Mononeuropathy - Wrist Drop - Radial Nerve (C5-C8) Palsy

 

Thank you for asking me Harry who presented with weakness in his hands.

 

The salient findings on examination were weakness of wrist extension, finger extension with/without triceps extension (lost if lesion is above spiral groove) with/without weakness of forearm supination (if at level of spiral groove), with sensory loss over first dorsal interosseus (anatomical snuffbox), which is consistent with a radial nerve palsy at the level of spiral groove/above the spiral groove/below the spiral groove.

 

On general inspection, the patient was comfortable will nil apparent aids.

 

In the upper limbs, there was/was not muscle wasting. There were/were not surgical scars.

 

Tone was reduced/increased/normal.

 

There was asymmetrical weakness in wrist extension, finger extension, elbow extension (if above spiral groove), and supination (if at spiral groove). Finger abduction and adduction were normal (hold hand flat to assess abduction).  

 

Reflexes were reduced in the brachioradialis and triceps (if lesion is in the axilla).

 

Coordination was normal.

 

Sensation was reduced over the first dorsal interosseous (anatomical snuffbox) and posterior surface of the forearm and triceps (if lesion is above upper third of humerus).

 

My findings are consistent with a radial nerve palsy at the level of proximal forearm/spiral groove/axilla

 

​

 

 

 

 

 

 

 

 

 

 

Differentials for wrist drop include:

• C7/C8 nerve root or plexus injury (cervical spondylosis, brachial plexus injury) - weakness of wrist extension, finger extension and flexion, radial deviation of the wrist on attempted extension, absent triceps reflex

• Posterior interosseus nerve lesion (rare) - wrist extension, weakness of finger extension, no sensory loss and normal reflexes

• Peripheral neuropathy

• Motor neuron disease

• Corticospinal tract - hemiparesis