National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Primary lateral sclerosis


Other Names:
Adult-onset PLS; Adult-onset primary lateral sclerosis
Categories:
Primary lateral sclerosis (PLS) is a rare neuromuscular disease that affects the nerve cells that control the voluntary muscles. Problems in the legs (such as weakness, stiffness, spasticity, and balance problems) are often observed first, but hand clumsiness and changes in speech can be early symptoms, as well. The condition is progressive (gradually becomes worse over time); however, affected people have a normal life expectancy. The underlying cause of adult PLS is currently unknown. In most cases, it occurs sporadically in people with no family history of the condition. A subtype of PLS, called juvenile PLS, is caused by changes (mutations) in the ALS2 gene and is inherited in an autosomal recessive manner. Treatment is based on the signs and symptoms present in each person.[1][2][3]
Last updated: 4/14/2017
The signs and symptoms of primary lateral sclerosis (PLS) often develop between the ages of 40 and 60 and progress (become worse) over time. The voluntary muscles of the legs are often involved first, with symptoms beginning in one leg and then progressing to the other. In general, people with PLS may experience:[1][2][3]
  • Muscle weakness
  • Muscle stiffness and spasticity
  • Difficulty with balance and clumsiness
  • Slowed movement
  • Problems with speech
Last updated: 4/13/2017

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Abnormal upper motor neuron morphology
Abnormal shape of upper motor neuron
0002127
Babinski sign 0003487
Generalized hyperreflexia 0007034
30%-79% of people have these symptoms
Dysphagia
Poor swallowing
Swallowing difficulties
Swallowing difficulty
[ more ] 		0002015
EMG: chronic denervation signs 0003444
Loss of speech 0002371
Progressive spastic paraparesis 0007199
Pseudobulbar signs 0002200
Spastic dysarthria 0002464
Spastic gait
Spastic walk
0002064
5%-29% of people have these symptoms
Cervical spinal cord atrophy 0010873
Motor axonal neuropathy 0007002
Percent of people who have these symptoms is not available through HPO
Adult onset
Symptoms begin in adulthood
0003581
Autosomal dominant inheritance 0000006
Hyperreflexia
Increased reflexes
0001347
Slow progression
Signs and symptoms worsen slowly with time
0003677
Spastic tetraparesis 0001285
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Last updated: 7/1/2020
A diagnosis of primary lateral sclerosis (PLS) may be suspected based on the presence of characteristic signs and symptoms. Several different medical tests may then be ordered to confirm the diagnosis and rule out other conditions (such as multiple sclerosis and amyotrophic lateral sclerosis) that can be associated with similar features. These tests may include:[1][2]
Although a preliminary diagnosis of PLS can be made after other conditions are ruled out, it may take repeated testing over three to four years to confirm the diagnosis.[1]
Last updated: 4/13/2017
The treatment of primary lateral sclerosis (PLS) is based on the signs and symptoms present in each person. For example, certain medications may be prescribed to treat the muscle stiffness and/or pain that can be associated with the condition. Physical therapy and occupational therapy can help maintain muscle strength, flexibility and range of motion, and may prevent joint immobility. Assistive devices such as braces, canes, walkers or wheelchairs may be needed for continued mobility. Speech therapy may be recommended when facial muscles are involved.[1][2][3]
Last updated: 4/14/2017

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • The Centers for Mendelian Genomics program is working to discover the causes of rare genetic disorders. For more information about applying to the research study, please visit their website.
  • ClinicalTrials.gov lists trials that are related to Primary lateral sclerosis. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Patient Registry

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Primary lateral sclerosis. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.

  1. Primary lateral sclerosis (PLS). Mayo Clinic. October 2016; http://www.mayoclinic.org/diseases-conditions/primary-lateral-sclerosis/symptoms-causes/dxc-20214456.
  2. Carmel Armon, MD, MSc, MHS. Primary Lateral Sclerosis. Medscape Reference. December 2015; http://emedicine.medscape.com/article/1171782-overview.
  3. Primary Lateral Sclerosis Information Page. National Institute of Neurological Disorders and Stroke. https://www.ninds.nih.gov/Disorders/All-Disorders/Primary-Lateral-Sclerosis-Information-Page. Accessed 4/13/2017.