amyotrophic lateral sclerosis


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Amyotrophic Lateral Sclerosis

 

Definition

Amyotrophic lateral sclerosis (ALS) is a disease that breaks down tissues in the nervous system (a neurodegenerative disease) of unknown cause that affects the nerves responsible for movement. It is also known as motor neuron disease and Lou Gehrig's disease, after the baseball player whose career it ended.

Description

ALS is a disease of the motor neurons, those nerve cells reaching from the brain to the spinal cord (upper motor neurons) and the spinal cord to the peripheral nerves (lower motor neurons) that control muscle movement. In ALS, for unknown reasons, these neurons die, leading to a progressive loss of the ability to move virtually any of the muscles in the body. ALS affects "voluntary" muscles, those controlled by conscious thought, such as the arm, leg, and trunk muscles. ALS, in and of itself, does not affect sensation, thought processes, the heart muscle, or the "smooth" muscle of the digestive system, bladder, and other internal organs. Most people with ALS retain function of their eye muscles as well. However, various forms of ALS may be associated with a loss of intellectual function (dementia) or sensory symptoms.
ALS progresses rapidly in most cases. It is fatal within three years for 50% of all people affected, and within five years for 80%. Ten percent of people with ALS live beyond eight years.

Causes and symptoms

Causes

The symptoms of ALS are caused by the death of motor neurons in the spinal cord and brain. Normally,
Amyotrophic lateral sclerosis (ALS) is caused by the degeneration and death of motor neurons in the spinal cord and brain. These neurons convey electrical messages from the brain to the muscles to stimulate movement in the arms, legs, trunk, neck, and head. As motor neurons degenerate, the muscles are weakened and cannot move as effectively, leading to muscle wasting.
Amyotrophic lateral sclerosis (ALS) is caused by the degeneration and death of motor neurons in the spinal cord and brain. These neurons convey electrical messages from the brain to the muscles to stimulate movement in the arms, legs, trunk, neck, and head. As motor neurons degenerate, the muscles are weakened and cannot move as effectively, leading to muscle wasting.
(Illustration by Electronic Illustrators Group.)
these neurons convey electrical messages from the brain to the muscles to stimulate movement in the arms, legs, trunk, neck, and head. As motor neurons die, the muscles they enervate cannot be moved as effectively, and weakness results. In addition, lack of stimulation leads to muscle wasting, or loss of bulk. Involvement of the upper motor neurons causes spasms and increased tone in the limbs, and abnormal reflexes. Involvement of the lower motor neurons causes muscle wasting and twitching (fasciculations).
Although many causes of motor neuron degeneration have been suggested for ALS, none has yet been proven responsible. Results of recent research have implicated toxic molecular fragments known as free radicals. Some evidence suggests that a cascade of events leads to excess free radical production inside motor neurons, leading to their death. Why free radicals should be produced in excess amounts is unclear, as is whether this excess is the cause or the effect of other degenerative processes. Additional agents within this toxic cascade may include excessive levels of a neurotransmitter known as glutamate, which may over-stimulate motor neurons, thereby increasing free-radical production, and a faulty detoxification enzyme known as SOD-1, for superoxide dismutase type 1. The actual pathway of destruction is not known, however, nor is the trigger for the rapid degeneration that marks ALS. Further research may show that other pathways are involved, perhaps ones even more important than this one. Autoimmune factors or premature aging may play some role, as could viral agents or environmental toxins.
Two major forms of ALS are known: familial and sporadic. Familial ALS accounts for about 10% of all ALS cases. As the name suggests, familial ALS is believed to be caused by the inheritance of one or more faulty genes. About 15% of families with this type of ALS have mutations in the gene for SOD-1. SOD-1 gene defects are dominant, meaning only one gene copy is needed to develop the disease. Therefore, a parent with the faulty gene has a 50% chance of passing the gene along to a child.
Sporadic ALS has no known cause. While many environmental toxins have been suggested as causes, to date no research has confirmed any of the candidates investigated, including aluminum and mercury and lead from dental fillings. As research progresses, it is likely that many cases of sporadic ALS will be shown to have a genetic basis as well.
A third type, called Western Pacific ALS, occurs in Guam and other Pacific islands. This form combines symptoms of both ALS and Parkinson's disease.

Symptoms

The earliest sign of ALS is most often weakness in the arms or legs, usually more pronounced on one side than the other at first. Loss of function is usually more rapid in the legs among people with familial ALS and in the arms among those with sporadic ALS. Leg weakness may first become apparent by an increased frequency of stumbling on uneven pavement, or an unexplained difficulty climbing stairs. Arm weakness may lead to difficulty grasping and holding a cup, for instance, or loss of dexterity in the fingers.
Less often, the earliest sign of ALS is weakness in the bulbar muscles, those muscles in the mouth and throat that control chewing, swallowing, and speaking. A person with bulbar weakness may become hoarse or tired after speaking at length, or speech may become slurred.
In addition to weakness, the other cardinal signs of ALS are muscle wasting and persistent twitching (fasciculation). These are usually seen after weakness becomes obvious. Fasciculation is quite common in people without the disease, and is virtually never the first sign of ALS.
While initial weakness may be limited to one region, ALS almost always progresses rapidly to involve virtually all the voluntary muscle groups in the body. Later symptoms include loss of the ability to walk, to use the arms and hands, to speak clearly or at all, to swallow, and to hold the head up. Weakness of the respiratory muscles makes breathing and coughing difficult, and poor swallowing control increases the likelihood of inhaling food or saliva (aspiration). Aspiration increases the likelihood of lung infection, which is often the cause of death. With a ventilator and scrupulous bronchial hygiene, a person with ALS may live much longer than the average, although weakness and wasting will continue to erode any remaining functional abilities. Most people with ALS continue to retain function of the extraocular muscles that move their eyes, allowing some communication to take place with simple blinks or through use of a computer-assisted device.

Key terms

Aspiration — Inhalation of food or liquids into the lungs.
Bulbar muscles — Muscles of the mouth and throat responsible for speech and swallowing.
Fasciculations — Involuntary twitching of muscles.
Motor neuron — A nerve cell that controls a muscle.
Riluzole (Rilutek) — The first drug approved in the United States for the treatment of ALS.
Voluntary muscle — A muscle under conscious control; contrasted with smooth muscle and heart muscle which are not under voluntary control.

Diagnosis

The diagnosis of ALS begins with a complete medical history and physical exam, plus a neurological examination to determine the distribution and extent of weakness. An electrical test of muscle function, called an electromyogram, or EMG, is an important part of the diagnostic process. Various other tests, including blood and urine tests, x rays, and CT scans, may be done to rule out other possible causes of the symptoms, such as tumors of the skull base or high cervical spinal cord, thyroid disease, spinal arthritis, lead poisoning, or severe vitamin deficiency. ALS is rarely misdiagnosed following a careful review of all these factors.

Treatment

There is no cure for ALS, and no treatment that can significantly alter its course. There are many things which can be done, however, to help maintain quality of life and to retain functional ability even in the face of progressive weakness.
As of the early 2000s, only one drug had been approved for treatment of ALS. Riluzole (Rilutek) appears to provide on average a three-month increase in life expectancy when taken regularly early in the disease, and shows a significant slowing of the loss of muscle strength. Riluzole acts by decreasing glutamate release from nerve terminals. Experimental trials of nerve growth factor have not demonstrated any benefit. No other drug or vitamin currently available has been shown to have any effect on the course of ALS.
A physical therapist works with an affected person and family to implement exercise and stretching programs to maintain strength and range of motion, and to promote general health. Swimming may be a good choice for people with ALS, as it provides a low-impact workout to most muscle groups. One result of chronic inactivity is contracture, or muscle shortening. Contractures limit a person's range of motion, and are often painful. Regular stretching can prevent contracture. Several drugs are available to reduce cramping, a common complaint in ALS.
An occupational therapist can help design solutions to movement and coordination problems, and provide advice on adaptive devices and home modifications.
Speech and swallowing difficulties can be minimized or delayed through training provided by a speech-language pathologist. This specialist can also provide advice on communication aids, including computer-assisted devices and simpler word boards.
Nutritional advice can be provided by a nutritionist. A person with ALS often needs softer foods to prevent jaw exhaustion or choking. Later in the disease, nutrition may be provided by a gastrostomy tube inserted into the stomach.
Mechanical ventilation may be used when breathing becomes too difficult. Modern mechanical ventilators are small and portable, allowing a person with ALS to maintain the maximum level of function and mobility. Ventilation may be administered through a mouth or nose piece, or through a tracheostomy tube. This tube is inserted through a small hole made in the windpipe. In addition to providing direct access to the airway, the tube also decreases the risk aspiration. While many people with rapidly progressing ALS choose not to use ventilators for lengthy periods, they are increasingly being used to prolong life for a short time.
The progressive nature of ALS means that most persons will eventually require full-time nursing care. This care is often provided by a spouse or other family member. While the skills involved are not difficult to learn, the physical and emotional burden of care can be overwhelming. Caregivers need to recognize and provide for their own needs as well as those of people with ALS, to prevent depression, burnout, and bitterness.
Throughout the disease, a support group can provide important psychological aid to affected persons and their caregivers as they come to terms with the losses ALS inflicts. Support groups are sponsored by both the ALS Society and the Muscular Dystrophy Association.

Alternative treatment

Given the grave prognosis and absence of traditional medical treatments, it is not surprising that a large number of alternative treatments have been tried for ALS. Two studies published in 1988 suggested that amino-acid therapies may provide some improvement for some people with ALS. While individual reports claim benefits for megavitamin therapy, herbal medicine, and removal of dental fillings, for instance, no evidence suggests that these offer any more than a brief psychological boost, often followed by a more severe letdown when it becomes apparent the disease has continued unabated. However, once the causes of ALS are better understood, alternative therapies may be more intensively studied. For example, if damage by free radicals turns out to be the root of most of the symptoms, antioxidant vitamins and supplements may be used more routinely to slow the progression of ALS. Or, if environmental toxins are implicated, alternative therapies with the goal of detoxifying the body may be of some use.

Prognosis

ALS usually progresses rapidly, and leads to death from respiratory infection within three to five years in most cases. The slowest disease progression is seen in those who are young and have their first symptoms in the limbs. About 10% of people with ALS live longer than eight years.

Prevention

There is no known way to prevent ALS or to alter its course.

Resources

Books

Feldman, Eva L. "Motor neuron diseases." In Cecil Textbook of Medicine, edited by Lee Goldman and J. Claude Bennett, 21st ed. Philadelphia: W.B. Saunders, 2000, pp. 2089-2092.

Periodicals

Ansevin CF. "Treatment of ALS with pleconaril." Neurology 56, no. 5 (2001): 691-692.
Eisen, A., and M. Weber. "The motor cortex and amyotrophiclateral sclerosis." Muscle and Nerve 24, no. 4 (2001): 564-573.
Gelanis DF. "Respiratory Failure or Impairment in Amyotrophic Lateral Sclerosis." Current treatment options in neurology 3, no. 2 (2001): 133-138.
Ludolph AC. "Treatment of amyotrophic lateral sclerosis-what is the next step?" Journal of Neurology 246, Supplement 6 (2000): 13-18.
Pasetti, C., and G. Zanini. "The physician-patient relationship inamyotrophic lateral sclerosis." Neurological Science 21, no. 5 (2000): 318-323.
Robberecht W. "Genetics of amyotrophic lateral sclerosis." Journal of Neurology 246, Supplement 6 (2000): 2-6.
Robbins, R.A., Z. Simmons, B.A. Bremer, S.M. Walsh, and S. Fischer. "Quality of life in ALS is maintained as physical function declines." Neurology 56, no. 4 (2001): 442-444.

Organizations

American Medical Association. 515 N. State Street, Chicago, IL 60610. (312) 464-5000. http://www.ama-assn.org/.
Muscular Dystrophy Association. 3300 East Sunrise Drive, Tucson AZ 85718-3208. (520) 529-2000 or (800) 572-1717. http://www.mdausa.org.

Other

ALS Society of Canada. http://www.als.ca/.
ALS Survival Guide. 〈http://www.lougehrigsdisease.net/〉.
American Academy of Family Physicians. http://www.aafp.org/afp/990315ap/1489.html.
National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/health_and_medical/disorders/amyotrophiclateralsclerosis_doc.htm.
National Library of Medicine. http://www.nlm.nih.gov/medlineplus/amyotrophiclateralsclerosis.html.
National Organization for Rare Diseases. http://www.stepstn.com/cgi-win/nord.exe?proc=Redirect&type=rdb_sum&id=57.htm.
World Federation of Neurology. http://www.wfnals.org/.

amyotrophic lateral sclerosis

 
a progressive neurologic disease characterized by degeneration of cell bodies of the lower motor neurons in the gray matter of the anterior horns of the spinal cord, some brainstem motor neurons, and the pyramidal tracts. Called also Lou Gehrig's disease.

The disease presents in adulthood, usually between the ages of 40 and 70, and affects men two to three times more often than women. The initial symptom is weakness of skeletal muscles, especially in the limb. As the disease progresses the patient has difficulty swallowing and talking, with dyspnea as the accessory muscles of respiration are affected. Eventually muscles atrophy and the patient becomes a functional quadriplegic. Mentation is not affected, so that the patient remains alert and aware of functional loss and the inevitable outcome. Although there may be periods of remission, the disease usually progresses rapidly, with death in 2 to 5 years. The cause of ALS is not known and there is no cure. Treatment is intended to provide symptomatic relief, prevent complications, and maintain optimal function as long as possible.
Patient Care. For the most part, ALS patients are cared for at home and are hospitalized only for diagnosis, when severe dysphagia demands an esophagostomy or gastrostomy for feeding, or when medical treatment is necessary for acute respiratory problems.

Intervention is planned and implemented according to each patient's needs at specific times during the course of the illness. In general, the major problems encountered are those related to (1) dysphagia and the need to meet nutritional requirements and avoid aspiration, (2) dyspnea and maintenance of blood gases within normal range, (3) aphasia and impaired verbal communication, (4) weakness, impaired mobility, and activity intolerance, (5) constipation, (6) pain and discomfort due to muscle cramps, and (7) alteration in self-concept and body image.

The patient and family also will need assistance in managing home care, coping with the effects of the illness, and maintaining optimal functioning in the patient. Community health nurses and home health care professionals and paraprofessionals should be available to provide a variety of services including physical therapy, occupational therapy, social services, mental health care, and medical and nursing care.

A resource agency that can provide assistance and information to ALS patients and their families is the Amyotrophic Lateral Sclerosis Association, 21021 Ventura Blvd., Suite 321, Woodland Hills, CA 91364-2206, (800) 782–4747; http://www.alsa.org.

a·my·o·tro·phic lat·er·al scle·ro·sis (ALS),

a fatal degenerative disease involving the corticobulbar, corticospinal, and spinal motor neurons, manifested by progressive weakness and wasting of muscles innervated by the affected neurons; fasciculations and cramps commonly occur. The disorder is 90-95% sporadic in nature (although a number of cases are inherited as an autosomal dominant trait [MIM*105400]), affects adults (typically, older adults), and usually is fatal within 2-5 years of onset. It is in the most common subgroup of motor neuron diseases, and the only one manifested by a combination of upper and lower abnormalities. Variants include: progressive bulbar palsy, in which isolated or predominant lower brainstem motor involvement occurs; primary lateral sclerosis, in which only upper motor neuron abnormalities are seen; and progressive spinal muscle atrophy, in which only lower motor neuron dysfunction is noted. See also entries under Henry Louis Gehrig

amyotrophic lateral sclerosis

(ā′mī-ə-trō′fĭk, -trŏf′ĭk, ā-mī′-)
n. Abbr. ALS
A chronic, progressive disease marked by gradual degeneration of the nerve cells in the spinal cord that control voluntary muscle movement, causing muscle weakness, atrophy, and eventual paralysis. Also called Lou Gehrig's disease.

amyotrophic lateral sclerosis (ALS)

[ā′mī·ōtrof′ik]
Etymology: Gk, a, mys + trophe, nourishment
a degenerative disease characterized by loss of the motor neurons, with progressive weakness and atrophy of the muscles of the hands, forearms, and legs, spreading to involve most of the body and face. It results from degeneration of the motor neurons of the anterior horns and corticospinal tracts, beginning in middle age and progressing rapidly, causing death within 2 to 5 years. Treatment is supportive and may involve a feeding tube or ventilator. There is no cure, but research is ongoing. Also called Lou Gehrig's disease, wasting palsy. See also Aran-Duchenne muscular atrophy.

amyotrophic lateral sclerosis

A chronic, progressive, degenerative, motor neurone disease, characterised by upper limb weakness, atrophy and focal neurologic signs.
Epidemiology Incidence 0.5–1.5/105, more common in men, usually >age 50; occurs randomly throughout the world with local clustering on the Kii Peninsula, Japan, and Guam, where it is associated with dementia, parkinsonism, and Alzheimer’s disease.
Clinical Loss of fine motor skills, triad of atrophic weakness of hands and forearms; leg spasticity; generalised hyperreflexia.
Management Possibly riluzole.
Terminal care Where allowed, one-fifth of all ALS patients choose to die by euthanasia.

amy·o·tro·phic lat·er·al scle·ro·sis

(ALS) (ā-mīō-trōfik latĕr-ăl skler-ōsis)
A disease of the motor tracts of the lateral columns and anterior horns of the spinal cord, causing progressive muscular atrophy, hyperactive deep tendon reflexes, fibrillary twitching, and spastic irritability of muscles; associated with a defect in superoxide dismutase.
Synonym(s): Aran-Duchenne disease, Charcot disease, Cruveilhier disease, Duchenne-Aran disease, Lou Gehrig disease, progressive muscular atrophy.

amyotrophic lateral sclerosis

A fatal condition of progressive degeneration of the motor tracts in the spinal cord, brainstem and motor cortex of the brain causing muscle atrophy and increasing weakness. Death usually occurs within five or six years of onset. Toxicity from glutamate, a NEUROTRANSMITTER, is thought to be a possible cause and antiglutamate drugs such as RILUZOLE (Rilutek) have been developed that appear to slow the progress of the disease. A form of motor neurone disease.

Gehrig,

Henry Louis, U.S. baseball player for the New York Yankees, 1903-1941, victim of Lou Gehrig disease.
Lou Gehrig disease - a disease of the motor tracts of the lateral columns and anterior horns of the spinal cord, causing progressive muscular atrophy. Synonym(s): amyotrophic lateral sclerosis; Aran-Duchenne disease; Aran-Duchenne dystrophy; Charcot disease; Cruveilhier disease; Cruveilhier palsy; Duchenne-Aran disease

amyotrophic lateral sclerosis

; ALS form of motor neurone disease characterized by progressive spastic limb paralysis due to corticospinal tracts deterioration, showing both upper and lower motor neurone lesion effects (see Table 1)
Table 1: Effects of damage to upper and lower motor neurones
Upper motor neurone lesionLower motor neurone lesion
ParalysisSpastic-type contractureFlaccid-type contractures may develop
Tendon reflexesExaggerated; hyperreflexiaReduced/absent; hyporeflexia
Plantar responseExtensor (Babinski's sign positive)Flexor (= normal; Babinski's sign negative)
Extraneous muscle activityNo fasciculations/fibrillationsFasciculations and fibrillations

amyotrophic lateral sclerosis (ā·mī··trō·fik laˑ·t·rl skl·rōˑ·sis),

n a fatal neurological condition in which the motor neurons in the anterior horns of the spinal cord and the corticospinal tracts degenerate, leading to weakness, muscle atrophy, and death, usually in 2 to 5 years. There is no known cure. Also called
Lou Gehrig's disease or
wasting palsy.

amy·o·tro·phic lat·er·al scle·ro·sis

(ALS) (ă-mīō-trōfik latĕr-ăl skler-ōsis)
Fatal degenerative disease involving the corticobulbar, corticospinal, and spinal motor neurons, generally manifested by progressive weakness and wasting of muscles innervated by the affected neurons. Sometimes called Lou Gehrig disease.
Synonym(s): motor neuron disease (1) .

amyotrophic lateral sclerosis (ALS) (ā´mīətrō´fik lat´ərəl sklərō´sis),

n a degenerative disease of the motor neurons, characterized by atrophy of the muscles of the hands, forearms, and legs, and spreading to involve most of the body. Colloquial term is Lou Gehrig's disease.

amyotrophic lateral sclerosis

a type of motor disorder of the nervous system in humans in which there is destruction of the anterior horn cells and pyramidal tract. The cause is unknown. It is characterized by weakness, spasticity and muscle atrophy and is fatal in most cases. One form of hereditary canine spinal muscular atrophy is similar to this disease.

Patient discussion about amyotrophic lateral sclerosis

Q. What are the presenting signs of ALS? Are the upper or lower extremeties affected initialilly?

A. The most common presenting sign of ALS is asymmetric limb weakness, usually starting with the hands (problems with pinching, writing, holding things etc.) shoulders (lifting arms above head etc.) or legs (problems walking).

Other presenting signs may be problems with speaking or swallowing, although these are less common.

You may read more here:
www.nlm.nih.gov/medlineplus/amyotrophiclateralsclerosis.html

Q. hola amigos como estan yo estranando al amor de mi via que es monica la amo mchoy la estrano bastante hola soy un tipo muy feliz ya encontre el amor de mi vida nos casamos en diciembre tenemos muchos suenos ,un camino muy largo que recorrer pienso entregarme por completo al amor y dedicarnos el uno para el hotro ,yon amo ami baby estoy muy enamorado ella lo sabe es mi baby te amo mi gatita bebe

A. ¿Cuál es la pregunta?

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References in periodicals archive ?
Occupational exposures and amyotrophic lateral sclerosis.
Geographic Landscape of Amyotrophic Lateral Sclerosis R&D Activities
Analysis of key recent licensing and partnership agreements in Amyotrophic Lateral Sclerosis Therapeutics market.
The otolaryngologic presentation of amyotrophic lateral sclerosis.
It also reviews key players involved in the therapeutic development for Amyotrophic Lateral Sclerosis and special features on late-stage and discontinued projects.
The analysts forecast the Global Amyotrophic Lateral Sclerosis Drugs Market to grow at a CAGR of 5.
Vitamin D deficiency and its supplementation in patients with amyotrophic lateral sclerosis.
Mutations in the FUS/ TLS gene on chromosome 16 cause familial amyotrophic lateral sclerosis.
Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's Disease or motor neuron disease, is a disease that causes progressive wasting of certain nerve cells of the brain and spinal column called motor neurons, which facilitate the movement of body parts.
This textbook on the assessment and management of respiratory concerns caused by amyotrophic lateral sclerosis has been designed for health care professionals and students who need to maintain a higher quality of life for patients with motor neuron diseases.
Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig's disease, is a progressive neurodegenerative disease that attacks the motor neurons of the brain and spinal cord that are responsible for voluntary muscle movement leading to degeneration of the voluntary motor system.
Tokyo, Japan, Nov 8, 2005 - (JCNN) - Hitachi announced on November 7 that its Ubiquitous Platform Systems Group has commercialized an improved version of Den-no-Shin, its proprietary device to facilitate communications for amyotrophic lateral sclerosis (ALS) patients.

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