Primary lateral sclerosis (PLS) is a rare neuromuscular disease with slowly progressive weakness in voluntary muscle movement. PLS belongs to a group of disorders known as motor neuron diseases. PLS affects the upper motor neurons (also called corticospinal neurons) in the arms, legs, and face. It occurs when nerve cells in the motor regions of the cerebral cortex (the thin layer of cells covering the brain which is responsible for most higher level mental functions) gradually degenerate, causing movements to be slow and effortful. The disorder often affects the legs first, followed by the body, trunk, arms and hands, and, finally the bulbar muscles (muscles that control speech, swallowing, and chewing). Symptoms include weakness, muscle stiffness and spasticity, clumsiness, slowing of movement, and problems with balance and speech. PLS is more common in men than in women, with a varied gradual onset that generally occurs between ages 40 and 60. PLS progresses gradually over a number of years, or even decades. Scientists do not believe PLS has a simple hereditary cause. The diagnosis of PLS requires extensive testing to exclude other diseases. When symptoms begin, PLS may be mistaken for amyotrophic lateral sclerosis (ALS) or spastic paraplegia. Most neurologists follow an affected individual's clinical course for at least 3 to 4 years before making a diagnosis of PLS..
Spastic Paraplegia Foundation 7700 Leesburg Pike, Email: information@sp-foundation.org www.sp-foundation.org Ste 123 Falls Church, VA 22043 information@sp-foundation.org http://www.sp-foundation.org Tel: 1-877-SPF-GIVE (1-877-773-4483) Fax: 877-SPF-GIVE |
ALS Association 1275 K Street, N.W. Suite 1050 Washington, DC 20005 advocacy@alsa-national.org http://www.alsa.org Tel: 202-407-8580 Fax: 202-289-6801 |
Prepared by:
Office of Communications and Public Liaison
National Institute of Neurological Disorders and Stroke
National Institutes of Health
Bethesda, MD 20892
NINDS health-related material is provided for information purposes only and does not necessarily represent endorsement by or an official position of the National Institute of Neurological Disorders and Stroke or any other Federal agency. Advice on the treatment or care of an individual patient should be obtained through consultation with a physician who has examined that patient or is familiar with that patient's medical history.
All NINDS-prepared information is in the public domain and may be freely copied. Credit to the NINDS or the NIH is appreciated.
Last updated October 18, 2012