Amyotrophic lateral sclerosis (ALS) is a rare neurological disease in which patients lose control of voluntary muscle movements, such as eating, speaking and walking.
As ALS is a progressive disease with no cure, patients will eventually die from the disease. However, the course of the disease is extremely variable from individual to individual. While some patients undergo fast progression of the disease, others experience slow progression. While many studies point to genetic factors that can explain this difference in variation, at this point, researchers still do not know why some individuals do better than others.
The majority of patients with ALS will develop the disease between the age of 40 and 70. The average age of diagnosis is 55.
As mentioned above, the course of the disease is very variable among individuals. Therefore, there is significant variability in how long people live. While the average life expectancy of an ALS patient is between 2-5 years from the time they are diagnosed, there is the example of Stephen Hawking, renowned theoretical physicist, who lived to the age of 76, which is 55 years after he was diagnosed.
In general, this is the statistical breakdown of life expectancy in patients with ALS:
- More than 50% of patients live longer than 3 years
- 20% of patients live for 5 years or longer
- 10% of patients live for 10 years or longer
- 5% live 20 years or longer (such as Stephen Hawking)
Causes of Death
The reason why patients with ALS die can vary. However, it is well known that most patients will die due to respiratory failure, which refers to the inability of patients to breathe. Patients with ALS develop respiratory failure due to the loss of nerve cells that control muscles that are responsible for breathing. Patients will die as they cannot get enough oxygen from the lungs to the rest of the body.
Failure to breathe properly also causes an inability to expel carbon dioxide from the blood. This happens in the late stages of ALS. When patients can’t get rid of the carbon dioxide in their blood, then high levels of carbon dioxide in the body cause loss of consciousness, leading patients to sleep for long periods of time. This can cause patients with ALS to die peacefully during their sleep.
Another potential reason why patients might die is the development of pneumonia, which is an infection in the lungs. As the disease progresses, patients start to lose control of their muscles that are responsible for swallowing food, liquids, and saliva, which causes these materials to go down the windpipe, instead of the throat. Often, food will carry along bacteria, which is what causes infection of the lungs.
As patients lose control of their swallowing muscles, this often leads to the development of malnutrition and dehydration, which is another reason why some people with ALS die.
Lastly, some patients with ALS will have a heart problem known as arrhythmia (which refers to irregular heartbeats). This can also play a role in death for some patients.
Things you can do
There are a number of things, such as medications and other types of therapies, that can help improve survival times of patients with ALS. These include medicines, noninvasive ventilation and use of feeding tube (percutaneous endoscopic gastronomy).
These are two drugs that are currently approved for the treatment of ALS:
- Riluzole (Rilutek) has been approved since 1995 for the treatment of ALS. Clinical trials have shown that use of riluzole leads to longer life expectancy for approximately 2-3 months. However, other studies have shown that there may be an even greater effect from use of riluzole.
- Edaravone (Radicava) is another approved treatment for ALS. It was approved in 2017 and was shown through clinical trials to reduce the decline in physical capabilities that patients with ALS experience.
- Other medicines that treat symptoms of the disease rather than the disease have also been shown to improve quality of life and prolong functional capabilities of patients.
Noninvasive ventilation refers to the use of ventilatory support (breathing support) without the use of an invasive artificial airway, such as endotracheal tube or tracheostomy tube. The primary way in which noninvasive ventilation works is through positive-pressure ventilation, which involves breathing through a mask that goes over the mouth and nose. Studies have shown that use of noninvasive ventilation prolongs survival between the ages of 7 to 11 months, depending on how often it is used and the patients themselves.
Percutaneous endoscopic gastronomy
Percutaneous endoscopic gastronomy refers to the installment of a feeding tube that is placed into the stomach and goes out of the body through the abdominal wall. While several studies show that use of a feeding tube does not lead to longer survival times, the American Academy of Neurology recommends that that use of a feeding tube is necessary for patients with ALS to keep their weight stable. However, doctors don’t all agree on when is the best time to install a feeding tube.
There is lots of research being conducted in the field of ALS and there are several advances that have been made in recent years to prolong the survival time of patients with ALS. Therefore, it is important to become educated in the latest research and keep up to date on the latest advances.