ALS (Amyotrophic Lateral Sclerosis): Symptoms, Causes & Treatment

Updated in February 2024

ALS, or Amyotrophic lateral sclerosis, is a neurodegenerative disease that causes the destruction of motor neurons in the brain and spinal cord. It is associated with symptoms such as muscle weakness, joint stiffness, loss of motor coordination or difficulty breathing.

ALS is more common in men aged between 40 and 50, but it can also appear in women. Its cause is not completely known, but it appears to be related to genetic and environmental factors.

The treatment of ALS is guided by a neurologist using medications to relieve symptoms and prevent disease progression. Treatment also involves other modalities, such as physiotherapy, speech therapy, occupational therapy and psychotherapy.

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Common symptoms

The main symptoms of ALS are:

  • Muscle weakness or atrophy in an arm or leg
  • Muscle spasms, cramps, or tremors, especially in the hands and feet
  • Muscle rigidity
  • Loss of motor coordination in the hands or arms
  • Difficulty writing or lifting an object
  • Difficulty walking or frequent stumbling
  • Slurred or coarse speech, or difficulty speaking
  • Difficulty swallowing

Symptoms of ALS typically appear in the arms, hands, legs and feet over the course of a few days or weeks and worsen over time. They eventually affect both sides of the body.

As the disease progresses, respiratory muscles may also be affected, and cause difficulty breathing, chronic respiratory failure or even respiratory arrest.

ALS appears only in the motor neurons present in the brain and spinal cord, and, therefore, the person feels little to no pain. Instead, their mobility is highly affected.

Confirming a diagnosis

The diagnosis of ALS is confirmed by a neurologist, who will evaluate the patient's  symptoms, health history and family history. They will also perform a physical and neurological examination.

In addition, the doctor may order blood and urine tests, MRI, electroneuromyography, a nerve or muscle biopsy, or a lumbar puncture. These tests help your doctor to rule out other health conditions with similar symptoms, such as myasthenia gravis or multiple sclerosis, as well as confirm the diagnosis of ALS.

Possible causes

The causes of ALS are not yet fully known, but it is known that genetic and environmental factors can increase the risk of developing this disease.

The main factors that can increase the risk for ALS are:

  • Family history of ALS
  • Age, being more common after age 40
  • Gender, being more common in men
  • Smoking habit
  • Exposure to toxic substances such as lead

These factors can cause the progressive death of upper motor neurons that run from the brain to the spinal cord as well as lower motor neurons that run from the spinal cord to the muscles. This breakdown in neurons is what ultimately causes symptoms.

Treatment options

The treatment of ALS should be guided by a neurologist and is aimed reducing damage caused to neurons and delaying progression of the disease.

The main treatment options for ALS are:

1. Medications

Medications like riluzole, edaravone or taurursodiol + sodium phenylbutyrate may be prescribed by the doctor to help reduce the destruction of motor neurons. They prevent worsening of the disease and improve quality of life.

The doctor may prescribe medications depending on the symptoms presented, such as gabapentin, baclofen or tizanidine for muscle spasticity, or atropine or amitriptyline to reduce excessive saliva production.

2. Botox injections

Botox injections may be administered by a doctor to relieve muscle stiffness or to prevent excessive saliva production when medications are not effective or well tolerated.

3. Occupational therapy

Occupational therapy is a great option to increase quality of life in cases where it is difficult to move or perform simple daily activities, like eating or walking.

This is because, with occupational therapy sessions, the therapist helps the person to use auxiliary equipment, such as special cutlery, canes, crutches, orthoses or a wheelchair, which allows them to carry out everyday tasks.

4. Speech therapy

Speech therapy is indicated to help improve speech or communication skills, and also address difficulties eating or swallowing.

5. Physiotherapy

Physiotherapy for ALS consists of performing exercises that improve blood circulation, increase strength and promote muscle movement. It helps to delay the destruction of muscles caused by this disease.

Physiotherapy can be aimed at supporting breathing, speech and promoting independence in carrying out daily activities.

6. Respiratory support

Respiratory support may be indicated by the doctor to facilitate breathing and maintain adequate oxygen levels in the body. It is advised for cases of ALS in which the breathing muscles are severely affected. It involves the use of non-invasive mechanical ventilation, with the use of a mask connected to a a device

In cases where the person has severe respiratory failure, the doctor may recommend mechanical ventilation through a tracheostomy. 

7. Diet

It is also important that the treatment of ALS is guided by a registered dietitian, so that the diet is adapted according to the evolution of the disease.

This is because due to difficulty swallowing, eating can become difficult and the person can lose weight quickly and develop nutritional deficiencies.

Therefore, a diet that is high in calories and incorporates dietary supplements may be recommended by a registered dietitian.

If the person is unable to consume food orally, the doctor may recommend an enteral diet through the gastrostomy tube.

8. Psychotherapy

Psychotherapy may also be recommended and should be carried out by the psychologist in order to help the person develop tools to cope with emotions and changes in life.

Psychotherapy can help relieve anxiety or depression, which can be common in people with ALS.

In some cases, the psychiatrist may prescribe antidepressants or anxiolytics.

Is amyotrophic lateral sclerosis curable?

There is no cure for ALS, as it consists of a progressive degeneration of motor neurons. This breakdown is impossible to reverse.

However, there are treatments that help to prevent the disease from progressing and to improve quality of life.

What is the life expectancy of a person with ALS?

After amyotrophic lateral sclerosis is diagnosed, life expectancy ranges between 3 and 5 years.

However, this varies from person to person, depending on the treatments carried out and the progression of the disease. There are cases of people who have lived more than 50 years with the disease, as in the case of Stephen Hawking.