gms | German Medical Science

Objectives/Interrogation: Ulnar nerve compression can happen along its path in the upper limb, being more common, according to its anatomy, around the elbow. Its distal compression, at guyon canal, is rare but globally the ulnar entrapment is the second most common peripheral nerve entrapment neuropathy in the upper limb.

Ulnar compression at the Guyon’s canal can be caused by a number of factors, including acute or repetitive trauma, carpal bone fractures, additional muscles, tumors (lipoma, ganglion), diseases of the neighboring vessels, metabolic/degenerative diseases. The distal cubital lesion is classified according to its location in the Guyon’s canal and consequently the symptomatology that causes.

Methods: The authors present a case of a 58 year-old female patient with progressive loss of muscular strength with an acute onset, associated with paresthesia in the 4th and 5th fingers, of her right hand. With no history of recent trauma. In the physical examination the muscular atrophy of the thenar and hypothenar eminence was notorious. Wartenberg, Jeanne’s and Froment’s signs were positive, with no sensory dorsal alterations, no palpable masses, no traumatic lesions identified.

Electromyography showed a compression of the ulnar nerve at the wrist level, in the Guyon canal, mainly motor.

Surgical decompression at the Guyon canal was decided, with identification and resection of a synovial cyst deeper to the ulnar nerve, at the carpal bones, causing ulnar nerve compression.

Results and Conclusions: Six months after the surgical procedure with electromyography showing improvements compared with the pre operative exam.

Twelve-months follow up with improvement of the muscular strength and trophism, hand movements specially grasp, pinch, thumb adduction and 4th and 5th fingers’ movement and paresthesia.

Conclusion: Compression of the ulnar nerve is the second most common cause of nerve compression of the upper limb, although, its distal compression is rare. Medical history, physical examination and complementary studies allow its diagnosis, identification of the most probable etiology and help in its posterior treatment approach.