抄録
Guyon canal syndrome is a well known entrapment syndrome of the ulnar nerve at the wrist joint level. Soft tissue tumors much as ganglions have been reported as the main cause. We experienced a rare case of Guyon canal syndrome, caused by a deep branch of the ulnar artery. The case was a 75 year-old female. She complained of discomfort feeling at the palmo-ulnar area of the left ring and little fingers. We suspected the Guyon canal syndrome from the physical findings, and the examination of the conduction velocity of the ulnar nerve. We could not detect, however, any cause for it from MRI. We performed therefore, an operative exploration into the Guyon Canal. Then we found a branch of the ulnar artery running deeply over the palmer side of the ulnar nerve. And we noted also a pseudoneuroma lying on the ulnar nerve at just proximal to the crossing point of the arterial branch. We diagnosed that this arterial branch was causing the entrapment of the ulnar nerve. So we cut it out with electro-coagulation.
We do not know why such a deep arterial branch, possibly an anatomical anomaly, can cause compression to the ulnar nerve for the first time at the age of 75. However, it is important that we should keep in mind that such an arterial branch also could cause the Guyon Canal Syndrome.
