Chaddock reflex

What it means

A diagnostic reflex elicited by stimulation of the skin over the surface of the lateral malleolus of the foot. The Chaddock refelx is present if there is extension of one or more or all of the toes with or without fanning of them when the external inframalleolar skin is stimulated. The Chaddock sign, similar to the Babinski sign, is taken to be an indication of disease of the spinocortical (pyramidal) tract.

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