Double Crush Syndrome

Double crush syndrome was first described in The Lancet in 1973. The term refers to a diagnosis of a compressed or trapped nerve in one area (e.g. the carpal tunnel in the wrist or Guyon's tunnel in the elbow), with a second entrapment in another location (e.g. the neck or shoulder) along the course of the entire nerve, with both entrapments contributing to symptoms. Some researchers suggest that the presence of an undiagnosed entrapment in another location may explain why some people still experience symptoms after carpal tunnel surgery. Some also suggest that an examination of the hand alone is not sufficient when diagnosing and treating carpal tunnel syndrome, and that the nerves along the whole length of the arm should be examined from the hand to the neck. Double crush conditions may affect either the upper extremity or the lower extremity. It is vital that the possibility of concurrent problems be evaluated prior to any surgical steps.    

In CTS, many times the nerves to the hand are damaged due to injuries of the wrist along with concurrent injuries ranging from the forearm to the upper neck ("Double Crush"). Like the situation with the wire, the effects of the damage occurring at the wrist are exaggerated due to the other injury site, thus producing more pronounced wrist and hand symptoms. If this additional site of injury is overlooked and not treated, it will result in the incomplete resolution of CTS. It also will be a factor in the success of surgical procedures performed on the wrist itself.