Amyotrophic Lateral Sclerosis (ALS): see what it is and symptoms


What is amyotrophic lateral sclerosis?

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease of unknown cause that affects motor neurons, responsible for voluntary movements. It is characterized by the progressive loss of muscle strength, which affects movement, speech and swallowing, causing paralysis.

It is a rare disease, which affects about 0.002% of the world population, and is part of a group of diseases called motor neuron diseases (MDN).

Motor neurons are responsible for voluntary movements, that is, those that are made by the individual’s own will. There are two types of motor neurons: the upper and the lower. In the brain, the upper motor neuron sends electrical impulses that travel to the lower motor neurons (located along the spinal cord). These impulses are carried to the muscles, which transform them into movements.

In ALS, these neurons are progressively degenerated, causing the person to lose the ability to perform voluntary movements over time. With that, the person loses the movement of the arms, legs and even the face, reaching the point of not being able to speak.

Only the muscles of voluntary contraction are affected and, therefore, the patient is able to maintain normal heart, bowel and bladder functions. The senses (touch, taste, smell, sight and hearing) are also unaffected and ALS patients usually do not have dementia or other cognitive difficulties.

The life expectancy of a patient with the disease is about 3 to 5 years, and the main causes of death among these patients are related to respiratory problems. It is more frequent in men over 40, but after 70 years it affects men and women with the same frequency.

Other names for the condition are Charcot’s disease, the doctor who first described it, or Lou Gehrig’s disease, due to the baseball player being diagnosed with ALS. Currently, the best known case is that of theoretical physicist, cosmologist and author Stephen Hawking, who died on March 14, 2018 (aged 76), and lived with the aid of devices to get around and communicate.


For some, ALS is considered a subtype of motor neuron disease (MND), not a disease in itself. However, others believe that it is a disease of its own and has the subtypes mentioned here. There are also those who argue that each of these same subtypes are, in fact, separate diseases.

The fact is that all types, regardless of whether they are subtypes or separate diseases, can progress to amyotrophic lateral sclerosis. Still, they are not considered to be stages of the disease because they are not always related to their full development.

The types are as follows:

  • Amyotrophic lateral sclerose;
  • Progressive muscle atrophy;
  • Progressive bulbar palsy;
  • Primary lateral sclerosis.

Amyotrophic lateral sclerose

This term is used for cases in which the two types of neurons (upper and lower) are degenerate. In general, the life expectancy of patients with amyotrophic lateral sclerosis is about 3 years after the first manifestations.

In this type, symptoms start at a specific location, the weakness gradually expands at that location and starts to spread to the rest of the body.

Progressive muscle atrophy

Corresponding to 10% of cases, progressive muscle atrophy is limited to lower motor neurons. This type is characterized by progressive weakness over the years, and is not very different from ALS.

Progressive bulbar palsy

In rare cases, the disease attacks the bulbar muscles, affecting the tongue and mouth. The patient has problems talking, chewing and swallowing, in addition to, in some cases, releasing excessive saliva (drool).

Due to the difficulty in swallowing, these patients may end up taking food or drink to the lungs, which causes choking and increases the chances of contracting pneumonia or other diseases of the respiratory tract.

In general, patients with this type end up developing a typical condition of ALS, because muscle dysfunction is caused by the degeneration of lower motor neurons.

Primary lateral sclerosis

In this type, only the upper motor neurons are affected. The progress of the disease is similar to that of ALS, but it develops more slowly and in many cases it is not even fatal. It is the lightest and rarest form of the disease.

Causes and risk factors

In most cases, the disease appears sporadically and the cause is not known. Neurons can die for various reasons, such as oxidation, mitochondrial dysfunction, apoptosis (natural cell death), problems in the movement of mitochondria, lipids, proteins , among others.

There are a few cases (about 5%) that have a genetic relationship, but there is not just one responsible gene, making it difficult to understand the causes of the disease.

Some risk factors being investigated are:

Genetic mutation

Some known genetic mutations can trigger ALS, bringing symptoms very similar to the sudden onset of the disease.


ALS usually affects people between 40 and 60 years of age. In rare cases, it can appear at age 20 or even during childhood.


Before age 65, the disease develops more frequently in men than in women. However, this difference between the sexes ceases to exist after the age of 70.


People with the disease usually have high levels of glutamate, a neurotransmitter very present in mammals, which acts on cognitive functions such as memory and learning. However, glutamate can be toxic to some neurons and also be responsible for the degeneration of motor neurons.


When an error occurs in the immune system and it starts attacking the body’s own normal cells, motor neurons can be targeted.

Incorrect protein consumption

Incorrect consumption by nerve cells can accumulate abnormal forms of proteins within the cells, causing them to be destroyed.


Smoking can cause changes in nucleic acids (DNA and RNA), which damages the production of proteins, enzymes, etc., which, in turn, can destroy neurons. This is the only proven external risk factor.

Studies show that smokers are twice as likely to develop ALS than people who have never smoked. Ex-smokers, on the other hand, have an intermediate risk.

Unconfirmed factors

There are some factors in common in several groups of ALS patients, but there is little evidence that they are responsible for triggering the disease. Some of them are exposure to pesticides and toxins, postmenopausal hormones and physical exercise, including sports.

In the United States, soldiers who fought in World War II in Korea, Vietnam and the Persian Gulf are believed to be more likely to develop the disease. Some reasons for this are exposure to heavy metals, toxins and intense physical effort.


In the beginning, the symptoms are usually very subtle and the patient needs to be aware of what he feels. Some primary symptoms are:

  • Muscle weakness;
  • Fasciculations (small involuntary momentary muscle contractions);
  • Cramps;
  • Muscular stiffness;
  • Speak badly;
  • Dysphagia.

The parts of the body that will experience the first symptoms depend on which muscles are the first to be affected. Some people begin to experience problems with their hands and arms, having difficulty performing simple tasks such as writing, opening a jar or zipping. Others may start with weakness in their legs, difficulty walking, start to stumble a lot and have frequent falls. There are also those who have the first symptoms in the mouth, tongue, pharynx, etc., causing problems in speech and difficulty in swallowing. Over time, patients may find it difficult to control crying and laughing.

The onset of the disease may be limbic or bulbar. It is called limbic when it starts in the arms and legs, and bulbar when the problem first appears in the mouth area. Regardless of where the disease starts, the weakness and atrophy spread to the rest of the body as the disease develops.

Depending on the neurons affected, the manifestation of symptoms may be slightly different. Symptoms related to degeneration of the upper motor neuron are spasticity (change in muscle stiffness) and exaggerated reflexes (hyperreflexia). The degeneration of the lower motor neurons, on the other hand, causes muscle weakness, atrophy, cramps and fasciculations.


There is no specific exam to diagnose ALS. The professionals trained to make the diagnosis are general practitioners and neurologists.

The doctor should require a large number of tests to make sure that the patient does not have other diseases with similar symptoms that can be easily confused. Some of these diseases are AIDS , polio , multiple sclerosis and spinal muscle amyotrophy. In addition, cramps and fasciculations can occur in benign situations, without necessarily indicating a specific condition.

In Brazil, the diagnosis takes, on average, 11 months. This is because it is a rare disease, which is poorly understood, and can be assimilated to others in the early stages. Since the prognosis of the disease is severe and there are many diseases that manifest in a similar way, it is common for the patient to seek a second neurological opinion.

The tests that should be done to diagnose ALS are:

Electromyography (EMG)

Using electrodes, a device measures the electrical activity of muscles when they contract and relax. Abnormalities in this activity can help the doctor to consider the possibility of ALS, as well as, if necessary, show if there is another muscle condition that may be causing the symptoms.

Nerve conduction study

This type of test is done to measure how well the nerves can send electrical signals from the spinal cord to the muscles. The test is done with an electrode that emits small shocks, positioned above the nerve, and another electrode in the corresponding muscle.

The electrode above the nerve emits small, brief shocks, while the other electrode records the time it takes the muscle to contract in response to the electrical pulse.

Magnetic resonance imaging (MRI)

MRI uses radio waves and a magnetic field to form detailed images of the brain and spinal cord. In the images, it is possible to identify if there are tumors, herniated discs or other conditions that may be causing the symptoms.

Urine and blood tests

Analysis of secretions and blood can help your doctor rule out the possibility of other illnesses.

Muscle biopsy

If the doctor suspects a muscle disease, a muscle biopsy may be required. A sample of the muscle is removed under local anesthesia and taken to the laboratory for analysis.

Lumbar puncture

This test is done to collect the cerebrospinal fluid (cerebrospinal fluid) for analysis. The fluid is found in the brain and spinal cord.

A specialist uses a small needle to collect the fluid between two spine vertebrae. The liquid is taken to the laboratory, where an analysis is made that may indicate a neurological condition.

Can amyotrophic lateral sclerosis cure? What is the treatment?

To this day, there is no known cure for ALS. However, there are treatments to improve the quality of life of patients, which must be administered by a multidisciplinary team including nurses, nutritionists, physiotherapists, social workers, among others.

Some measures that can help the patient’s quality of life are:


The use of a wheelchair, especially an electric one, ensures that the ALS wearer can move around independently. Manual wheelchairs may not be of much help, since, in general, the sick also lose their arm movements in a short time.


Physiotherapy improves independence and helps to postpone the need for mobility aids. Simple aerobic exercises such as walking, swimming and cycling (spinning) strengthen the unaffected muscles, in addition to improving cardiovascular health and contributing to the fight against fatigue and depression .

It is recommended that a physiotherapist set up an exercise and stretching schedule for the patient, as only the professional knows what is best for the patient and, thus, can prevent him from exercising harmful to his health. These exercises help against the appearance of spasticity and muscle shortening.

Speech Therapy

The monitoring of a speech therapist is important for the patient to maintain his communicative capacity. In the beginning, the doctor can help with speech, breathing and swallowing. However, over time, these skills will degenerate and it is up to the speech therapist to help the patient to communicate in other ways (with eyes, alphabets, etc.).

The doctor may also recommend devices such as speech synthesizers and other computer-based communication systems.

Occupational therapy

Occupational therapy helps the patient to rehabilitate, bringing solutions to the impediments caused by the disease. The therapist can help you find the right devices, adapt the home and spaces to the patient’s needs, as well as assist you in the use of new equipment and help you deal with your new day-to-day life.


A nutritionist can help the family prepare the patient’s meals. He can recommend specific foods to ensure that the patient has his daily absorption of calories, fibers and liquids, as well as avoiding foods that are difficult to swallow.

It is important to remember that ALS patients may experience frequent loss of appetite due to the disease. Therefore, sometimes the patient may not want to eat, which leads to malnutrition.

Percutaneous endoscopic gastrostomy

When the patient is no longer able to chew and swallow his food, it may be necessary to insert a feeding tube (called PEG) through percutaneous endoscopic gastronomy. Thus, the food is directed to the stomach, without the need for swallowing.

Noninvasive respiratory support

The use of continuous positive airway pressure devices (CPAPs) or positive airway pressure at two levels (BiPAPs) during the night helps in breathing, prevents apneas and death from respiratory arrest. This type of treatment is used when the person is still able to breathe during the day, but encounters difficulties at night.


People with respiratory failure must undergo a tracheostomy, surgery in which a hole is opened in the trachea, where a small tube is placed to assist the passage of air.

This surgical procedure is recommended for patients who cannot benefit from non-invasive respiratory support, either due to insufficiency or due to the accumulation of secretions that cannot be eliminated from the body correctly.

Medicines for ALS

Currently, there is only one drug used for ALS, called Riluzole , which works by inhibiting the action of glutamate on neurons. It is able to make the development of the disease a little slower, but the difference is only a few months.

The doctors in charge may prescribe some medications to relieve symptoms. It is important to note that some drugs are used because their adverse effects help to solve the problem, and not because they are indicated for this.

Below are listed some alternatives for each symptom:

Limb stiffness

  • Baclofeno;
  • Tizanidina.

Excessive salivation (drooling)

  • Amitriptilina;
  • Triexiphenidyl hydrochloride;
  • Scopolamine Butylbromide .

Thick secretions

  • Guaifenesina.

Depression and anxiety

  • Citalopram ;
  • Lorazepam.


  • Tramadol;
  • Trometamol Cetorolaco;
  • Morphine ;
  • Fentanyl .

Urinary incontinence

  • Tolterodina .

The use of medications should only be done under the indication and supervision of a qualified professional. The self-medication is not recommended as it can have serious side effects and put the patient’s life at risk.


NEVER self-medicate or stop using a medication without first consulting a doctor. Only he will be able to tell which medication, dosage and duration of treatment is the most suitable for his specific case. The information contained on this site is only intended to inform, not in any way intended to replace the guidance of a specialist or serve as a recommendation for any type of treatment. Always follow the instructions on the package insert and, if symptoms persist, seek medical or pharmaceutical advice.

Living together

Living with ALS is not easy, especially since, in addition to being limiting, it is a fatal disease. The change is not just for the patient, since the complications of the condition may require adaptations on the part of the whole family.

There may be a need to move home, school, college or workplace, in addition to implementing adaptive measures, such as, for example, wheelchair lifts on stairs. These adaptations must be seen with the help of an occupational therapist.

It is important to remember that the Biosafety Law (nº 11,105, of March 24, 2005) allows studies with embryonic stem cells in Brazil. Therefore, there is hope that in the future they can be used to treat degenerative diseases.

Some tips to improve living with the disease are:

For patients

Take time to think

The disease has a difficult nature to understand and knowing what will happen in the future can be very heavy. So it may be necessary for you to take time for yourself, to think, before telling family and friends.

Have hope

While some people cannot live long after the onset of the disease, there are many who manage to overcome more than 10 years. Believe in the interdisciplinary team, do the treatments correctly and stay positive.

Think beyond physical changes

Yes, the disease will take away many skills, but others will remain intact. Many people with ALS are able to live meaningful and joyful lives despite their physical limitations.

Join a support group

You are not alone. Meeting other people in the same condition can help you live better with the disease. Family and friends can benefit from exchanging ideas with other families. Identification with the other helps to endure psychological pain.

Plan your future

Don’t give up on your plans and dreams because of limitations. Finding solutions to carry out activities that give you pleasure is essential for a good quality of life. There are many adaptations that can be made and, depending on what you do, you can continue working and studying with the things you love. Always remember that you are not your disease. Join with your family, employers or teachers and medical staff to discuss adaptations.

For caregivers

Think about yourself

Being a caregiver takes a lot of time and attention, so that some people may forget to take care of themselves. Remember that you are also an individual who needs care and think about yourself, the things you need, the things you want and love to do. Taking time for yourself is not selfish and can help you be more willing to care for your loved one.

Ask for help

It is common for caregivers to end up suffering from psychological conditions. You need to be on the lookout for signs of depression and ask for help when needed. Visiting a psychologist and a psychiatrist is of utmost importance.

Don’t do everything yourself

Caring for a person is difficult and laborious, but you need to understand that you don’t have to do everything yourself. Ask for help from other family members and friends to do the shopping, take care of some household chores and even help with some of the patient’s needs.

Appreciate yourself

Always remember that the work you are doing is important and beautiful. Always keep in mind that it is a difficult job and that you are doing it very well. Value your skills.

Always seek to know more

Understand the disease, read articles, stay tuned for scientific news regarding amyotrophic lateral sclerosis. This can help you better plan for the future and prepare for the stages to come.

Don’t forget your role

Within a family, everyone has a role, be it mother, father, wife or child. When you become a caregiver, the dynamics of the relationship with the patient can change and, over time, can be forgotten. Always remember the relationship you used to have before your illness. Talk about the things you like, see photos of the family, get out of the routine together.

Participate in support programs

There are countries, states and even municipalities that have support programs for caregivers. Some of these programs offer financial support for the purchase of equipment. In Brazil, for example, there is free access to non-invasive home respirators and free distribution of Riluzole by SUS to ALS patients.


As the disease progresses, several complications can arise. Are they:

  • Breathing liquids and food (choking);
  • Respiratory failure;
  • Pneumonia;
  • Pressure ulcers;
  • Weight loss and malnutrition;
  • Cold;
  • Insanity.

Breathing liquids and food

It happens when the bulbar muscles are affected. In such cases, the food and drink may end up going to the wrong place and the patient starts to choke. To avoid this situation, you can have a treatment with a speech therapist or be fed through a tube.

Respiratory failure

Breathing itself is not affected. However, the process requires the help of some voluntary movement muscles and, therefore, the person may lose the ability to breathe without devices. This can lead to death from respiratory arrest, especially at night. To mitigate the chances, breathing apparatus can be used.


Aspiration of food and drink and weakening of the lung increase the chances of infections in the respiratory tract, including pneumonia.

Pressure ulcers

The pressure constantly exerted on the body by the wheelchair and bed forms lesions on the skin and on the underlying tissues called pressure ulcers (eschar). Prevention consists of keeping the skin dry, clean and hydrated, changing the patient’s position in the chair and / or bed frequently and observing the appearance of wounds and other skin lesions.

Weight loss and malnutrition

When unable to eat through swallowing, the patient can lose a lot of weight and reach the point of malnutrition. In these cases, tube feeding is indicated, which must be monitored by a nutritionist to ensure a balanced diet.


In some cases, there may be constipation, not because the intestine is unable to function properly, but because other muscles involved in the excretion process can be affected, such as the abdominal muscles.


In some rare cases, people with ALS can develop dementia. However, these cases are generally linked to the presence of other neurodegenerative diseases, such as Alzheimer’s disease.

Amyotrophic lateral sclerosis is poorly understood and there is still a long way to reach a cure. However, with treatment it is possible to lead a quality life.

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