Compass is still being developed and is effectively in beta. Some content and features may be incomplete, change, or not work as expected.

Content is anchored to trusted sources where available, but Compass has not yet been clinically reviewed. It provides general information rather than medical advice.

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Tests and measurements

Nerve conduction study

A test measuring how fast and how strongly signals travel along nerves, using small electrical pulses on the skin.

What it means

Pads on the skin deliver a brief pulse and record what arrives further along. It shows whether the nerve fibre itself is conducting normally, which helps separate ALS/MND from other conditions that can look similar.

Why you might hear it

  • It is usually done in the same appointment as an EMG.
  • Much of its value is in ruling other things out.

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.