Description

A 30-year-old male presented with a 15-year history of proximal weakness and decreased temperature sensation in both upper limbs. There was no history to suggest a hereditary connective tissue disorder, and no prior trauma. On examination, he had lateral winging of the scapula (WOS) with the superior angle displaced laterally (figure 1), mild weakness of bilateral upper extremities, reduced pain and temperature sensation in dermatomes C2 to T3, and normal proprioception, while tendon reflexes were absent in the upper limbs and brisk in the lower limbs, and plantars were extensor. MRI of the spine revealed a large syrinx with an Arnold–Chiari malformation (ACM) type 1 (figure 2). X-rays of the craniovertebral junction did not reveal occipitoatlantoaxial hypermobility.

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Figure 1

Photograph of the patient showing lateral winging of both scapulae with the superior angle (black arrows) displaced laterally as compared to the inferior angle (white arrows) suggestive of trapezius weakness.

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Figure 2

T2 weighted sagittal images showing mild tonsillar descent (thin arrow) below the foramen magnum suggestive of Arnold–Chiari malformation type 1. In addition, syringomyelia (thick arrow) extending from segment C1 into the thoracic spinal cord is seen.

WOS is a condition where the medial border of the scapula is prominent due to weakness of the serratus anterior, trapezius or rhomboid muscles.1 Weakness of the serratus anterior leads to medial winging (the medial border lies more medially), whereas weakness of the trapezius or rhomboids leads to lateral winging (the medial border lies laterally).1 This shift is due to the unopposed action of normal muscles. In trapezius weakness, the scapula is rotated such that the superior angle is laterally displaced, whereas in rhomboid weakness, the inferior angle is laterally displaced.1 In our patient, ACM type 1 with syringomyelia led to trapezius weakness and lateral WOS, an association that has been infrequently reported.2 ,3 He underwent posterior fossa decompression with duroplasty, and on follow up 6 months later, his neurological examination remained unchanged.