What is primary lateral sclerosis?
Primary lateral sclerosis is a type of motor neuron disease that causes muscle nerve cells to slowly break down, causing weakness. Primary lateral sclerosis (PLS) causes weakness in your voluntary muscles, such as those you use to control your legs, arms and tongue.
How common is primary lateral sclerosis?
Primary lateral sclerosis is rare. It can happen at any age, but it usually occurs between ages 40 and 60. A subtype of primary lateral sclerosis, known as juvenile primary lateral sclerosis, begins in early childhood and is caused by an abnormal gene passed from parents to children. Please discuss with your doctor for further information.
What are the symptoms of primary lateral sclerosis?
The common symptoms of primary lateral sclerosis are:
- Stiffness, weakness and spasticity in your legs
- Tripping, difficulty with balance and clumsiness as the leg muscles weaken
- Weakness and stiffness progressing to your trunk, then your arms, hands, tongue and jaw
- Hoarseness, reduced rate of speaking, slurred speech and drooling as the facial muscles weaken
- Difficulties with swallowing and breathing late in the disease
Less commonly, PLS begins in your tongue or hands and then progresses down your spinal cord to your legs.
There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.
When should I see my doctor?
You should contact your doctor if you have any of the following:
- Persistent problems with stiffness or weakness in your legs, or with swallowing or speaking.
If your child develops involuntary muscle spasms or seems to be losing balance more often than usual, make an appointment with a pediatrician for an evaluation.
What causes primary lateral sclerosis?
The exact cause of primary lateral sclerosis is not known. Most cases seem to occur randomly, for no apparent reason (sporadically). Primary lateral sclerosis is one of a group of disorders known as motor neuron diseases. Motor neuron diseases are characterized by malfunction of the nerve cells (motor neurons) within the brain and spinal cord that carry instructions from the brain to the muscles.
What increases my risk for primary lateral sclerosis?
Please discuss with your doctor for further information.
Diagnosis & treatment
The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.
How is primary lateral sclerosis diagnosed?
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:
- 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.
How is primary lateral sclerosis treated?
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:
- 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 changes & home remedies
What are some lifestyle changes or home remedies that can help me manage primary lateral sclerosis?
The following lifestyles and home remedies might help you cope with primary lateral sclerosis:
- 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.
If you have any questions, please consult with your doctor to better understand the best solution for you.
Hello Health Group does not provide medical advice, diagnosis or treatment.
Review Date: November 28, 2017 | Last Modified: December 8, 2019
Primary lateral sclerosis (PLS). https://www.mayoclinic.org/diseases-conditions/primary-lateral-sclerosis/symptoms-causes/syc-20353968. Accessed November 28, 2017.
Primary Lateral Sclerosis. https://rarediseases.org/rare-diseases/primary-lateral-sclerosis/. Accessed November 28, 2017.
Primary Lateral Sclerosis. https://www.webmd.com/brain/primary-lateral-sclerosis-10673. Accessed November 28, 2017.