There is no single test that confirms a diagnosis of primary lateral sclerosis (PLS). In fact, because the disease can mimic signs and symptoms of other neurological diseases such as multiple sclerosis and ALS, your doctor may order several tests to rule out other diseases.

After taking a careful record of your medical history and family history and performing a neurological examination, your doctor may order the following tests:

  • Bloodwork. You'll have blood tests to check for infections or other possible causes of muscle weakness.
  • Magnetic resonance imaging (MRI). An MRI or other imaging tests of your brain or spine may reveal signs of nerve cell degeneration.

    Your doctor may also order an MRI to look for other causes of your symptoms, such as structural abnormalities, multiple sclerosis or spinal cord tumors.

  • Electromyogram (EMG). During an EMG, your doctor inserts a needle electrode through your skin into various muscles. The test evaluates the electrical activity of your muscles when they contract and when they're at rest.

    This test can measure the involvement of lower motor neurons, which can help to differentiate between PLS and ALS.

  • Nerve conduction studies. These tests use a low amount of electrical current to test and measure your nerves' ability to send impulses to muscles in different areas of your body. This test can determine if you have nerve damage.
  • Spinal tap (lumbar puncture). In this procedure, your doctor uses a thin, hollow needle to remove small samples of the cerebrospinal fluid — surrounding your brain and spinal cord — from within your spinal canal for laboratory analysis. A spinal tap can help rule out multiple sclerosis, infections and other conditions.

After other diseases are ruled out, your doctor may make a preliminary diagnosis of PLS.

Sometimes doctors wait three to four years before giving a diagnosis, because early amyotrophic lateral sclerosis (ALS) can look just like PLS until additional symptoms surface a few years later. You may be asked to return for repeat electromyography testing over three to four years before the PLS diagnosis is confirmed.


Treatment for primary lateral sclerosis (PLS) focuses on relieving symptoms and preserving function. There are no treatments to prevent, stop or reverse PLS. Treatments include:

  • Medication. Your doctor may prescribe medication to relieve muscle spasms (spasticity), such as baclofen, tizanidine (Zanaflex) or clonazepam (Klonopin). These medications are taken by mouth (orally).

    If your spasticity isn't controlled with oral medication, your doctor may recommend surgically implanting a medication pump to deliver baclofen directly to your spinal fluid (intrathecal baclofen).

    If you experience depression, your doctor may prescribe antidepressants. Amitriptyline and other drugs also can help drooling problems.

  • Physical therapy. Stretching and strengthening exercises may help to maintain muscle strength, flexibility and range of motion, and to prevent joint immobility. Heating pads can help relieve your symptoms of muscle pain.
  • Speech therapy. If your facial muscles are affected by PLS, speech therapy can help you compensate for speech and facial muscle problems.
  • Assistive devices. You may be evaluated periodically by physical or occupational therapists to determine whether you need assistive devices, such as a cane, walker or wheelchair, as PLS progresses.

Lifestyle and home remedies

Although there's no cure for primary lateral sclerosis, you can make a few lifestyle choices to preserve muscle function for as long as possible:

  • Stay active. Continue activity or exercise programs as long as you can comfortably and safely do so. Staying active may help you keep your existing function and slow the progression of the disease.

    Be sure you stay safe, keeping in mind that your muscle weakness puts you at higher risk of tripping and falling.

  • Eat a healthy diet. Because PLS can cause your activity level to slow down, be sure you're eating a nutritious diet to avoid excessive weight gain and added pressure on your joints.

Coping and support

Periods of feeling down about having primary lateral sclerosis are expected and normal. Dealing with the reality of an incurable, progressive disease can be challenging. To cope with the disease and its effects, consider these tips:

  • Seek emotional support. Family and friends can be great sources of comfort and support when you're wrestling with the emotional aspects of long-term disease.

    Because primary lateral sclerosis is an uncommon diagnosis, it might be a challenge to find a local support group for people with your condition. However, some online discussion groups are available, and it may be helpful to see how others have coped with the disease.

  • Get professional help if you need it. When faced with a chronic illness, it's not unusual to become overwhelmed at times. Seek out professional counseling for another perspective, or if you're struggling with depression and need advice on treatment.
  • Know and use resources available to you. If you reach a point where your disease is restricting your activities significantly, ask your doctor about devices designed to help you stay independent.

    In addition, there are social services available to people with disabilities of all kinds. Try to learn all you can about the resources available to you. Sometimes relying on your community for help can strengthen ties in new ways.

Oct. 19, 2016
  1. Daroff RB, et al. Disorders of upper and lower motor neurons In: Bradley's Neurology in Clinical Practice. 7th ed. Philadelphia, Pa.: Saunders Elsevier; 2016. https://www.clinicalkey.com. Accessed June 1, 2016.
  2. Jorgensen S, et al. Motor neuron diseases. In: Braddom's Physical Medicine and Rehabilitation. Philadelphia, Pa.: Elsevier; 2016. https://www.clinicalkey.com. Accessed June 1, 2016.
  3. Elman LB, et al. Clinical features of amyotrophic lateral sclerosis and other forms of motor neuron disease. http://www.uptodate.com/home. Accessed June 1, 2013.
  4. NINDS primary lateral sclerosis information page. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/primary_lateral_sclerosis/primary_lateral_sclerosis.htm. Accessed June 1, 2016.
  5. Tomik B, et al. Pure primary lateral sclerosis – Case reports. Clinical Neurology and Neurosurgery. 2008;110:387.
  6. Juvenile primary lateral sclerosis. Genetics Home Reference. https://ghr.nlm.nih.gov/condition/juvenile-primary-lateral-sclerosis. Accessed June 1, 2016.
  7. Statland JM, et al. Primary lateral sclerosis. Neurology Clinics. 2015;33:749.
  8. NINDS Motor neuron diseases information page. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/motor_neuron_diseases/motor_neuron_diseases.htm. Accessed June 1, 2016.