MM-657 Parsonage Turner Syndrome Complicating Multiple Myeloma Therapy: “Nothing to Shrug your Shoulders at”

• Published in: Clinical lymphoma, myeloma and leukemia Vol. 24; p. S578
• Main Authors: Popat, Dhara, Sanghavi, Nairuti, Singh, Ashmin, Sawhney, Rishi
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.09.2024
• Subjects: Bortezomib; Brachial plexitis; Multiple myeloma; Parsonage turner; MM; Parsonage turner; Bortezomib; Brachial plexitis; case; Multiple myeloma
• ISSN: 2152-2650
• DOI: 10.1016/S2152-2650(24)01720-8

Parsonage turner (PTS) is a rare syndrome characterised by rapidly progressive bilateral plexopathy. It has commonly been associated with post-viral infection or postvaccination etiologies but very few drug related cases have been reported. We present a case of the syndrome in a patient with multiple myeloma treated with Bortezomib, Lenalidomide and Dexamethasone. A 66-year-old man was diagnosed with multiple myeloma based on bone marrow biopsy results. He was started on standard treatment with bortezomib, lenalidomide, and dexamethasone. After the 4 th cycle, he achieved excellent partial response to treatment but developed acute bilateral shoulder pain followed by severe bilateral arm weakness wherein he could not lift his arms against gravity. He had no sensory deficits. Inflammatory markers were within normal limits. MRI of brain and cervical spine could not be performed due to an incompatible pacemaker. EMG findings included severe acute denervation of the deltoids. The clinical signs and EMG findings confirmed the diagnosis of PTS. His symptoms were managed with physical therapy as he was out of the window for fruitful management with IVIG or steroids. PTS is a brachial plexitis and presents with acute pain followed several days to weeks later by weakness of muscles innervated by the brachial plexus. The incidence is approximately 1.64 to 3.00 per 100,000 individuals. The aetiology is genetic mutation mediated or idiopathic/immune mediated. Treatment of choice is analgesics and physical therapy. Some cases have shown benefit with early phase pulse dose steroids and IVIG. There have been multiple case reports of PTS post-infections such as COVID 19, HIV, CMV, Borrelia as well as post vaccination. Drug related aetiology is uncommon. Two cases of PTS have been noted in patients who received Bortezomib in combination with other cancer treatment modalities. This is unlike the usual peripheral sensory neuropathy seen with Bortezomib. Bilateral presentation of Parsonage turner syndrome as seen in our patient has also not been commonly reported. It is imperative to monitor patients being initiated on Bortezomib for brachial plexopathy and study the immune mechanisms and genetic mutations leading to the same.