Although the average progression of primary lateral sclerosis (PLS) 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 to use wheelchairs or other assistive devices.

Adult PLS isn't thought 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.

Jul. 12, 2013