404 - A Case Study on Radial Neuropathy in an Otherwise Healthy 41-year-old Male post Biceps Tendon Tear

This case study provides an example of PIN syndrome and superficial radial nerve neuropathy in an otherwise healthy 41-year-old male who underwent surgery for a torn left biceps tendon. 

Case Description:

A 41-year-old left hand dominant male presented to the PM&R clinic for EMG consultation due to left hand weakness. He stated that he fell while pushing his daughter on a swing and tore his biceps tendon, eventually undergoing biceps tendon repair. Since the screw removal, he reported having weakness of the left hand. He endorsed intermittent tingling in the left lateral forearm, left finger drop, and weakness in the left wrist. He denied having radiating pain to the arms or paresthesias in the feet. Sensation to light touch was diminished in the radial nerve distribution and was intact in the rest of the upper extremities bilaterally. Tinel’s sign was negative at the wrist. The electrodiagnostic studies were consistent with a diagnosis of left radial neuropathy involving both the superficial radial and posterior interosseous nerves. Active denervation with no signs of reinnervation was noted. 

Discussions:

In general, neuropathies of the radial nerve and its branches are rarer than other upper extremity neuropathies such as carpal tunnel syndrome.1 Neuropathy of the superficial branch of the radial nerve, also known as Wartenberg syndrome or “cheiralgia paresthetica,” is a purely sensory neuropathy. Cheiralgia paresthetica can cause paresthesias and numbness of the dorsolateral distal forearm and hand.2 Unlike cheiralgia paresthetica, PIN syndrome can cause both sensory and motor symptoms, sometimes presenting with weakness on extension of the involved fingers and thumb.3 A careful physical exam and electrodiagnostic studies are required due to the difficulty in differentiating the symptoms associated with both syndromes. 

Conclusions:

 This case study provides an example of both cheiralgia paresthetica and PIN syndrome post biceps tendon repair.