ALS (Amyotrophic Lateral Sclerosis): causes, symptoms and treatment - medical - 2023



Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease in which there is a progressive destruction of neurons, which ends up causing muscle paralysis and causing the person to die from the inability to breathe and maintain other vital functions.

It is a rare disorder that affects about 5 people out of 100,000 and that to this day continues without a cure, because the research is complicated, among other things, because we still do not understand well what its cause is.

ALS became world famous when Stephen Hawking, one of the great scientific minds of our time, was diagnosed with this disease.

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In today's article we will summarize everything that is known about this serious and unknown disease which continues to be a sentence for those affected.

What is ALS?

ALS is one of neurological diseases, that is, all those disorders that affect the functionality of the nervous system. In this case, ALS is a disease in which there is damage to neurons in the brain, brainstem, and spinal cord, which are responsible for transmitting nerve impulses to muscles throughout the body.

These nerve impulses are the body's way of transmitting information, so the neurons act as a kind of messengers. A person affected by ALS, due to causes that remain a mystery, will suffer a slow but progressive degeneration of these.

This neuronal damage will make the nervous system increasingly difficult to transmit information to the muscles of the body. The slow neurodegeneration explains why the disease manifests itself initially with muscle paralysis that becomes severe over time.

By not being able to stop the development of ALS, it is a deadly disease that ends up causing the death of the person when the paralysis reaches the muscles of the vital organs, since they do not receive nerve impulses from the neurons and end up not responding .

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The causes remain the biggest obstacle to advancing research on this disease. Since the reason why ALS develops is not known, in most cases, it is very difficult to find treatments that stop neurological deterioration.

Although it is known that the hereditary factor is important, since 1 in 10 people with ALS suffer from the disease due to genetic inheritance, the other 9 cases are of unknown cause.

It is not yet known what causes this neuronal damage. Researchers believe that it is due to an extremely complex interaction of genetic and environmental factors, although the exact relationship between them is not clear, so the priority in the investigation is to discover it.

However, it is known that, in addition to the hereditary component of the disease, there are other risk factors. Among them, age, since the risk of expressing the disorder is greater between 40 and 60 years. The disease was already "inside" the affected person, but symptoms usually appear in this age group.

What's more, ALS has been found to be slightly more common in men than women, although it is not entirely clear if the difference is enough to affirm that the male sex is a risk factor.

The genetics of the person themselves are also important. Do not confuse with genetic inheritance, because here we talk about cases that appear without having a family history. Most likely, there are certain genetic errors that appear randomly and that can predispose the person to suffer from the disease.

Smoking, exposure to environmental toxins or chemicals and even certain viral infections are hypothetical risk factors that continue to be investigated, although at the moment it cannot be said that they are related to the development of ALS.


The slow degeneration and subsequent death of neurons is responsible for the symptoms of this deadly disease. However, it must be borne in mind that, despite what it may seem, except in very specific cases, ALS is not responsible for a loss of mental capacity.

Cases of dementia are occasional, since most clinical signs are related to the difficulty (or, in final stages, inability) that the nervous system has to communicate with the muscles of the body.

The disease usually manifests itself from the age of 40, peaking in the 50s. However, it is possible that it appears in people younger or even older than 65 who had never had signs of ALS.

In the early stages, the disease has symptoms typical of the first signs of neuronal degeneration. Over time, this symptomatology progressively worsens until it is responsible, already in advanced stages, for the death of the person.

1. In early stages

The first symptom of the disease, which appears, as we have said, from the age of 40, it is muscle weakness, which usually begins in the arms, hands and legs, although it is possible that already from the beginning it affects the muscles involved in swallowing and speaking.

Therefore, the most common signs of ALS in early stages are as follows:

  • Dificulty to walk
  • Difficulty climbing stairs
  • Problems lifting weights
  • Changes in voice
  • Hoarseness
  • Frequent trips and falls
  • Muscle cramps
  • Spasms in the extremities
  • Trouble performing normal daily tasks
  • Difficulty speaking
  • Slight breathing difficulties

It must be borne in mind that these symptoms gradually worsen and that, in specific cases, other signs must be added: weight loss, muscle contractions, depression, behavioral changes, muscle stiffness ... Although these symptoms are not as frequent as the previous ones .

2. In advanced stages

Although symptoms start in the extremities, over time, in addition to worsening symptoms in these regions, neuronal damage spreads to other muscles, such as those of the thorax, which are linked to vital functions such as breathing.

It is at this time that the disease becomes serious and, in addition to putting the person's life at risk, greatly limits their quality of life, since they partially or totally lose their autonomy.

It is important to note that even in advanced stages, ALS does not affect the senses, that is, the affected person does not have problems with sight, hearing, touch, taste or smell. And, with the exception of specific cases, intellectual capacities remain intact. In other words, ALS affects "only" the muscles.

The problem is that the muscle weakness becomes such that it is not only that the person loses the ability to move, but the muscles responsible for ensuring the functioning of the vital organs also stop responding.

Therefore, in advanced stages, appearing after several years of the first symptoms, the signs of the disease are as follows:

2.1. Respiratory problems

The muscles responsible for breathing also become paralyzed, leading to constant suffocation and ultimately death from respiratory failure. In fact, it is the most frequent cause of death among those affected.

2.2. Motor disability

The affected person almost completely loses the ability to voluntarily move the muscles, thus ending up with complete motor paralysis. That is why people with ALS end up in a wheelchair.

2.3. Inability to speak

Unable to move the muscles, the person cannot speak either, so he relies on complex technologies to communicate.

2.4. Malnutrition and dehydration

Due to paralysis of the muscles involved in swallowing, feeding problems are common. The only way to fix it is by using a probe. In addition, when they can still swallow food, there is a greater risk of it entering the lungs, thus increasing respiratory problems.


ALS has no cure, which is why it remains a deadly disease to this day. In any case, despite not being able to heal and the damage caused by neuronal degeneration being irreversible, we do have some therapies that improve the prognosis of those affected.

Therefore, the treatment of ALS consists of, on the one hand, providing the person with all the necessary means and resources they need to feel comfortable and, on the other hand, administering therapies focused not on curing the disease or reversing its effects, but rather to slow down the progression of neurodegeneration, to postpone the appearance of the most serious symptoms, alleviate the effects of the disorder and ensure that the person maintains autonomy and quality of life for as long as possible.

As with all other neurological diseases, finding a cure for them is impossible today. Therapies are focused on reducing the damage caused by the disorder. Still, research continues and increasingly promising results are being obtained to discover new ways to treat ALS.

Today, treatment consists of a combination of drugs and assistive therapies.

1. Drugs

Rilutek and Radicava are two medications administered orally and intravenously, respectively, which, despite having side effects (headache, bruising, dizziness, kidney disorders, gastrointestinal problems ...), help to slow down the progress of the disease and, in the absence of more studies, seem to increase the life expectancy of those affected.

2. Therapies

Physiotherapy sessions, speech therapies, nutritional advice, psychological support, breathing therapies ... All this helps those affected to maintain autonomy for as long as possible, ensuring that the disease does not diminish the mood so quickly and ensuring that they prolong your quality of life for as long as possible.

Bibliographic references

  • Quarracino, C., Rey, R.C., Rodríguez, G.E. (2014) "Amyotrophic lateral sclerosis (ALS): follow-up and treatment". Argentine Neurology.
  • Ministry of Health and Social Policy. (2009) "Guide for the care of amyotrophic lateral sclerosis (ALS) in Spain". Government of Spain.
  • Zapata Zapata, C.H., Franco Dáger, E., Solano Atehortúa, J.M., Ahunca Velásquez, L.F. (2016) "Amyotrophic lateral sclerosis: Update". Latreia.