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What is hoffman reflex? - A complete guide

Hoffmann’s reflex is a type of pathological reflex, named after Johann Hoffmann
This reflex is used to assess the uppermotorneuron injury.
Compared to the Babinski relfex where you test the foot and observe for the response it is used in upperlimb the fingers.
Other names of Hoffman reflex
This is alo called as finger flexor reflex
The Babinski's sign of the upper limb'
Trömner signs
How to test for hoffman reflex? 
A terminal phalanx of the middle linger of the patient is flicked downwards between the examiner’s thumb and index finger quickly
Positive Hoffman's sign— In states of hypertonia  the tip of the fingers flex and the thumb flexes and adducts.
Positioning the neck in extension (sometimes flexion) sometimes worsen the reflex

What is the clinical significance of hoffman reflex?
As already mentioned it is a pathological reflex. pathological reflex is not a normal muscle-tendon reflex that should be present.
It is an early sign of pyramidal disease.The Hoffmann’s sign is observed in upper motor neuron lesion (UMNL). The upper motor neuron injury mean that there is damage to the spinal cord and/or brain.
Hoffmann Sign is considered as a Red Flag for Cervical Myelopathy
The  Hoffmann sign is a reliable way to test for early signs of cervical myelopathy. The presence of Hoffmann sign on both sides strongly suggests the presence of spinal cord compression in the cervical spine
False positive and false negative  Hoffman reflex
It is seen in the following conditions
  • Multiple sclerosis
  • ALS 
  • Diseases which cause spinal cord compression (myelopathy) such as cervical spondylitis, tumors, or degenerative arthritis.  A Hoffmann reflex can also happen in the presence of generalized hyperreflexia (overactive reflexes) as seen with anxiety or hyperthyroidism.
However, this test is not foolproof as the patients who don’t have cervical myelopathy can have a positive Hoffmann sign. A positive Hoffmann sign may be  seen in patients with hyperthyroidism, anxiety disorders, and other conditions that involve increased deep tendon reflexes.
Sometimes patients with true cervical myelopathy do not have a positive Hoffman’s sign.
the Hoffmann test is not a reliable screening tool for predicting the presence of cervical spinal cord compression.
It is the sensitivity of this test which makes the Hoffmann test useful to the neurologist
Comparison of Babinskis sign and Hoffman reflex
  • A positive Babinski sign is a pathological sign of upper motor neuron disease except for infants, in whom this reflex is normal .A positive Hoffmann's sign can be present in an entirely normal patient, it is more commonly found in those who are naturally hyper-reflexive (e.g. 3+ reflexes).A positive Hoffmann's sign is considered as a  worrisome finding if its presence is asymmetrical, or has an acute onset.
  • Hoffmann's reflex and the Babinski sign also differ in their mechanism . Hoffman's reflex is a deep tendon reflex (spindle fibre) with a monosynaptic reflex pathway . The plantar reflex is not a deep tendon reflex, and its pathway is both more complicated and not fully understood.
  • Both these signs indicate damage in the corticospinal track.The Babinski sign indicates damage anywhere along the corticospinal track.  However, the Hoffman and Tromner signs are more specific that they indicate a lesion or damage above the C5 or C6 level of the cervical spine