Physician The Permanente Medical Group Sacramento, California, United States
Case Diagnosis: Lateral antebrachial cutaneous (LACN) neuropathies are uncommon. The medical literature has less than 100 reported cases – and this is the first known case report of a unilateral lateral antebrachial cutaneous neuropathy from using forearm straps to move heavy furniture.
Case Description: A 46-year-old man presented to PM&R electrodiagnostic clinic with 2 months of left forearm numbness, from mid-forearm to wrist. Symptoms began after using straps on his left forearm to lift appliances, creating sustained pressure on his volar forearm for a few minutes.
Physical exam revealed intact upper extremity strength and reflexes; but diminished light touch sensation in the distal third of his left lateral forearm.
Nerve conduction studies of the LACN revealed an absent SNAP; the right LACN and other nerve studies were normal, as was needle EMG of left upper extremity muscles, including the biceps. Thus, he was diagnosed with a left LACN neuropathy, likely from moving strap compression. He was instructed to avoid further strap use on his forearm. Unfortunately, he was lost to follow up.
Discussions: LACN neuropathy etiologies include windsurfing, biceps rupture, surgical positioning, phlebotomy, steroid injection, and forearm splint use.
This is the first known case report of a LACN neuropathy after moving strap compression on the forearm, from lifting appliances. In this case, the etiology involved compression of the LACN in the volar forearm. However, case reports also describe LACN neuropathies from prolonged elbow flexion; thus, prolonged elbow flexion from moving appliances also may have compressed the LACN, lateral to the biceps tendon.
Conclusions: The medical literature lists less than 100 cases of LACN neuropathies. This is the first known case report of a LACN neuropathy from moving strap compression on the forearm.
Knowledge of this uncommon mononeuropathy will help when seeing patients with forearm paresthesias. This case also highlights electrodiagnostic techniques to study the LACN.
