MSK-28 · Complex Regional Pain Syndrome and Myofascial Pain

Complex Regional Pain Syndrome and Myofascial Pain. Part of the Musculoskeletal series of the Reflex PM&R Board Review podcast. Audio corrections: (1) In the audio: The four categories are sensory, which includes hyperesthesia or allodynia. — Correct: The sensory category of the Budapest criteria is hyperalgesia and/or allodynia. Hyperalgesia is an exaggerated pain response to an already painful stimulus such as pinprick; hyperesthesia is a different word meaning heightened sensitivity to any stimulus, and the criteria do not use it. (2) In the audio: For the upper extremity, the stellate ganglion block targets C7 anteriorly. — Correct: The ganglion lies anterolateral to the C7 vertebral body at C7 to T1, but the needle is placed at the Chassaignac tubercle, the anterior tubercle of the C6 transverse process, to stay clear of the vertebral artery and the pleural dome. (3) In the audio: Significant pain relief means the pain is sympathetically maintained. — Correct: That labels the pain but does not diagnose CRPS. A positive block response does not confirm the diagnosis and a negative one does not exclude it; current guidelines treat the block as an empiric therapeutic trial, and CRPS remains a clinical diagnosis made against the Budapest criteria. (4) In the audio: It affects women three times as often as men, and the incidence peaks in the fifth through seventh decades of life. — Correct: Roughly three to four times as often as men, and there is no single narrow peak in onset age. One population study found a median onset in the mid-40s and a larger one found the highest incidence in postmenopausal women in their 60s. (5) In the audio: or up to 100 to 200 milligrams a day, tapered over roughly two weeks. — Correct: The high-dose convention is not supported for early CRPS. The controlled trial regimen was about 30 mg of prednisone daily continued until remission, and guidelines synthesize this as approximately 30 mg per day for 2 to 12 weeks with a taper; the one high-dose trial studied longstanding, treatment-resistant disease and was negative. (6) In the audio: It's cheap, safe, and highly effective. — Correct: Vitamin C 500 mg daily for 50 days is the regimen the trials used and stays the board answer, but the evidence is mixed: a later large randomized trial at the same dose found no benefit, and the orthopaedic guideline dropped the topic in its 2020 update. (7) In the audio: the intravenous route reduces pain and improves function in CRPS. And this actually has strong randomized data behind it, — Correct: The randomized data are low certainty and the benefit is short-term pain only. The largest synthesis (11 trials, 754 patients) finds bisphosphonates may reduce pain in the short term by about 10 points on a 0 to 100 scale at low certainty, with little to no difference at 3 to 6 months or beyond, and probably more adverse events. Improved function is not supported. They are an adjunct, not a mainstay. The written chapter is correct. Full correction register: https://www.reflexpmr.com/errata. The full companion chapter and a linked board-style Q-bank set for this topic are at https://www.reflexpmr.com/read/MSK-28.