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ALS (Amyotrophic Lateral Sclerosis)

The ALS Program at Hospital for Special Surgery is an accredited ALS Certified Center of Excellence that provides in-person and telehealth care, treatment research and clinical trials for this debilitating and deadly neuromuscular disease. Learn more about ALS below.

What is ALS?

Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease or motor neuron disease, is a progressive, degenerative disease that destroys the nerve cells that control voluntary muscle movement. These cells, called "motor neurons," run from the brain through the brainstem or spinal cord to muscles that control movement in the arms, legs, chest, throat and mouth. In people with ALS, these cells die off, causing the muscle tissues to waste away. ALS does not affect a person's sensory functions or mental faculties. Other, nonmotor neurons, such as sensory neurons that bring information from sense organs to the brain, remain healthy.

Generally, ALS is categorized in one of two ways: Upper motor neuron disease affects nerves in the brain, while lower motor neuron disease affects nerves coming from the spinal cord or brainstem. In both cases, motor neurons are damaged and eventually die. ALS is fatal.

ALS life expectancy

The average life expectancy after diagnosis is two to five years, but some patients may live for years or even decades. Approximately 50% of people diagnosed with ALS live at least three or more years after receiving their diagnosis. About 25% live five years or more and up to 10% live more than 10 years. Some patients live much longer. The famous physicist Stephen Hawking, for example, lived for more than 50 years after he was diagnosed.

What are the symptoms of ALS?

Each person with ALS experiences a different proportion of upper and lower motor neurons that die. For this reason, the initial symptoms of ALS can vary considerably from person to person, as can the rate at which ALS progresses. Despite differences in symptoms or patterns of progression. However, all people with ALS will experience progressive muscle weakness and paralysis. The disease progresses, affecting more nerve cells as time goes on. As muscle tissue deteriorates, the muscles become weaker and atrophy (wither), and the person's limbs may begin to look thinner. However, the muscles can also become spastic (moving involuntarily) and this may lead to increased muscle tone in some parts of the body.

In the early stages of ALS, the symptoms may be so minor that they are overlooked. Common symptoms include:

  • Weakness in muscles of the hands, arms or legs.
  • Impairment in the use of arms and legs.
  • Twitching and cramping of muscles, especially those in the hands and feet.
  • Weakness in the muscles that control speech, swallowing or breathing.
  • Slow or slurred speech (called dysarthria or “thick speech”) and difficulty in projecting the voice.

In more advanced stages, ALS causes shortness of breath and difficulty in breathing and swallowing, which is what eventually lead to a person's death.

What causes ALS?

Although the cause of ALS is not completely understood, recent research suggests that multiple complex factors contribute to the death of motor neurons. Specific risk factors for ALS have not been conclusively identified, but ongoing research is exploring the possible role of genetics and/or environmental factors. Research published in 2009 suggests that smoking tobacco may heighten a person's risk for ALS.

Any one or more of the following factors may be responsible for the disease:

  • defective glutamate metabolism
  • free radical injury
  • mitochondrial dysfunction
  • gene defects
  • programmed cell death or apoptosis
  • cytoskeletal protein defects
  • autoimmune and inflammatory mechanisms
  • accumulation of protein aggregates (clumps)
  • viral infections

It is also likely that specific gene mutations and/or inherited traits modify the disease and increase one's likelihood of developing it.

Who gets ALS?

About 60% of the people reported to have ALS in the United States are men, and 93% of patients are Caucasian. Based on US population studies, a little more than 5,600 people in the US are diagnosed with ALS each year – approximately 15 new cases per day. It is estimated that as many as 30,000 Americans have the disease at any given time. Most people develop ALS between the ages of 40 and 70, with an average age of 55 at the time of diagnosis. However, rare cases of the disease do occur in people in their 20s and 30s.

How is ALS diagnosed?

Diagnosing ALS is difficult because there is no single medical test for it. Also, since many neurologic diseases cause similar symptoms, these other conditions must be ruled out first, through clinical examinations and medical tests. A comprehensive diagnostic workup includes most, if not all, of the following tests and procedures:

  • Electrodiagnostic tests including electomyography (EMG) and nerve conduction velocity (NCV), evaluating areas that are involved such as the bulbar region, (the head, neck and brain for speech and swallowing), as well as the cervical region (arms, diaphragm), thoracic region (muscles of breathing) and the lumbar region (legs).
  • Blood and urine studies, including high-resolution serum protein electrophoresis, thyroid and parathyroid hormone levels and 24-hour urine collection for heavy metals, in order to rule out any immunological or inflammatory disease.
  • Spinal tap.
  • X-rays and/or magnetic resonance imaging (MRI).
  • CT Scan of the cervical spine.
  • Muscle and/or nerve biopsy.
  • Thorough neurological examination.

Individual doctors will determine which of the above tests to conduct, usually based on the physical exam and the results of previous medical tests the patient has had.

Is there a cure for ALS?

Currently there is no known cure nor any treatment that can reverse the damage caused by ALS. There are some treatments, however, that have been shown to slow its progression.

What is the treatment for ALS?

ALS treatment currently focuses on medications that may slow the progression of the disease, along with providing care by multidisciplinary teams to assist patients and their families adjust to the many challenges of living with ALS. These teams of different specialists use devices and therapies to help patients manage symptoms and maintain their independence and quality of life. This multidisciplinary approach has also been shown to prolong the survival of people who have ALS.

ALS medications and clinical trials

The FDA-approved medications riluzole (brand names Rilutek, Teglutik) and edaravone (Radicava) have been shown to modestly slow the progression of ALS. In addition, there are several promising clinical trials being conducted worldwide that are yielding important information on how to combat this disease.

Assistive devices and therapeutics for daily living

Treatments and interventions to help people with ALS include:

  • proper body positioning
  • exercise regimens, physical and occupational therapy
  • devices and supports to help people walk
  • braces and splints for the legs and arms
  • customized wheelchairs
  • home assessment to make it easier to get around in the house
  • technological devices that help people communicate
  • suggestions for easier-to-swallow foods and liquids
  • support from a nutritionist
  • feeding tubes
  • diaphragm pacers
  • devices to help support breathing

Many people with ALS and other neuromuscular diseases decide to take part in research studies to help test new medications and treatments aimed at treating the disease. To learn more about these studies, visit the US National Institutes of Health Clinical Trials Registry and HSS ALS Program.

ALS (Amyotrophic Lateral Sclerosis) Patient Stories

In the news


  • Dean KE, Shen B, Askin G, Schweitzer AD, Shahbazi M, Wang Y, Lange D, Tsiouris AJ. A specific biomarker for amyotrophic lateral sclerosis: Quantitative susceptibility mapping. Clin Imaging. 2021 Jul;75:125-130. doi: 10.1016/j.clinimag.2020.12.018. Epub 2021 Jan 4. PMID: 33548870.
  • Shtilbans A, Choi SG, Fowkes ME, Khitrov G, Shahbazi M, Ting J, Zhang W, Sun Y, Sealfon SC, Lange DJ. Differential gene expression in patients with amyotrophic lateral sclerosis. Amyotroph Lateral Scler. 2011 Jul;12(4):250-6. doi: 10.3109/17482968.2011.560946. Epub 2011 Mar 4. PMID: 21375368.
  • Schweitzer AD, Liu T, Gupta A, Zheng K, Seedial S, Shtilbans A, Shahbazi M, Lange D, Wang Y, Tsiouris AJ. Quantitative susceptibility mapping of the motor cortex in amyotrophic lateral sclerosis and primary lateral sclerosis. AJR Am J Roentgenol. 2015 May;204(5):1086-92. doi: 10.2214/AJR.14.13459. PMID: 25905946; PMCID: PMC4889122.
  • Wainger BJ, Macklin EA, Vucic S, McIlduff CE, Paganoni S, Maragakis NJ, Bedlack R, Goyal NA, Rutkove SB, Lange DJ, Rivner MH, Goutman SA, Ladha SS, Mauricio EA, Baloh RH, Simmons Z, Pothier L, Kassis SB, La T, Hall M, Evora A, Klements D, Hurtado A, Pereira JD, Koh J, Celnik PA, Chaudhry V, Gable K, Juel VC, Phielipp N, Marei A, Rosenquist P, Meehan S, Oskarsson B, Lewis RA, Kaur D, Kiskinis E, Woolf CJ, Eggan K, Weiss MD, Berry JD, David WS, Davila-Perez P, Camprodon JA, Pascual-Leone A, Kiernan MC, Shefner JM, Atassi N, Cudkowicz ME. Effect of Ezogabine on Cortical and Spinal Motor Neuron Excitability in Amyotrophic Lateral Sclerosis: A Randomized Clinical Trial. JAMA Neurol. 2021 Feb 1.

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