A case of Guyon syndrome with neuroapraxic block resolved after surgical decompression

Guyon syndrome is the well-known ulnar entrapment at the wrist; usually surgical decompression improves the symptoms. Neurophysiological studies are essential to demonstrate the abnormality of ulnar nerve conduction at the wrist. We report a case of Guyon syndrome onset after 6 h of cycling. Neurophysiological study revealed ulnar neuroapraxic block at the wrist, and axonal impairment. Post-operative clinical and neurophysiological follow-up showed marked clinical improvement and neurophysiological resolution of abnormalities. To our knowledge, no cases of Guyon syndrome with neuroapraxic block are reported in the literature.