A medical mystery of complex regional pain syndrome

Abstract

Complex regional pain syndrome (CRPS) is a condition of neuropathic pain, which is characterized by significant autonomic and inflammatory features. CRPS occurs in patients who have limb surgery, limb fractures, or trauma. Many patients may have pain resolve within twelve months of the inciting incident; however, a small subset progresses to the chronic form. This transitional process often happens by changing from warm CRPS with dominant inflammatory phase to cold CRPS, in which autonomic characteristics or manifestations dominate. Several peripheral and central mechanisms are involved, which might vary among individuals over a period of time. Other contributors include peripheral and central sensitization, autonomic alterations, inflammatory and immune changes, neurochemical changes, and psychological and genetic factors. Although effective management of the chronic CRPS form is often challenging, there are a few high quality randomized controlled trials that support the efficacy of the most commonly used therapeutic approaches.

Complex Regional Pain Syndrome Caused by an Axillary Lipoma

“…Although most cases tend to resolve within a year following the inciting trauma, some cases progress to a more severe, chronic form of the condition [ 10 ]. Development of post-surgical CRPS is not uncommon; however, little is known regarding predisposing risk-factors to surgical candidates for CRPS [ 11 ].…”

Intramuscular Injection and Complex Regional Pain Syndrome Development After “Harmless” Procedures

“…Sympathetic activation can manifest in color change, temperature change, as well as hyper-and hypohidrosis. Autonomic changes differ in warm and cold stages of the condition [4,7]. First, initial norepinephrine release wanes, leading to increased blood flow.…”

“…Common examples include physical therapy, neuropathic pain medication, anti-inflammatories, bisphosphonates, sympathetic nerve blocks, and direct neural stimulation [4,17]. Sympathetic blocks are often insufficient for most patients, and epidural clonidine may reveal adverse effects in addition to benefits [7]. Immunoglobulin infusion clinical trials were not found to be effective in CRPS management, bringing the autoimmune aspect of the disease into question [18].…”

“…They have also demonstrated increased inter-rater reliability between physicians [ 3 - 6 ]. However, no test is considered by all to be the “Gold Standard” in the diagnosis of CRPS [ 5 - 7 ]. More than 50,000 cases of CRPS are diagnosed per year, and it is assumed that many more are missed because physicians are not familiar with its presentation [ 8 ].…”

Editorial: Mechanisms and New Targets for the Treatment of Chronic Pain

“…described that the local administration of TRPV1 antagonist had analgesic effects on pain hypersensitivity associated to a rat model of complex regional pain syndrome (CRPS) induced by ischemia. This study suggests that TRPV1 channel might have an important role on this pain syndrome, whose pathophysiology remain poorly understood ( Eldufani et al., 2020 ). Idris et al.…”