[Reverse Chaddock sign]

Area of Science:

• Neurology
• Neuroscience
• Clinical Assessment

Context:

• The Babinski reflex is a key indicator of upper motor neuron lesions.
• Existing methods like the Babinski reflex can yield false positives.
• Alternative pathological reflexes are less consistently sensitive.

Purpose:

• To evaluate the sensitivity and reliability of the Chaddock reflex and a novel "reversed Chaddock method" for eliciting an upgoing great toe response.
• To compare these methods with the traditional Babinski reflex.
• To identify an optimal receptive field for eliciting pathological reflexes.

Summary:

• The Babinski reflex, elicited by stroking the sole, is prone to false results.
• The Chaddock reflex, stimulating the external malleolar area, is sensitive.
• The "reversed Chaddock method" (stimulating the dorsum medially to laterally) is equally sensitive and avoids false positives, suggesting the sural nerve territory is key.

Impact:

• The "reversed Chaddock method" provides a reliable alternative to the Babinski reflex.
• This technique can improve diagnostic accuracy for pyramidal tract dysfunction.
• It offers a valuable tool for clinical neurological examinations, potentially reducing misdiagnosis.