Amyotrophic Lateral Sclerosis
(ALS; Lou Gehrig's Disease; Motor Neuron Disease)
Definition
Amyotrophic lateral sclerosis (ALS) is a progressive nervous system disorder. It gradually destroys the nerves responsible for muscle movement. Over time, ALS leads to almost total paralysis of muscle movement, including breathing.
Prognosis is poor in most cases because of the progressive nature of the condition. Eventually, the disorder leads to respiratory failure. After diagnosis, life span ranges from 2 to 5 years. The five-year survival rate ranges from 14% to 25%. Up to 10% of patients will survive more than 10 years. In general, the younger the age of onset, the slower the disease progresses.
The Nervous System
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Causes
The cause of ALS is unknown. In a small number of cases, it appears that genes may play a role. Also, research has shown that there may be a reduced response to cell stress and cell toxicity. The reduced response may be due to a build-up of certain protein in the brain.
Risk Factors
A risk factor is something that increases your chance of getting a disease or condition. Risk factors include:
- Having a family member with ALS
- Being in the military or having other occupations with risk of exposure
- Having certain genetic mutations
Symptoms
Symptoms of ALS include:
- Progressive weakness in arms and legs (at first often on only one side) over weeks to months without changes in sensory abilities.
- Initial presentation may be a wrist or foot drop
- Trouble holding things without dropping them
- Frequent tripping while walking
- Shrunken muscles
- Twitchy muscles
- Unpredictable changing emotions
- Clumsiness
- Overactive reflexes
- Slurred speech
- Hoarseness
- Trouble chewing and swallowing, resulting in frequent choking and gagging
- Weight loss due to trouble eating
- Trouble breathing
- Excess salivation, drooling
- Mental skills and abilities remain unchanged in most
- Sensation is intact
- Trouble coughing, resulting in development of pneumonia
Diagnosis
The doctor will ask about your symptoms and medical history and perform a physical exam. There are no tests that definitively diagnose ALS.
Tests may be used to rule out other medical conditions. These tests may include:
- Electromyogram (EMG)/nerve conduction velocities (NCV)—To evaluate the muscles and the nerves
- Computed tomography (CT) Scan—A type of x-ray that uses a computer to make pictures of the structures inside the head and spine
- Magnetic Resonance Imaging (MRI) Scan—A test that uses magnetic waves to make pictures of the structures inside the head and spine
- Blood tests—To rule out metabolic, heavy metal exposure, or rarely infections (e.g., Lyme disease, HIV, human T-lymphotropic virus [HTLV])
- Lumbar puncture—A procedure to collect cerebrospinal fluid (CSF)
- Urine tests
Treatment
There is currently no cure for ALS.
Some treatment may help to reduce or manage symptoms for a time. For you and your family, a multidisciplinary approach may work best. This approach may include:
- Taking medicines
- Working with therapists and joining a support group
- Participating in religious and social activities
Treatment options include:
Medications
The drug riluzole has been approved for ALS. Clinical trials reveal a modest lengthening of survival. The drug may slightly improve functioning, but it does not stop the disease from progressing. Other drugs are also being studied.
Your doctor may prescribe these medicines for symptoms:
- Diazepam (e.g., Valium), baclofen (e.g., Lioresal), or dantrolene—To reduce spasticity
- Nonsteroidal anti-inflammatory drugs (NSAIDs) and other pain medicines
- Atropine (e.g., AtroPen), scopolamine (e.g., Isopto), botulinum toxin (e.g., Botox), antihistamine—To reduce heavy drooling
- Antidepressants and anti-anxiety medicines
- A combination of dextromethorphan and quinidine—To treat inappropriate laughter or crying
Other Types of Treatments
Supportive care may be needed as ALS progresses including:
- Physical therapy—To reduce pain associated with muscle cramping and spasticity.
- Respiratory care—In some cases, you may need to receive a mixture of air and oxygen from a machine. If you cannot move enough air in and out of your lungs, you may need surgery to have a tube inserted into your airway.
- Nutritional care—Your doctor may make changes to your diet. In some cases, getting nutrition through tube feeding is needed.
- Speech therapy—Speech therapy may be used to optimize communication. Therapy can include exploring alternative methods of communication.
RESOURCES:
ALS Association
http://www.alsa.org/
National Institute of Neurological Disorders and Stroke
http://www.ninds.nih.gov/
CANADIAN RESOURCES:
ALS Society of British Columbia
http://www.alsbc.ca/
ALS Society of Canada
http://www.als.ca/
REFERENCES:
Aggarwal, SP, Zinman L, Simpson E, et al. Clinical trial testing lithium in ALS terminates early for futility. Lancet Neurol. 2010; 9(5): 481-488.
Amyotrophic lateral sclerosis. EBSCO DynaMed website. Available at: https://dynamed.ebscohost.com/. Updated January 11, 2012. Accessed September 8, 2012.
Amyotrophic lateral sclerosis fact sheet. National Institute of Neurological Disorders and Stroke website. Available at: http://www.ninds.n.... Accessed September 8, 2012.
Bradley WG, Daroff RB. Neurology In Clinical Practice. Philadelphia, PA: Butterworth Heinemann Publishing; 2004.
Kasper DL, Braunwald E, Fauci AS, et al. Harrison's Principles of Internal Medicine. 16th ed. New York, NY: The McGraw-Hill Companies; 2005.
Miller RG, Mitchell JD, Lyon M, et al. Riluzole for amyotrophic lateral sclerosis (ALS)/motor neuron disease (MND). The Cochrane Library. Chichester, England: John Wiley & Sons, Ltd; 2005.
Samuels MA, Feske SK. Office Practice of Neurology. Philadelphia, PA: Churchill Livingstone; 2003.
Sathasivam S. Managing patients with amyotrophic lateral sclerosis. Eur J Intern Med. 2009;24:355-358.
Walling AD. Amyotrophic lateral sclerosis: Lou Gehrig's disease. Am Fam Physician. 1999;59:1489-1496.
4/17/2008 DynaMed Systematic Literature Surveillance https://dynamed.ebscohost.com/about/about-us: Fornai F, Longone P, Cafaro L, et al. Lithium delays progression of amyotrophic lateral sclerosis. Proc Natl Acad Sci USA. 2008;105:2052-2057.
1/14/2011 DynaMed's Systematic Literature Surveillance https://dynamed.ebscohost.com/about/about-us: Mateen FJ, Carone M, Sorenson EJ. Patients who survive 5 years or more with ALS in Olmsted County, 1925-2004. J Neurol Neurosurg Psychiatry. 2010;81(10):1144-1146.
Last reviewed October 2012 by Rimas Lukas, MD
Last Updated: 10/11/2012