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Symptoms and clinical language

Progressive muscular atrophy

A related condition affecting only the lower motor neurons, with weakness and wasting rather than stiffness.

What it means

The mirror image of PLS: only the second relay of the movement pathway is involved. Muscles weaken, lose bulk and twitch, without the stiffness and exaggerated reflexes of upper motor neuron change. Some people diagnosed with it are later found to have ALS/MND.

Why you might hear it

  • It may be used while a diagnosis is being refined.
  • It appears in trial eligibility criteria.

People who may help

Where Compass goes into this

About this explanation

These are plain explanations of words you may come across, not advice about your own situation. Where a word matters to a decision, the question pages go into it properly, and your own team is the place to take it.