How is ulnar nerve entrapment diagnosed and treated?

Updated: Apr 26, 2021
  • Author: David M Lichtman, MD; Chief Editor: Harris Gellman, MD  more...
  • Print


Ulnar nerve entrapment as a result of compression in the Guyon canal usually presents as a motor lesion due to isolated involvement of the deep motor branch as it courses around the hook of the hamate.

Patients often have a positive Tinel sign over the Guyon canal with paresthesia in the small and ring fingers. However, sensation is not decreased over the dorsal or ulnar aspect of the hand.

The exact cause of ulnar nerve compression at the wrist can usually be determined by means of careful history taking, physical examination, and imaging studies. MRI is particularly helpful in identifying a space-occupying lesion, such as a ganglion cyst. A good history can help establish the diagnosis of ulnar artery thrombosis or injury due to activities such as walking with crutches, kayaking, and playing handball. [58]

Activity-related neuropathy often is eliminated when the offending activity is stopped. However, with unexplained deep motor branch paralysis, exploration of the Guyon canal is appropriate.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!