Assistant Professor University of Minnesota Minneapolis, Minnesota, United States
Case Diagnosis: Dorsal scapular nerve (DSN) entrapment
Case Description: A 73-year-old male with a history of antiphospholipid syndrome on warfarin, left shoulder subacromial decompression, distal clavicle excision, and C5-C7 anterior cervical discectomy and fusion for left cervical radiculopathy presented with chronic left periscapular pain. The pain began in January 2020 without a clear cause. The pain, described as dull, aching, and burning, radiated from his trapezius to the latissimus dorsi and ribs. The pain was worse in the evenings. There were no aggravating or alleviating factors. Prior to arrival, the patient underwent multiple treatments including physical therapy, medications, and interventional procedures with no success. An electrodiagnostic work-up showed left dorsal scapular neuropathy. Extensive interventions were trialed involving the left DSN including a nerve block, radiofrequency ablation, bursa injection, peripheral nerve system implantation, and nerve hydrodissection with no pain relief. An MRI brachial plexus revealed hyperintense vascular malformation between the levator scapulae and rhomboid muscles. Further treatment discussions are ongoing.
Discussions: DSN entrapment is a rare cause of upper thoracic and interscapular pain. The DSN originates from the C5 nerve roots of the brachial plexus and innervates the levator scapulae and rhomboid muscles. Heavy lifting, repeated shoulder dislocations, and whiplash injuries are common causes for this condition. Symptoms include pain, tightness, dysesthesia, scapular atrophy, and scapula winging. Initial treatment typically includes conservative measures such as physical therapy and medications. Steroid injections and hydrodissections are also used. Surgical decompression of the DSN is considered when conservative management fails which can be a consideration for this patient.
Conclusions: DSN entrapment, though uncommon, should be considered in cases of upper thoracic pain and interscapular pain. Conservative treatment is usually sufficient, but surgical decompression may be necessary if these measures fail.
