Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease that primarily affects nerve cells called motor neurons. Motor neurons allow the nervous system to communicate with muscles. Anytime a person performs a voluntary muscle movement—walk, talk, chew food, sign their name—motor neurons are firing.
Motor neurons reach from the brain to the spinal cord and from the spinal cord to the muscles throughout the body. The motor neurons located in the brain are called upper motor neurons. The motor neurons located in the spine are called lower motor neurons. ALS can affect both.
ALS destroys motor neurons. As a result, the brain is no longer to initiate or control voluntary muscle movements. A person loses the ability to use their muscles and as a result, the muscles atrophy.
Approximately 5,000 adults are diagnosed with ALS each year and about 30,000 Americans are living with the disease at any given time.
Here, we look at some other facts about ALS.
It’s also known as Lou Gehrig's Disease
ALS is also commonly known as Lou Gehrig's Disease, named in 1939 after the famed baseball player Lou Gehrig, who was diagnosed with the condition on his 36th birthday.
However, the first cases of the disease were described in 1869 by French neurologist Jean-Martin Charcot.
Early symptoms can be subtle
Early signs and symptoms can be subtle—a person may experience muscle cramps or stiffness, may be clumsy or trip when walking, or their muscles may feel more fatigued than usual. These signs and symptoms can easily be overlooked or dismissed, and do not seem significant until more severe signs and symptoms emerge.
Diagnosis can be challenging
The symptoms of ALS overlap with over neurological conditions, and there is no single test to diagnose ALS. This can make diagnosis a challenge, and the process involves ruling out other conditions that can cause symptoms. A number of tests may be ordered, including:
- Electromyography (EMG) and nerve conduction velocity (NCV)
- Blood and urine collection
- Spinal tap
- X-rays
- MRI
- Myelogram of cervical spine
- Muscle and/or nerve biopsy
- Thorough neurological examination
ALS is associated with a type of dementia
Traditionally, ALS was believed not to affect the parts of the brain associated with cognition—a person’s ability to think, remember, and reason.
However, more recent research has shown that ALS is associated with a type of dementia called frontotemporal dementia.
Dementia is a general term that describes the loss of cognitive ability. There are many different types of dementia. Frontotemporal dementia is a group of dementias that affect the frontal and temporal lobes of the brain.
Symptoms associated with frontotemporal dementia include changes in personality (such as inappropriate behavior), impaired judgement, difficulty regulating emotions, and problems with both using and understanding language.
ALS is increasingly being recognized as not only a disease that affects motor neurons, but a multisystem disorder that affects several areas of the central nervous system, including the brain.
Research is looking for new treatments
Currently, there's no cure for ALS and only a few available medications that can treat ALS. However, researchers are actively looking for new ways to treat the disease—and they are making progress. A major step occurred in 2017, when the first new ALS medication in 22 years was approved by the FDA.