Affiliations: [a] Department of Physical Medicine and Rehabilitation, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada | [b] Department of Surgery, Division of Plastic Surgery, Roth-McFarlane Hand & Upper Limb Centre, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada | [c] Lawson Health Research Institute, London, ON, Canada
Correspondence:
[*]
Corresponding author: Steven Macaluso, Department of Physical Medicine and Rehabilitation, Parkwood Institute, St. Joseph's Health Care, 550 Wellington Road, London, Ontario, N6C 0A7, Canada. Tel.: +1 519 685 4292 ext. 45062; Fax: +1 519 685 4017; E-mail:steven.macaluso@sjhc.london.on.ca
Abstract: BACKGROUND: Spinal accessory nerve (SAN) injury can be an
overlooked cause of scapular winging and shoulder dysfunction. The most
common etiology is iatrogenic injury following surgical procedures at the
posterior triangle of the neck. We present three cases of isolated injury to
the SAN following trauma. OBJECTIVE: To improve detection of SAN injuries through
highlighting the clinical presentation, diagnosis and treatment via three
cases in which the injuries were initially missed. METHODS: Clinical case series and narrative review. RESULTS: Three (3) patients were evaluated by history, physical
exam and electrodiagnostic study (EMG). Clinical symptoms included, a
painful, droopy shoulder and difficulties with overhead activities. Clinical
signs included the observation of scapular winging, and focal atrophy of the
trapezius and in some cases the sternocleidomastoid (SCM). Novel clinical
signs such as the active elevation lag sign and triangle sign were also
helpful clinically to highlight the SAN as the site of pathology. EMG
revealed denervation and reduced motor unit recruitment in the trapezius and
SCM. CONCLUSIONS: Early detection of SAN injuries can be improved
through appropriate clinical suspicion, a detailed history and careful
physical exam. EMG testing can help guide prognosis, direct conservative and
surgical treatment, and reduce patient morbidity.
