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Primary Lateral Sclerosis Vs. ALS


Primary lateral sclerosis (PLS) is a motor neuron disease variation of ALS (amyotrophic lateral sclerosis) but far more rare. PLS refers to patients who seem to have disruptions with only upper motor neurons and not lower motor neurons. It is possible, however, for PLS to progress to ALS.


PLS causes weakness in the voluntary muscles that control your legs, arms, and tongue. It can happen at any age, but usually occurs between 40 and 60. It can also be caused in children by an abnormal gene inherited by the child from their parents.

Primary Lateral Sclerosis Symptoms

Symptoms of PLS can include the following:

  • Weakness and stiffness in your legs
  • Difficulty balancing and clumsiness as leg muscles weaken
  • Weakness in the trunk, arms, hands, tongue, and jaw
  • Slowness of speech or slurred speech and drooling as facial muscles weaken

PLS does not progress as quickly as ALS. While it can affect quality of life, working with a team of specialists can help you maintain fulfilling activities.

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