Cubital Tunnel Syndrome Presenting With Carpal Tunnel Symptoms: Clinical Evidence for Sensory Ulnar-to-Median Nerve Communication.

The authors present a case study of a patient who presented with symptoms consistent with carpal tunnel syndrome but without any of the clinical signs of median nerve compression.  On examination the patient’s symptoms were reproduced with provocative testing of the cubital tunnel (specifically positive Tinel’s test at the elbow with radiation to the thumb and index finger).  Electrodiagnostic testing showed no signs of median nerve pathology but did show a slowing of conduction velocity across the elbow.  There were no signs of aberrant nerve communication.  The patient’s symptoms resolved with ulnar nerve release and anterior subcutaneous transposition.
 
The authors reviewed the literature regarding median-to-ulnar nerve communication in the forearm.  They discussed nerve communication in the forearm including the Martin–Gruber communication (median-to-ulnar) and Marinacci syndrome (ulnar-to-median).  They also discussed ulnar-to-median nerve communication in the palm including the Riches-Cannieu communication (motor) and the Berrettini branch (pure sensory communication).
 
The authors stress the importance of a thorough clinical examination, paying attention to any discrepancies between the symptoms and provocative tests.  These inconsistencies may indicate the presence of aberrant nerve communication and may alter surgical management.