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Amyotrophic lateral sclerosis

  • Alternative Names

    Lou Gehrig's disease; ALS; Upper and lower motor neuron disease; Motor neuron disease


    Symptoms usually do not develop until after age 50, but they can start in younger people. Persons with ALS have a loss of muscle strength and coordination that eventually gets worse and makes it impossible to do routine tasks such as going up steps, getting out of a chair, or swallowing.

    Breathing or swallowing muscles may be the first muscles affected. As the disease gets worse, more muscle groups develop problems.

    ALS does not affect the senses (sight, smell, taste, hearing, touch). It only rarely affects bladder or bowel function, or a person's ability to think or reason.

    Symptoms include:

    • Difficulty breathing
    • Difficulty swallowing
      • Choking easily
      • Drooling
      • Gagging
    • Head drop due to weakness of the neck muscles
    • Muscle cramps
    • Muscle contractions called fasciculations
    • Muscle weakness that slowly gets worse
      • Commonly involves one part of the body first, such as the arm or hand
      • Eventually leads to difficulty lifting, climbing stairs, and walking
    • Paralysis
    • Speech problems, such as a slow or abnormal speech pattern (slurring of words)
    • Voice changes, hoarseness
    • Weight loss

    Signs and tests

    The health care provider will take a medical history, which includes strength and endurance.

    A physical examination of strength shows weakness, often beginning in one area. There may be muscle tremors, spasms, twitching, or loss of muscle tissue (atrophy). Atrophy and twitching of the tongue are common.

    The person's walk may be stiff or clumsy. Reflexes are abnormal. There are increased reflexes at the joints, but there may be a loss of the gag reflex. Some patients have trouble controlling crying or laughing. This is sometimes called "emotional incontinence."

    Tests that may be done include:

    • Blood tests to rule out other conditions
    • Breathing test to see if lung muscles are affected
    • Cervical spine CT or MRI to be sure there is no disease or injury to the neck, which can mimic ALS
    • Electromyography to see which nerves do not work properly
    • Genetic testing, if there is a family history of ALS
    • Head CT or MRI to rule out other conditions
    • Nerve conduction studies
    • Swallowing studies
    • Spinal tap (lumbar puncture)