Test: Hoffmann's Reflex

Video Link

Background/Purpose

Hoffmann's reflex, named after Johann Hoffmann, is a finding elicited by a reflex test which can help verify the presence or absence of issues arising from the corticospinal tract. It is also known as the finger flexor reflex or Hoffmann's sign. Usually considered a pathological reflex in a clinical setting, the Hoffmann's reflex has also been used as a measure of spinal reflex processing (adaptation) in response to exercise training.
A positive Hoffmann’s reflex and finger jerks suggest hypertonia, but can occur in healthy individuals, and are not useful signs in isolation. In cerebellar diseases, the reflexes may be pendular, and muscle contraction and relaxation tend to be slow, but these are not sensitive or specific to cerebellar signs.
Hoffmann's reflex is often erroneously called 'the Babinski's sign of the upper limb'. However the two reflexes are quite different, and should not be equated with each other.

A positive Babinski sign is considered a pathological sign of upper motor neuron disease except for infants, in whom it is normal. Whereas, a positive Hoffmann's sign can be present in an entirely normal patient. A positive Hoffmann's sign in the normal patients is more commonly found in those who are naturally hyper-reflexive (e.g. 3+ reflexes). A positive Hoffmann's sign is a worrisome finding of a disease process if its presence is asymmetrical, or has an acute onset.
Another significant difference between Hoffmann's reflex and the Babinski sign are their mechanism of reflex. Hoffmann's reflex is a deep tendon reflex (spindle fibre) with a monosynaptic reflex pathway in Rexed lamina IX of the spinal cord. On the other hand, the plantar reflex is not a deep tendon reflex, and its pathway is both more complicated and not fully understood.

Procedure

The test involves loosely holding the middle finger and flicking the fingernail downward, allowing the middle finger to flick upward reflexively. A positive response is seen when there is flexion and adduction of the thumb on the same hand.
Performed: Unilaterally

Dialog

Flick of the 3rd digit and looking for twitch of the 1st or 2nd digit.

Criteria

• No reaction of thumb or 2nd digit

Measurement

0.00

LOINC Code

0

Scale/Grading

Pass/Fail