By Michael Rubin, MD
Professor of Clinical Neurology, Weill Cornell Medical College
Dr. Rubin reports no financial relationships relevant to this field of study.
Scapular winging is an occasional finding on a neurological examination, rarely a chief complaint, and usually is caused by long thoracic nerve or spinal accessory nerve lesions.
Seror P, Lenglet T, Nguyen C, et al. Unilateral winged scapula: Clinical and electrodiagnostic experience with 128 cases, with special attention to long thoracic nerve. Muscle Nerve 2018;57:913-920.
Classically associated with long thoracic nerve (LTN) palsy, winged scapula may be static, due to a fixed deformity of the shoulder girdle, spine, or ribs, or dynamic, due to a neuromuscular disorder. Often asymptomatic, it can be missed on examination, but symptoms of pain, weakness, and cosmetic deformity may bring it to medical attention. What are the clinical and electrodiagnostic (EDX) patterns of scapular winging?
Among 128 patients referred for clinical and EDX examination over a 25-year period for unilateral winged scapula and pain at the Clinical Neurophysiology Department at Pitié-Salpêtrière Hospital in Paris, data on 109 patients were collected prospectively between 2001-2016, with 19 added retrospectively from 1992-2000. Information gathered included age, gender, handedness, duration of symptoms, history of onset, and thorough neuromuscular examination. Scapular winging was defined as medial when it occurred near the spine, lateral when it occurred near the axilla, static when it was present at rest without changing during arm elevation, and dynamic when it was evident only during arm elevation. Nerve conduction studies were performed in the standard fashion, using both needle and surface methodology for the LTN, and encompassed bilateral LTN and spinal accessory nerve evaluation, median and ulnar nerve study, and other nerves as clinically indicated. Additional testing, as warranted, included magnetic resonance imaging (MRI) of the cervical and thoracic spine, MRI of the scapula, genetic testing for facioscapulohumeral dystrophy, and blood work for autoimmune diseases, myopathy, and Lyme disease. Patients with sensorimotor polyneuropathy were excluded from this study. Statistical analysis comprised the Student t-test or Wilcoxon-Mann-Whitney test, with P < 0.05 considered significant.
Winged scapula was caused by LTN palsy (n = 70) most often, usually due to neuralgic amyotrophy (n = 61), with four resulting from stretch injury, two from brachial plexus radiotherapy, and one each due to surgery for breast cancer, lung cancer, or thoracic outlet syndrome. Serratus anterior muscle digitation atrophy was apparent in 20 of 38 male LTN palsy patients, and 77% of all LTN palsy patients demonstrated a rope-like lower trapezius muscle. Spinal accessory nerve palsy was the cause in 39 patients, either due to neck surgery (n = 13) or of medical origin (n = 26), the latter most often due to neuralgic amyotrophy (n = 20). Severe lower trapezius atrophy was seen in all instances due to spinal accessory nerve palsy, and severe upper trapezius atrophy was seen in most. Other causes of winged scapula included combined LTN and spinal accessory nerve palsy (n = 5), facioscapulohumeral dystrophy (n = 5), and orthopedic issues (n = 11), consisting of scoliosis, acromion exostosis, clavicular trauma, and rotator cuff impingement. In six cases, winging was voluntary, with the patient able to produce the winging on request on the healthy side as well. In two instances no cause was found. Winged scapula is most often due to LTN palsy from neuralgic amyotrophy. Careful examination can distinguish LTN from spinal accessory nerve palsy. In young patients, in addition to neuralgic amyotrophy, facioscapulohumeral dystrophy and traumatic causes should be considered.
COMMENTARY
Neuralgic amyotrophy, characterized by pain, weakness, and sensory loss, is rare in children. Between 2003 and 2017, 22 children 18 years of age or younger (14 boys and eight girls) were diagnosed with neuralgic amyotrophy at Boston Children’s Hospital. Pain was the presenting symptom in all, with periscapular weakness in 16 and scapular winging in 13. Persistent pain and weakness remained in more than 50% when seen in follow-up. Clinically, neuralgic amyotrophy in children is very similar to that seen in adults.1
REFERENCE
- Al-Ghamdi F, Ghosh PS. Neuralgic amyotrophy in children. Muscle Nerve 2018;57:932-936.
