Atypical Electrodiagnostic Findings in Scapular Winging Secondary to Multiple Neuropathies: A Case Series

Mitul Kapadia MD, MS3, Oluseum Olufade MD2, Gilbert Siu DO PhD2, Theera Vachranukunkiet, MD1, C.R. Sridhara MD1,2,3 1MossRehab, Elkins Park, PA, 2Temple University Hospital, Philadelphia, PA

3Jefferson University Hospital, Philadelphia, PA

ABSTRACTSetting: Electrodiagnostic laboratory at tertiary care rehabilitation centerPatients: Four patients, two males and two females, with mean age of 46 years (range 21-68 years) with scapular winging. Background: Scapular winging is an easily diagnosed condition seen by visible inspection. Causes of scapular winging usually involve one nerve (long thoracic, spinal accessory or dorsal scapular nerve), resulting in either lateral or medial scapular winging. We present a series of four patients for electrodiagnostic evaluation with atypical scapular winging. Assessment & Results: One patient presented with right shoulder pain after a flu-like illness and electrodiagnostic studies revealed an axon-loss neuropathy involving the right upper and middle spinal accessory nerve branches and dorsal scapular nerve. The second patient presented with right arm weakness after a fall with a traumatic brain injury and was found to have isolated neurapraxic block with preservation of axons involving the upper and lower spinal accessory nerve branches and long thoracic nerve. The third patient presented with right arm weakness and pain after thyroidectomy and was found to have axon-loss neuropathy involving the upper and middle spinal accessory nerve branches and long thoracic nerve. The fourth patient presented with right shoulder weakness after a fall/injury and was found to have axon-loss neuropathy involving the all three branches of spinal accessory nerve, long thoracic nerve and a C5 radiculopathy. Discussion: Unilateral scapular winging with similar clinical presentation can result from various neuropathic etiologies. Electrodiagnostic findings in these four cases revealed multiple neuropathies involving two or three nerves that cause winging of the scapula. Etiology in two of the four patients was trauma, one patient with Parsonage Turner Syndrome and one patient due to surgery related to carcinoma. Conclusions: Although uncommon, this case series provides examples of multiple nerve involvement in scapular winging and the importance of electrodiagnostic studies for evaluating involvement of the specific nerves.Keywords: Scapula winging; Dorsal scapular neuropathy; Spinal accessory neuropathy; Long thoracic neuropathy

CASE SERIES DESCRIPTIONThe first patient is a 68 year-old female with a history of a traumatic brain injury who presented with severe right shoulder pain shortly after having an acute flu-like respiratory infection. Physical examination revealed marked atrophy of the right shoulder girdle with medial winging of the scapula at rest with glenoid depression or clockwise rotation (Figure 1).  The second patient is a 36 year-old male who presented with right arm weakness after a fall down a number of stairs that resulted in a traumatic brain injury. Physical examination revealed atrophy of his right shoulder girdle muscles. The right scapula was depressed and laterally rotated with medial winging exacerbated with forward flexion (Figure 2). Muscle strength was diminished in the right upper and lower trapezius and serratus anterior.  The third patient is a 21year-old male who presented with right upper arm weakness and pain following a total thyroidectomy for multifocal papillary thyroid cancer. Subsequently, the patient underwent right extended comprehensive cervical lymphadenectomy. Physical examination revealed right scapular winging both with activation of the serratus anterior and the middle trapezius. Muscle strength was diminished in the right serratus anterior and trapezius.  The fourth patient is a 60 year old female who presented with right shoulder weakness and pain after a fall in which she fell on her outstretched right hand while she had heavy books with her and also another local trauma to shoulder. Physical examination revealed significant depression of the right scapula, winging of the right scapula with the inferior angle more medial than the glenoid, and atrophy of all sections of the trapezius. She had decreased strength on manual muscle testing of all sections of the right trapezius (upper, middle, and lower) along with the serratus anterior.

DISCUSSION

CONCLUSION

REFERENCES

Even though scapular winging involving a single nerve is a rare debilitating condition, having multiple nerves involved is uncommon and atypical with need for complex rehabilitation planning. This case series highlights the importance of electrodiagnostic studies for evaluating multiple specific nerves involved in scapular winging that would generally have been overlooked.

1. Martin RM, Fish DE. Scapular winging: anatomical review, diagnosis, and treatment. . Curr Rev Musculoskelet Med. 2008 Mar;1(1):1-11.2. Schreiber AL, Abramov R, Fried GW, Herbison GJ. Expanding the differential of shoulder pain: Parsonage-Turner syndrome. J Am

Osteopath Assoc. 2009 Aug;109(8):415-22.3. Akgun K, Aktas I, Terzi Y. Winged scapula caused by a dorsal scapular nerve lesion: a case report. Arch Phys Med Rehabil. 2008

Oct;89(10):2017-20.4. Wiater JM, Bigliani LU. Spinal accessory nerve injury. Clin Orthop Relat Res. 1999 Nov;(368):5-16.

Most cases of scapular winging described in the literature results in neuropathy of single nerve, most commonly the long thoracic nerve, and have a clearly discernable presentation. However, scapular winging due to multiple nerve and muscle involvement is rarely reported. In this study, we present a series of cases of unilateral scapular winging which presented with indistinct presentations. The initial cause of scapular winging in these cases was either trauma, remote trauma with possible Parsonage Turner Syndrome or surgery related to carcinoma. Physical examination findings varied in each patient, but proved inconclusive in elucidating the precise neuropathic etiology. Although a scapular winging is a clinical diagnosis, the electrodiagnostic evaluation helped to clarify the unusual multiple neuropathies involved in the atypical presentations of these cases. The neuropathies in each of these cases involved two or three nerves varying from spinal accessory nerve branches, dorsal scapular nerve, long thoracic nerve and C5 radiculopathy. These multiple neuropathies lead to weakness in multiple scapular muscles and disruption of scapular motion (Figure 3). It is this multiple nerve etiology of the scapular winging that led to indistinguishable presentations and illustrates precisely the value of electrodiagnostic evaluation in discerning etiology of scapular winging.

Without electrodiagnostic verification of these scapular winging cases, successful rehabilitation and treatment for scapular winging would have been difficult due to the multiple nerves involved. Therefore, in these patients, rehabilitation was prescribed to target at least two muscle groups with scapular stabilization.

EMG Table Spontaneous MUAP Recruitment

IA H.F. Dur. PPP Pattern

R. Rhomboid Maj C5

N None 1+ 2+ Mild Red

R. Serr Ant C5, 6,7

N None N N Mild Red

R. Trapezius (M) C3, 4

N CRD's N 2+ N

Nerve / Sites Rec. Site Lat Amp Rel Amp Area

ms mV % mVms

R Spinal Accessory - Trapezius

1. Neck Upper Trap 3.05 1.7 100 6.5

2. Neck Mid Trap 4.25 0.4 20.9 1.1

3. Neck Lower Trap 7.00 2.3 134 16.8

L Spinal Accessory - Trapezius

1. Neck Upper Trap 2.70 6.5 100 51.3

2. Neck Mid Trap 3.30 4.8 74 27.4

3. Neck Lower Trap 5.55 2.7 42.2 19.8

L Long Thoracic - Upper Ext

1. Neck Thorax 2.85 1.0 2.1

R Long Thoracic - Upper Ext

1. Neck Thorax 3.10 1.2 1.9

Nerve / Sites Rec. Site Lat Amp Rel Amp Areams mV % mVms

L Spinal Accessory - Trapezius Neck (X1 - X2) Upper Trap 2.25 11.4 100 92.6 Neck (X3 - X4) Mid Trap 2.75 6.7 58.8 48.5 Neck (X5 - X6) Lower Trap 5.15 2.5 21.9 16.8R Spinal Accessory - Trapezius Neck (X1 - X2) Upper Trap 2.05 6.3 100 48.9 Neck (X3 - X4) Mid Trap 2.10 7.8 124 66.9 Neck (X5 - X6) Lower Trap 3.30 0.3 4.88 0.8

Nerve / Sites Rec. Site Resp Lat Amp Rel Amp Areams mV % mVms

L Long Thoracic - Serratus AntNeck Ser Ant 4.70 2.0 100 20.8

R Long Thoracic - Serratus AntNeck Ser Ant No 4.00 0.1 100 2.6

Patient #1. Pertinent electrodiagnostic results showing axon-loss neuropathy involving the right upper and middle spinal accessory nerve branches and dorsal scapular nerve .

EMG Table

Spontaneous

MUAP Recruitment

IA Dur. PPP Pattern

R. Rhomboid Maj C5

N N N N

R. Serr Ant C5, 6,7

N N N N

R. Trapezius (M) C3, 4

N N N N

EMG Table

Spontaneous MUAP Recruitment

IA Fib PSW Dur. PPP Pattern

R. Serr Ant C5,6,7

Increase 1+ 1+ N N Mild Red

R. Trapezius (U) C3,4

Increase 2+ 3+ N N Discrete

R. Trapezius (M) C3,4

Increase 1+ 1+ N N Discrete

R. Trapezius (L) C3,4

Increase 1+ 1+ N N Mod Red

R. Deltoid C5,6

N None None N N N

Nerve / Sites Rec. Site Lat Amp Rel Amp Areams mV % mVms

R Spinal Accessory - Trapezius (3 Ch)1. Neck Upper Trap 1.65 1.1 100 11.92. Neck Mid Trap 2.05 2.1 181 19.33. Neck Lower Trap 3.40 1.7 147 16.7L Spinal Accessory - Trapezius (3 Ch)1. Neck Upper Trap 1.90 10.4 100 65.92. Neck Mid Trap 2.30 10.2 98.6 66.53. Neck Lower Trap 3.35 2.6 25.4 12.2L Long Thoracic - Upper Ext1. Neck Ser Ant 3.45 4.9 100 45.5R Long Thoracic - Upper Ext1. Neck Ser Ant 4.15 1.2 100 5.0

EMG Table Spon MUAP Recruitment

IA AMP Dur PPP Pattern

R. Serr Ant C5,6,7 N N 1+ 2+ Discrete

R. Deltoid C5,6 N N N 1+ N

R. Trapezius (U) C3,4 N N N 1+ Mod Red

R. Trapezius (L) C3,4 N 1-/N 1-/N 1+ Mild Red

R. SCM N 1-/N 1-/N 1+ Mild Red

Nerve / Sites Rec. Site Lat Amp Rel Amp Areams mV % mVms

R Spinal Accessory - Trapezius (3 Ch)1. Neck Upper Trap 2.25 1.0 100 7.32. Neck Mid Trap 3.50 0.5 51.2 3.03. Neck Lower Trap 4.40 1.5 148 5.1L Spinal Accessory - Trapezius (3 Ch)1. Neck Upper Trap 1.70 6.4 100 50.82. Neck Mid Trap 2.90 7.5 117 51.73. Neck Lower Trap 3.55 5.8 90.9 39.6L Long Thoracic - Upper Ext1. Neck Ser Ant 4.45 3.2 100 20.6R Long Thoracic - Upper Ext1. Neck Ser Ant 4.15 1.3 100 10.7

Patient #2. Pertinent electrodiagnostic results showing right isolated neurapraxic block with preservation of axons involving the upper and lower spinal accessory nerve branches and long thoracic nerve.

Patient #4. Pertinent electrodiagnostic results showing right axon-loss neuropathy involving the all three branches of spinal accessory nerve, long thoracic nerves and a C5 radiculopathy.

Patient #3. Pertinent electrodiagnostic results showing right axon-loss neuropathy involving the upper and middle spinal accessory nerve branches and long thoracic nerve..

Figure 3. A schematic diagram of the scapula demonstrating different muscle involvements in scapular winging.

Figure 1 Figure 2