Amyotrophic lateral sclerosis (ALS), also known as Motor Neuron Disease (MND), Lou Gehrig's Disease,
and Charcot's disease, is a progressive neurodegenerative disease which attacks motor neurons in the
brain and spinal cord resulting in the wasting away of muscle and loss of movement. There is an
estimated 30,000 people in the United States living with ALS at any given time and every 90
minutes, someone is diagnosed with the disease. Approximately ninety percent of all ALS cases are
sporadic, meaning there is no known history of the disease in a family. The remaining 10 percent
of cases are known as familial ALS.
ALS can affect anyone of any age, gender or race, however, for the most part ALS affects people between the ages of 40 and 70.
Some early signs and symptoms
of ALS include:
- muscle cramps and muscle twitching
- weakness in hands, legs, feet or ankles
- difficulty speaking or swallowing
The senses, including hearing, sight, smell, taste, and touch, are not affected by ALS. In most cases of ALS, cognitive function is not affected.
ALS is not experienced in the same way among all diagnosed, and the manner and speed at which the disease
moves throughout a person's body can vary greatly. Most people live about 3-5 years after they experience
their first signs of disease, with one in ten people surviving at least 10 years.
The variable rate of
disease progression makes prognosis
difficult to predict and therapies challenging to develop.
There are currently no known effective cures or treatments to stop disease progression of ALS. ALS is a complex
disease which varies from person to person and far more research is necessary to discover effective treatments
for each person living with ALS.
Researchers at the ALS Therapy Development Institute (ALS TDI) are working hard each day to change that. We aim
to do this by identifying, testing, and developing promising new treatments, such as AT-1501
, and by learning
more about the disease through our Precision Medicine Program
, the first and largest study of its kind in ALS.
Amyotrophic lateral sclerosis, ALS, is caused by progressive deterioration and death of motor neurons,
leading to muscle weakness and paralysis.
Ten percent of cases are known as familial ALS
where a specific genetic mutation is inherited and passed down
from generation to generation. Over 29 ALS-specific genetic mutations have been identified to date 
. The most
common known genetic mutation in ALS is the C9orf72 gene, which accounts for approximately 30 to 40 percent of
all familial ALS cases 
. Mutations in the SOD1 gene make up around 20 percent of familial ALS, and TARDBP
and FUS gene mutations each account for about 5 percent of familial cases.
The remaining 90 percent of cases are known as sporadic ALS
, meaning there is no known history of the disease
in a family. There are many theories outlining potential causes of ALS including oxidative stress, mitochondrial
dysfunction, immune system over activity, glutamate toxicity and toxic exposures. Studies have shown that those
who have served in the military are more likely to develop ALS than the general population 
. It is
important to note that clinically, familial ALS and sporadic ALS are seemingly indistinguishable from one another.
ALS can affect anyone of any age, gender or race.
However, for the most part, ALS affects people between the ages of 40 and 70
. ALS appears to affect men at a
higher rate than women below the ages of 65. Over the age of 70, incidence appears to be the same. According
to recent research, incidence of ALS appears to be greater in white populations than in African American,
Asian or Hispanic populations  
There is no single diagnostic tool for ALS.
The El Escorial criteria is commonly used to aid diagnosis, which requires the following:
- Evidence of lower motor neuron (LMN) degeneration by clinical, electrophysiological or neuropathologic examination.
- Evidence of upper motor neuron (UMN) degeneration by clinical examination.
- Progressive spread of symptoms or signs within a region or to other regions, as determined by history or examination.
However, these criteria are limited. A series of clinical procedures may also be conducted to rule out neurological
conditions whose symptoms closely resemble ALS. This means the ALS diagnostic process includes eliminating the
possibility of many other diseases along the way, including infections like Lyme disease and other neurological
disorders such as multifocal motor neuropathy, before making a final diagnosis. For this reason, diagnosis can
take as long as 12 to 14 months in some cases.
Throughout the diagnostic process, people might receive a diagnosis of suspected, possible, probable or definite
. These designations depend on which parts of the body are affected by the disease. Without a definite
people with possible or probable ALS nevertheless remain eligible
to participate in a growing number of clinical
trials evaluating emerging treatments for the disease. For a full list of ALS studies, visit our clinical trials
Some of the procedures a person may undergo on their way to an ALS diagnosis may include:
When a familial case of ALS
(fALS) is suspected, genetic testing might also be recommended. Commercially
available tests can identify dozens of ALS-linked genes. Those that undergo genetic testing are typically
provided genetic counseling, during which they learn how to interpret results.
Electromyography and nerve conduction studies
These tests enable clinicians to check whether motor nerves are plugged into the muscles and are working properly. Nerve
conduction studies (NCS) test whether the motor nerves can send signals of sufficient strength to enable movement of the
(EMG) tests measure the ability of these muscles in response to these signals to trigger
contraction. These tests help rule out certain disorders including those of the peripheral nerves.
Clinicians may also recommend a biopsy to further investigate affected muscles. Examination of muscle tissue under the
microscope can help rule out certain muscle diseases.
Magnetic Resonance Imaging (MRI)
MRI enables clinicians to examine organs and tissues including the brain and spinal cord. An MRI can help rule out a
number of conditions including brain tumors, multiple sclerosis
certain disorders of the spinal cord
These include blood and urine tests and spinal tap. However, researchers hope to expedite the diagnostic process by
developing tools that directly indicate whether a person has the disease.
A growing number of researchers suspect that MRI
could indicate whether a person has ALS rather than just
eliminate other diseases. Researchers hope certain biomarkers
can be used to identify people who are at
high risk of developing ALS before
they show symptoms.
Meanwhile, other scientists are developing a new method called electrical impedance myography (EIM) to diagnose ALS. This
test helps identify changes in affected muscles including atrophy. Scientists hope that this tool might also predict the
spread of ALS and aid in the development of treatments for the disease.
Most people with ALS live about 3-5 years after experiencing their first signs of the disease. At least one in
ten people live more than 10 years following their diagnosis. This variable rate of progression makes predicting
prognosis difficult. Clinicians instead rely on regular follow-up visits to monitor people with ALS to manage their disease.
Most people with ALS first feel muscle cramps, spasms
) in one of their arms or
legs. Other signs include weakness in the hands and feet or loss of balance. This form of the disease is
called limb-onset ALS.
About 25 percent of people with ALS first have trouble talking clearly and begin to slur their words. This form
of the disease is called bulbar-onset ALS.
After receiving a diagnosis
, people with ALS often schedule regular clinic visits every 3-4 months. During
these visits, patients are monitored for changes in their functional abilities. Commonly used tests for
monitoring ALS include:
ALS Functional Rating Scale-Revised (ALSFRS-R)
is a rating scale that measures changes in a person's abilities, including breathing, speaking,
sleeping, swallowing, and walking. The score is based on answers to 12 questions using a 48-point scale.
Individuals with ALS can track their disease at home using the ALSFRS-R scale, there are several websites
that offer that service free of charge, such as PatientsLikeMe
Precision Medicine Program (PMP)
Through the Precision Medicine Program
(PMP), researchers at ALS TDI partner with people with ALS around the
world to share and gather data on medical histories, family histories, genetics, biomarkers, and patient cell
biology to better understand the disease. Participants are provided with a secure online portal where their
data is located and easily accessible. They are able to track their own disease progression and follow how
various interventions impact their symptoms and progression.
Following clinic visits, individuals with ALS should consider asking for access to the “data” obtained during
the visit, such as the doctor's recorded ALSFRS-R and SVC or FVC scores. This information is used as enrollment
criteria for most clinical trials, and having it at hand can allow people to quickly determine if they
qualify for participation in a trial.
As the disease spreads, many muscles weaken and start to stiffen
. Range of motion exercises will likely be
recommended by physical therapists to help keep muscles loose and prevent the formation of contractures
and muscle pain.
A person with ALS's breathing may become affected
. A BiPAP machine or a phrenic pacer
might be suggested, particularly
to help improve sleeping. A feeding tube might be recommended to help meet nutritional needs. Medications might be
also recommended to help control pseudobulbar affect
(uncontrolled laughing or crying) or to help reduce muscle spasms.
People with bulbar-onset often work with a speech therapist to keep their ability to speak for longer. Those with
limb-onset ALS may rely on a cane, walker, or wheelchair due to difficulties walking and maintaining balance.
In most cases of ALS, cognitive function is not affected. However, over the past 10 years there has been an
increasing interest in investigating the overlap of ALS with Frontotemporal Dementia (FTD), another neurological
disease characterized by a decline in cognitive function. It is believed that up to a third of those diagnosed
with ALS may be affected by cognitive issues.
As the disease progresses and a person's muscles become paralyzed, they may lose the ability to move and
speak. Many people with ALS may require a wheelchair to get around and may communicate through assistive
devices like an eye-tracking device or a letter board. Some people with ALS choose invasive ventilation
by having a tracheostomy tube to help keep them breathing. People with late-stage ALS are often cared
for at home or in hospices.
There are currently no effective cures for ALS or treatments to stop disease progression
, but scientists
are working hard to develop therapies for this disease. There are currently only two treatments approved
by the FDA
in the United States. They are riluzole
(marketed as Rilutek or Tiglutik) and edaravone
(marketed as Radicava).
Much more is known about the use of riluzole
in ALS as it was approved in the 1990s. Its effects are modest, extending
life by about two to three months. In May 2017, edaravone
by the FDA. Clinical trials of edaravone
showed that those who began getting infusions of the medication early on
in their disease had the greatest potential to maintain muscle function. While neither of these treatments have been
shown to halt the progression of ALS, some people who take either or both of them may experience a positive impact on
are available today. People with ALS are encouraged to speak with their
doctor to determine if these treatments are right for them.
ALS is a complex, multi-system disease. A growing number of ALS clinics are deploying multidisciplinary teams to care
for and meet the physical, emotional, and nutritional needs of people with ALS. These palliative care teams include
physical, respiratory, speech, and occupational therapists to help people with ALS breathe easier, keep moving, and stay connected.
Today, there are dozens of potential treatments in clinical trial that are enrolling people with ALS and their families.
You can visit
our ALS Treatments and Drugs
page to read more about potential therapies for ALS. For more information on enrollment
and inclusion criteria for clinical trials, visit our clinical trials page