(287) Interscalene Brachial Plexus Block with Dexamethasone for Treatment of Parsonage-Turner Syndrome

Abstract

CD is an 83y M with a history of COPD, non-Hodgkin lymphoma, and lung CA who presented with acute onset non-dermatomal left arm pain. The patient had developed a viral infection 2 weeks prior, and soon after developed left shoulder and arm pain. Imaging and labs did not show rheumatologic, infectious, or cervical nerve cause, however EMG was consistent with brachial plexopathy. A presumptive diagnosis of Parsonage-Turner syndrome was made, and conservative measures were initiated. Unfortunately, the patient did not note improvement with medications, PT, or TENS unit. He was then scheduled for an ultrasound-guided interscalene brachial plexus nerve block with Bupivacaine and Dexamethasone. After the injection, the patient noted > 50% improvement in pain and was able to better participate in physical therapy and significantly increased functionality of his upper extremity. Parsonage-Turner syndrome is a rare autoimmune neuropathy of the brachial plexus, most commonly affecting the upper trunk. It is idiopathic in nature, however may be linked to a post-infectious or post-immunization process. It often presents as acute onset neck, shoulder and arm pain which can progress to weakness, and may often be confused with cervical radiculopathy or thoracic outlet syndrome. Common physical exam features include a slight winging of the scapula, as well as the potential for motor weakness and loss of sensation that does not follow a dermatomal pattern. Imaging, including CT/MRI or plain film, is not always helpful in diagnosis. However, electrodiagnostic testing such as EMG can usually localize the defect to the root level. Conservative therapies are the gold standard for treatment, however some evidence points to improvement with systemic steroids. We believe targeted steroid injections can be an effective therapy for Parsonage Turner Syndrome.