Increased jitter at single fiber EMG

What it means

The variation in the time interval between the two action potentials of the same motor unit is called jitter. This term therefore applies to increased variability in the interval between successive action potentials of the same motor unit, which is measured by electromyography (EMG).

Increased jitter values are not pathogonomic for myasthenia, but indicate disturbed neuromuscular transmission.

Rare diseases that can present with this1

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: Increased jitter at single fibre electromyography · Increased jitter at single fibre EMG