Combined injury of the accessory nerve and brachial plexus.
BACKGROUND
Stretch-induced spinal accessory nerve palsy has been considered extremely rare, with only a few cases reported.


OBJECTIVE
In 357 patients with stretch lesions of the brachial plexus, we investigated the prevalence, course, and surgical treatment of accessory nerve palsy.


METHODS
Accessory nerve palsy was ascertained when the patient was unable to shrug the ipsilateral shoulder. Patients underwent brachial plexus reconstruction between 6 and 8 months after trauma. To confirm paralysis, during surgery, the accessory nerve was stimulated electrically.


RESULTS
Accessory nerve palsy occurred in 19 of the 327 patients (6%) with upper type or complete palsy of the brachial plexus. Proximal injuries of the accessory nerve accompanied by voice alteration and complete palsy of the sternocleidomastoid and trapezius muscle occurred in 2 patients. Proximal palsy without vocal alterations was observed in 6 patients. Palsy of the trapezius muscle with preservation of the sternocleidomastoid muscle occurred in 11 patients. All 7 patients who demonstrated muscle contractions upon electrical stimulation of the accessory nerve during surgery recovered completely. Patients with surgical reconstruction of the accessory nerve through grafting (n = 2) or repair by platysma motor nerve transfer (n = 2) recovered active shoulder shrugging within 36 months of surgery. Seven of the 8 patients without accessory nerve reconstruction recovered from their drop shoulder and head tilt, but remained unable to shrug.


CONCLUSIONS
If intraoperative electrical stimulation produces contraction of the upper trapezius muscle, no repair is needed. In proximal injuries, the platysma motor branch should be transferred to the accessory nerve; whereas in paralysis distal to the sternocleidomastoid muscle, the accessory nerve should be explored and grafted.
Department of Orthopedic Surgery, Governador Celso Ramos Hospital. Florianópolis, Santa Catarina, Brazil. bertelli@matrix.com.br
Jayme Augusto
JA
Bertelli
Marcos Flávio
MF
Ghizoni
D000055:Accessory Nerve / Q000601:surgery; D020436:Accessory Nerve Diseases / Q000453:epidemiology* / Q000209:etiology* / Q000601:surgery; D061227:Accessory Nerve Injuries; D000328:Adult; D001917:Brachial Plexus / Q000293:injuries* / Q000601:surgery; D020516:Brachial Plexus Neuropathies / Q000150:complications* / Q000601:surgery; D006801:Humans; D010243:Paralysis / Q000209:etiology; D015995:Prevalence; D012189:Retrospective Studies