may experience problems with language or decision-making, and there is growing evidence that some may even develop a form of dementia over time.
Individuals with ALS eventually lose the ability to breathe on their own and must depend on a ventilator. Affected individuals also face an increased risk of pneumonia during later stages of the disease. Besides muscle cramps that may cause discomfort, some individuals with ALS may develop painful neuropathy (nerve disease or damage).
Who gets ALS?
ALS is a common neuromuscular disease worldwide. It affects people of all races and ethnic backgrounds.
Risk factors for ALS include:
- Age. Although the disease can strike at any age, symptoms most commonly develop between the ages of 55 and 75.
- Gender. Men are slightly more likely than women to develop ALS. However, as people age the difference between men and women disappears.
- Race and ethnicity. Caucasians and non-Hispanics are most likely to develop the disease.
Sporadic ALS
Nearly all cases of ALS are considered sporadic. This means the disease seems to occur at random with no clearly associated risk factors and no family history of the disease. Although family members of people with sporadic ALS are at an increased risk for the disease, the overall risk is very low and most will not develop ALS.
Familial (Genetic) ALS
About 5 to 10 percent of all ALS cases are familial, which means that an individual inherits the disease from a parent. The familial form of ALS usually only requires one parent to carry the disease-causing gene. Mutations in more than a dozen genes have been found to cause familial ALS.
What causes ALS?
The cause of ALS is not known, and scientists do not yet know why ALS strikes some people and not others. However, scientific evidence suggests that both genetics and environment play a role in motor neuron degeneration and the development of ALS.
How is ALS diagnosed?
There is no single test that provides a definitive diagnosis of ALS. It is primarily diagnosed based on a detailed history of the symptoms observed by a physician during physical examination, along with a review of the individual’s full medical history and a series of tests to rule out other diseases. A neurologic examination at regular intervals can assess whether symptoms such as muscle weakness, muscle wasting, and spasticity are progressively getting worse. Some tests they might do would be an EMG, NCS, MRI, blood tests and muscle biopsy.
How is ALS treated?
There is no treatment to reverse damage to motor neurons or cure ALS. However, treatments can help control symptoms, prevent unnecessary complications, and make living with the disease easier.
Supportive health care is best provided by multidisciplinary teams of professionals such as physicians; pharmacists; physical, occupational, speech, and respiratory therapists; nutritionists; social workers; clinical psychologists; and home care and hospice nurses. These teams can design an individualized treatment plan and provide special equipment aimed at keeping people as mobile, comfortable, and independent as possible.
There are several FDA approved drugs that help treat ALS (but not cure).
- Riluzole (Rilutek) is an oral medication believed to reduce damage to motor neurons by decreasing levels of glutamate, which transports messages between nerve cells and motor neurons. Clinical trials in people with ALS showed that riluzole prolongs survival by a few months, particularly in the bulbar form of the disease. Individuals with swallowing difficulties may prefer the thickened liquid form (Tiglutik) or the tablet (Exservan) that dissolves on the tongue.
- Edaravone (Radicava) is given by intravenous infusion and has been shown to slow the decline in clinical assessment of daily functioning in persons with ALS.
- Relyvrio or previously known as AMX0035 (sodium phenylbutyrate and ursodoxicoltaurine) is an oral fixed-dose combination therapy that may reduce neuronal cell death in people living with ALS, either as a stand-alone therapy or when added to existing treatments.
Physicians can also prescribe medications to help manage symptoms of ALS, including muscle cramps, stiffness, excess saliva and phlegm, and the pseudobulbar affect (involuntary or uncontrollable episodes of crying and/or laughing, or other emotional displays). Drugs also are available to help individuals with pain, depression, sleep disturbances, and constipation.
**Information from https://www.ninds.nih.gov/amyotrophic-lateral-sclerosis-als-fact-sheet where you can find out more.