Primary lateral sclerosis (PLS)
Primary lateral sclerosis (PLS)
Primary lateral sclerosis (PLS) causes weakness in your voluntary muscles, such as those you use to control your legs, arms and tongue. Primary lateral sclerosis is a type of motor neuron disease, which causes muscle nerve cells to slowly die, causing weakness.
Primary lateral sclerosis can happen at any age, but it's more common after age 40. 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.
Primary lateral sclerosis is often mistaken for another, more common motor neuron disease called amyotrophic lateral sclerosis (ALS). However, primary lateral sclerosis progresses more slowly than ALS, and in most cases isn't considered fatal.
Signs and symptoms of primary lateral sclerosis typically take years to progress. They include:
Less commonly, PLS begins in the tongue or hands, and then progresses down the spinal cord to the legs.
When to see a doctor
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.
Adult primary lateral sclerosis
Juvenile primary lateral sclerosis
Juvenile primary lateral sclerosis is an autosomal recessive disease, meaning that both parents have to be carriers of the gene to pass it to their child, even though they don't have the disease themselves.
Although the average progression of primary lateral sclerosis lasts around 20 years, the disease has highly variable effects from person to person. Some people may be able to continue to walk, but others will eventually need wheelchairs or other assistive devices for mobility or other activities.
Adult PLS isn't considered to shorten life expectancy, but it may gradually affect the quality of your life as more muscles become disabled. Weaker muscles may cause you to fall more, which may result in injuries.
Tests and diagnosis
There is no single test that confirms a diagnosis of primary lateral sclerosis. In fact, because the disease can mimic signs and symptoms of other neurological diseases such as multiple sclerosis and ALS, several tests are done to rule out other diseases.
After taking a careful record of your medical history and performing a complete neurological examination, your doctor may order the following tests:
After other diseases are ruled out, your doctor may make a preliminary diagnosis of PLS. Sometimes doctors wait three to four years before being sure of the 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.
Treatments and drugs
The treatments for primary lateral sclerosis focus on relieving symptoms and preserving function. There are no treatments to prevent, stop or reverse PLS. Treatments include:
Lifestyle and home remedies
Although there's no cure for primary lateral sclerosis, there are a few lifestyle choices you can make to preserve muscle function for as long as possible:
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:
Last Updated: 2010-10-16
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