What is Lou Gehrig''s Disease ?
From:Alslinks.com
Amyotrophic Lateral Sclerosis (ALS) is a progressive motor neuron disease identified by French neurologist Jean-Martin Charcot in 1869.
In the United States ALS is also known as Lou Gehrig's disease after the famous baseball star of the 1930's whose diagnosis brought a new awareness of the disease. In other parts of the world, in particular Europe, ALS is often called Motor Neuron Disease or MND.
ALS has a degenerative effect on the nerve cells of the spinal cord and the brain that control voluntary muscles throughout the body. Nerve cells are referred to as neurons and neurons that control muscle are called motor neurons. Motor neurons extend from the brain to the brain stem (upper motor neurons) and from the spinal cord directly to the muscle fiber (lower motor
neurons).
While lower motor neurons control muscle movement, upper motor neurons translate the required force and direction for smooth muscle movement (coordination).
Degeneration is a result of excess glutamate in the nervous system. It is uncertain if excess glutamate is being produced or if the transporters that keep glutamate in check are inadequate or if the glutamate receptors are defective. In any case, excess glutamate is toxic to nerve cells and results in cell death.
As the motor neurons degenerates and eventually dies, it is unable to transmit the electrical signal required for muscle movement. Because the muscle receives no input, it becomes weak and begins waste away (atrophy) and eventually becomes paralyzed.
ALS affects only the motor neurons of voluntary muscles. Voluntary muscles are all those that we control with our thought process such as limb movement, swallowing and breathing. (Breathing is not automatic as you can hold your breath and hence control your diaphragm muscles.)
Heart and digestive muscles are of a different type and not directly affected by ALS. Heartbeat and gastrointestinal tract functions perform automatically without our thought process and are controlled by involuntary muscles.
There are two variants of ALS. The most common is sporadic. The other is familial.
Sporadic ALS is random in the population with no know specific risk factors for cause of onset. From 3 to 8 people out of 100,000 worldwide develop ALS. From 5 to 10 percent of ALS cases are hereditary or familial. A specific genetic defect (mutation) of the enzyme known as superoxide dismutase 1 (SOD1) is know to cause about 20 percent of familial cases. Genetic mutations for all other familial cases have yet to be identified.
Families members of a ALS patient that have no family history of ALS are not believed to be at risk of developing the disease.
ALS symptoms may develop with either limb onset, bulbar onset or both.
With limb onset, the extremities and torso are affected. A general weakness of one or more legs, arms and hands and fatigue may be the first sign of the disease. Muscle cramping and fasciculation's (muscle twitching) will begin to develop. As the disease progresses, the patient may stumble while walking or loose grip of objects. Breathing may become labored. Uncontrolled crying and/or laughing (pseudobulbar affect) can occur.
Bulbar onset affects the face, mouth and throat muscles. With bulbar onset, one's voice may begin to weaken and become slurred. Chewing and swallowing becomes difficult (dysphagia). Fasciculation's will develop in the tongue.
Limb onset cases will eventually develop bulbar symptoms.
Although symptoms and the order in which they manifest themselves will vary for each individual, the eventual outcome of overall muscle weakness and paralysis is consistent. Sensory nerves of touch, sight, smell, taste and hearing are not affected by the disease. ALS does not impair the patients mind, intelligence or memory. But the pre-occupation of the diagnosis and occasionally depression may impact ones ability to concentrate and/or think clearly.
Diagnosing ALS is very difficult. A series of clinical test are required to rule out other diseases and ailments that have similar symptoms. A diagnosis of ALS is often a process of elimination, but tests like electromyography (EMG) that measures electrical response in the muscle fiber can show results typical for ALS.
Only one drug has been FDA approved for the treatment of ALS. Riluzole (Rilutek) is believed to reduce the amount of glutamate released to the motor neurons and increase life expectancy by several months.
ALS is incurable and fatal. In most cases, death occurs within 2 to 5 years after diagnosis but many have survived 10 to 20+ years. Respiratory complication is the primary cause of death for ALS patients.
Amyotrophic Lateral Sclerosis (ALS) is a progressive motor neuron disease identified by French neurologist Jean-Martin Charcot in 1869.
In the United States ALS is also known as Lou Gehrig's disease after the famous baseball star of the 1930's whose diagnosis brought a new awareness of the disease. In other parts of the world, in particular Europe, ALS is often called Motor Neuron Disease or MND.
ALS has a degenerative effect on the nerve cells of the spinal cord and the brain that control voluntary muscles throughout the body. Nerve cells are referred to as neurons and neurons that control muscle are called motor neurons. Motor neurons extend from the brain to the brain stem (upper motor neurons) and from the spinal cord directly to the muscle fiber (lower motor
neurons).
While lower motor neurons control muscle movement, upper motor neurons translate the required force and direction for smooth muscle movement (coordination).
Degeneration is a result of excess glutamate in the nervous system. It is uncertain if excess glutamate is being produced or if the transporters that keep glutamate in check are inadequate or if the glutamate receptors are defective. In any case, excess glutamate is toxic to nerve cells and results in cell death.
As the motor neurons degenerates and eventually dies, it is unable to transmit the electrical signal required for muscle movement. Because the muscle receives no input, it becomes weak and begins waste away (atrophy) and eventually becomes paralyzed.
ALS affects only the motor neurons of voluntary muscles. Voluntary muscles are all those that we control with our thought process such as limb movement, swallowing and breathing. (Breathing is not automatic as you can hold your breath and hence control your diaphragm muscles.)
Heart and digestive muscles are of a different type and not directly affected by ALS. Heartbeat and gastrointestinal tract functions perform automatically without our thought process and are controlled by involuntary muscles.
There are two variants of ALS. The most common is sporadic. The other is familial.
Sporadic ALS is random in the population with no know specific risk factors for cause of onset. From 3 to 8 people out of 100,000 worldwide develop ALS. From 5 to 10 percent of ALS cases are hereditary or familial. A specific genetic defect (mutation) of the enzyme known as superoxide dismutase 1 (SOD1) is know to cause about 20 percent of familial cases. Genetic mutations for all other familial cases have yet to be identified.
Families members of a ALS patient that have no family history of ALS are not believed to be at risk of developing the disease.
ALS symptoms may develop with either limb onset, bulbar onset or both.
With limb onset, the extremities and torso are affected. A general weakness of one or more legs, arms and hands and fatigue may be the first sign of the disease. Muscle cramping and fasciculation's (muscle twitching) will begin to develop. As the disease progresses, the patient may stumble while walking or loose grip of objects. Breathing may become labored. Uncontrolled crying and/or laughing (pseudobulbar affect) can occur.
Bulbar onset affects the face, mouth and throat muscles. With bulbar onset, one's voice may begin to weaken and become slurred. Chewing and swallowing becomes difficult (dysphagia). Fasciculation's will develop in the tongue.
Limb onset cases will eventually develop bulbar symptoms.
Although symptoms and the order in which they manifest themselves will vary for each individual, the eventual outcome of overall muscle weakness and paralysis is consistent. Sensory nerves of touch, sight, smell, taste and hearing are not affected by the disease. ALS does not impair the patients mind, intelligence or memory. But the pre-occupation of the diagnosis and occasionally depression may impact ones ability to concentrate and/or think clearly.
Diagnosing ALS is very difficult. A series of clinical test are required to rule out other diseases and ailments that have similar symptoms. A diagnosis of ALS is often a process of elimination, but tests like electromyography (EMG) that measures electrical response in the muscle fiber can show results typical for ALS.
Only one drug has been FDA approved for the treatment of ALS. Riluzole (Rilutek) is believed to reduce the amount of glutamate released to the motor neurons and increase life expectancy by several months.
ALS is incurable and fatal. In most cases, death occurs within 2 to 5 years after diagnosis but many have survived 10 to 20+ years. Respiratory complication is the primary cause of death for ALS patients.
posted by nikita | 7:33 PM
<< Home