how-als-is-diagnosed

How ALS is diagnosed

There are different clinical challenges that can delay an ALS diagnosis. The average life expectancy of people with ALS is typically 2–5 years, but by shortening the time to diagnosis, people with ALS can receive earlier access to care that can lead to better health outcomes. 

Using the Airlie criteria
to diagnose ALS

The Airlie criteria is a tool that your healthcare provider can use to predict the degree of certainty of your diagnosis and to assess if you are eligible for clinical trials.

  • Clinically Definite ALS


    Defined by clinical or electrophysiological evidence, such as:

    • The presence of lower motor neuron symptoms and upper motor neuron symptoms in the bulbar region and in at least 2 spinal regions
    • The presence of lower motor neuron symptoms and upper motor neuron symptoms in 3 spinal regions
  • Clinically Probable ALS


    Defined by clinical or electrophysiological evidence of lower motor neuron symptoms and upper motor neuron symptoms in at least 2 regions with some upper motor neuron signs rostral to (or above) the lower motor neuron signs.

  • Probable ALS -
    Laboratory Supported


    Exists when clinical signs of upper motor neuron and lower motor neuron dysfunction are found in only 1 region, but electrophysiological signs of lower motor neuron are observed in at least 2 regions.

  • Clinically Possible ALS


    Defined by clinical or electrophysiological evidence, as follows:

    • The presence of upper motor neuron and lower motor neuron dysfunction in only 1 region
    • The presence of upper motor neuron signs alone in at least 2 regions
    • The presence of signs above the upper motor neuron signs
  • dont-delay-refer-als

    Could this be ALS? A tool for physicians

    If you are a healthcare provider, use this referral guideline to understand the importance of timely referrals and the difference it can make for patients newly diagnosed or suspected for ALS. 

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