What is ALS?

What is ALS?

May is ALS Awareness Month, observed to raise awareness of and foster research for amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease.

In 2016 the Centers for Disease Control and Prevention estimated that between 14,000 – 15,000 Americans have ALS. ALS is a common neuromuscular disease worldwide. It affects people of all races and ethnic backgrounds.

What is ALS?

ALS, or amyotrophic lateral sclerosis, is a progressive neurodegenerative disease that affects nerve cells in the brain and the spinal cord. ALS impacts the voluntary muscle movement by affecting motor neurons in brain and spinal cord. It is a type of motor neuron disease that causes degeneration and death of motor neurons. (Motor neurons are nerve cells that extend from the brain to the spinal cord and to muscles throughout the body.)

A-myo-trophic comes from the Greek language “A” meaning “no” or “non”. “Myo” refers to muscle, and “trophic” means nourishment. A-myo-trophic, therefore, can be translated as “no muscle ” When a muscle has no nourishment, it atrophies, or wastes away. “Lateral” identifies the areas in a person’s spinal cord where portions of the nerve cells that signal and control the muscles are located. As this area degenerates, it leads to scarring or hardening (sclerosis) in the region.

The upper motor neuron (UMN) originates from the brain (mainly cerebral cortex or brain stem) and carries motor information down to the lower motor neurons. (The motor neurons initiate and provide vital communication links between the brain and the voluntary muscles.) The lower motor neurons (LMN) are located in the spinal cord or cranial nerve.  ALS affects both the upper and lower motor neurons.

Most people with ALS die from respiratory failure, usually within 3 to 5 years from when the symptoms first appear. However, about 10 percent of people with ALS survive for 10 or more years.

Clinical Signs:

The onset of ALS can be so subtle that the symptoms are overlooked, but gradually these symptoms develop into more obvious weakness or atrophy that may cause a physician to suspect ALS. Some of the early symptoms include:

  • fasciculation (muscle twitches) in the arm, leg, shoulder, or tongue
  • muscle cramps
  • tight and stiff muscles (spasticity)
  • muscle weakness in an arm, a leg, neck or diaphragm
  • slurred and nasal speech
  • difficulty chewing or swallowing

Usually, the first sign of ALS may appear as hand or arm weakness. A person will have more difficulty with fine motor coordination tasks like buttoning a shirt or writing in initial stages. Sometimes, symptoms initially affect one of the lower extremities, and people experience awkwardness when walking or running, or they notice that they are tripping or stumbling more often. As the disease progresses, an individual will have more difficulty with an inability to stand, walk, or to use his/her hands and arms.

Diagnosis of ALS:

It is difficult to diagnose ALS. There is no one test or procedure to ultimately establish the diagnosis. It is through a clinical examination and series of diagnostic tests, often ruling out other diseases that mimic ALS, that a true diagnosis can be established. A comprehensive diagnostic workup includes most, if not all, of the following procedures:

  • Electrodiagnostic tests including electomyography (EMG) and nerve conduction velocity (NCV)
  • Blood and urine studies including high resolution serum protein electrophoresis, thyroid and parathyroid hormone levels and 24-hour urine collection for heavy metals
  • Spinal tap
  • X-rays, including magnetic resonance imaging (MRI)
  • Myelogram of cervical spine
  • Muscle and/or nerve biopsy
  • A thorough neurological examination

Treatment Interventions:

Medical Management:

The U.S. Food and Drug Administration (FDA) has approved the drugs riluzole (Rilutek) and edaravone (Radicava) to treat ALS. Medications can also be prescribed to manage the symptoms including muscle cramps, stiffness, pain, depression, and sleep disturbances.

Nutritional support is important to provide enough calories, fluids, and avoiding foods that are difficult to swallow or chew. Respiratory support is needed for a patient who has difficulty breathing. Respiratory therapy is also required to manage secretions and to maintain proper oxygen level.


Physical, occupational and speech therapy can help to manage and limit clinical symptoms.

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This article was written by Bijal Shah, Clinical Educator

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