AB241. Ultrasound-guided dorsal scapular nerve blockade in the diagnosis and management of middle scalene muscle-related myofascial pain

Background: We report the first description of ultrasound-guided dorsal scapular nerve blockade using single shot local anaesthetic technique, for the diagnosis and treatment of myofascial pain affecting the middle scalene muscle. Although ultrasound imaging of Dorsal Scapular Nerve (DSN) has been previously described, we believe this is the first report of ultrasound guided blockade of this nerve for neck pain.

Methods: A 38-year-old female patient presented with neck pain. There was interscapular pain on the right side. On examination there was limitation in range of movement due to pain. There was anterior neck tenderness on the right side. Neurological exam was normal. A high frequency ultrasound transducer was used. The dorsal scapular nerve was located in the anterior scalene muscle. Local anaesthetic and steroid was deposited around the nerve.

Results: The patient reported persistent pain relief six weeks later.

Conclusions: We hope to highlight the importance of Dorsal Scapular Nerve entrapment as an important contributor of neck and interscapular pain. The use of peripheral nerve block in the treatment of neck pain may help to extend our understanding of pain of unknown etiology and aid in the diagnosis which is crucial. Unfortunately, this approach has been limited by the fact that there is a greater focus on proximal spinal structures (joints, discs and nerve roots). As a result, peripheral musculature has been largely ignored as a possible source of pain. Selectively blocking a peripheral motor nerve can relax a specific muscle or a group of muscles which can help alleviate the pain. Once an accurate diagnosis is made as to the specific muscle as a cause then subsequent treatments can be more focused leading to better outcomes. Our technique can therefore be used to help diagnose neck pain originating from DSN

Keywords: Dorsal scapular nerve; ultrasound; neck pain; interscapular pain; middle scalene muscle; diagnosis