title: Spinal accessory nerve injury: A potentially missed cause of a painful, droopy shoulder.
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.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.|Lawson Health Research Institute, London, ON, Canada.
authors.forename: Steven
authors.initials: S
authors.lastname: Macaluso
authors.affiliation: Department of Surgery, Division of Plastic Surgery, Roth-McFarlane Hand & Upper Limb Centre, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Ross
authors.affiliation: Department of Physical Medicine and Rehabilitation, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.|Lawson Health Research Institute, London, ON, Canada.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Doherty
authors.affiliation: Department of Surgery, Division of Plastic Surgery, Roth-McFarlane Hand & Upper Limb Centre, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Doherty
authors.affiliation: Department of Physical Medicine and Rehabilitation, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Miller
mesh_terms: D061227:Accessory Nerve Injuries / Q000175:diagnosis*; D000058:Accidental Falls; D000063:Accidents, Traffic; D000328:Adult; D000369:Aged, 80 and over; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D018908:Muscle Weakness / Q000209:etiology*; D009431:Neural Conduction; D012782:Shoulder / Q000294:innervation*; D020069:Shoulder Pain / Q000209:etiology*; D055815:Young Adult
keywords: Nerve; injury; shoulder; trauma