Amyotrophic lateral sclerosis (Lou Gehrig's Disease, Charcot's Disease)

What is Amyotrophic lateral sclerosis?

This animation brought to you by Blausen Medical Communications.
Contact Andrew Walbank.

Amyotrophic lateral sclerosis (ALS) is a type of motor neuron disease that attacks the nerve cells (neurons) responsible for controlling voluntary muscles.Movement occurs when neurons in the brain (upper motor neurons) send messages to neurons in the spinal cord (lower motor neurons). The lower motor neurons relay these messages to the specific muscles that carry out the movement.ALS affects both upper and lower motor neurons. When these neurons degenerate or die, they cease to send messages to muscles. The muscles that lose functioning ability gradually weaken, waste away (atrophy), and twitch (fasciculations). Eventually, all voluntary movement is lost and the muscles become paralysed. Charcot made the first clinical description in the 1860s, hence the disease is named after him in Europe. In the US, the disease often is called Lou Gehrig disease after the baseball legend who died from ALS in 1941.

Statistics on Amyotrophic lateral sclerosis?

ALS is the most common type of adult-onset motor neuron disease. The number of cases in the United States is 20,000, and an estimated 5,000 cases are diagnosed each year. ALS occurs worldwide and is equally common in all races and ethnic background. The most common age when the disease is diagnosed is between 40 and 60 years, but younger and older people also can develop the disease. Men are affected more often than women, with a male to female ratio of 1.6:1.In the western Pacific (Guam, Papua New Guinea), new cases are increasingly diagnosed, where, in many cases, it is associated with Parkinsonism and dementia.

Risk Factors for Amyotrophic lateral sclerosis

Except for having a family member affected with the hereditary form of the disease, there are no known risk factors. 5-10% of cases of ALS are inherited, the remainder occur sporadically (with no apparent cause or association).

Progression of Amyotrophic lateral sclerosis

ALS causes progressive weakness and wasting of the muscles throughout the body. Initially, the muscles of the hands and feet may be affected; this gradually progresses to involve the more proximal muscles. Spontaneous tiny local areas of muscle twitching, called fasciculations, are characteristic in most patients.Onset of symptoms tends to be gradual. 70% of patients present initially with limb weakness, which may begin as a foot drop or problems with hand movements. Muscle pain beginning a few weeks before the weakness may also be a feature. When the chest muscles and diaphragm become too weak, the person is no longer able to breathe on his own. This is called respiratory failure and is by far the leading cause of death for people with ALS. Most people with ALS die within 5 years of the onset of symptoms. There is currently no cure for ALS and it tends to run a progressive course, leading ultimately to death from respiratory failure. Complications include lung infections, inability to perform activities of daily living, inability to walk and other complications from being wheelchair-bound such as pressure sores.

How is Amyotrophic lateral sclerosis Diagnosed?

Needle EMG and nerve conduction studies are the tests of choice for confirming the diagnosis of ALS. In ALS the EMG indicates that the motor nerves are not functioning, yet the sensory nerves are normal.

A CT or MRI scan of the head may be done to rule out other conditions.

If there is a family history, a genetic studies may be performed.

Prognosis of Amyotrophic lateral sclerosis

At present there is no treatment for ALS that significantly prolongs survival in and prognosis is poor. Death occurs within 3 to 5 years of diagnosis in most cases, but 25% of patients survive 5 years or longer. Some patients with familial ALS have been known to survive for longer up to 30 years after onset of ALS.

How is Amyotrophic lateral sclerosis Treated?

Currently there is no known cure for ALS so treatment is aimed at relieving symptoms and treating the complications that can occur. The treatment of ALS is also directed toward suppressing the immune inflammation which is felt to play a role in the degeneration of the nervous system of these patients.

A new medication called Riluzole may prolong life, but does not reverse or halt disease progression.

Baclofen or diazepam may be used to control spasticity that interferes with activities of daily living.

Trihexyphenidyl or amitriptyline may be prescribed for people with impaired ability to swallow saliva.

Physical therapy, rehabilitation, use of movement aids (such as braces or a wheelchair) or orthopedic intervention may be required to maximize remaining muscle function and general health.

Choking is common and there may be an early need for placement of a tube into the stomach for feeding (gastrostomy).

The use of devices to assist in breathing includes machines that are only used at night as well as mechanical ventilation. Patients should discuss their wishes regarding artificial ventilation with their doctors.

Emotional support is vital in coping with the disorder, because mental functioning is not affected. Groups such as the ALS Association may be available to assist in coping with the disorder.

Amyotrophic lateral sclerosis References

[1] Clem K, Morgenlander JC. Amyotrophic lateral sclerosis [online]. 2004 [cited 2005 Dec 29]. Available from: URL: http://www.emedicine.com/emerg/topic24.htm[2] Goldblatt D: Caring for patients with amyotrophic lateral sclerosis. In: Smith RA, ed. Handbook of Amyotrophic Lateral Sclerosis. Marcel Dekker; 1992. [3] Gourie-Devi M, Nalini A, Subbakrishna DK: Temporary amelioration of symptoms with intravenous cyclophosphamide in amyotrophic lateral sclerosis. J Neurol Sci 1997 Sep 10; 150(2): 167-72[4] Hankey G., Wardlaw J. Clinical Neurology. Demos Medical Publishing, United Kingdom, 2002. [5] Kasper DL et al, editors. Harrison's principles of internal medicine. 16th ed. New York; London: McGraw-Hill; 2005.[6] Mitsumoto H: Riluzole. What is its impact in our treatment and understanding of amyotrophic lateral sclerosis. Ann Pharmacother 1997; 31: 779-781.[7] Muscular Dystrophy Association: Facts About Amyotrophic Lateral Sclerosis (ALS) [online]. 2005 [cited 2005 Dec 29]. Available from: URL: http://www.mdausa.org/publications/fa-als.html[8] National Institute of Neurological Disorders and Stroke: Amyotrophic lateral sclerosis fact sheet [online]. 2005 [cited 2005 December 29th]. Available from: URL: http://www.ninds.nih.gov/disorders/amyotrophiclateralsclerosis/detail_amyotrophiclateralsclerosis.htm[9] Tandan R, Bradley WG: Amyotrophic lateral sclerosis: Part 1. Clinical features, pathology, and ethical issues in management. Ann Neurol 1985 Sep; 18(3): 271-80[10] Waragai M: MRI and clinical features in amyotrophic lateral sclerosis. Neuroradiology 1997; 39: 847-851