Refractory Complex Regional Pain Syndrome: A Case Report and Review of Literature.

Introduction: Complex regional pain syndrome (CRPS) is characterized by extreme pain in a limb disproportional to the clinical history or physical findings accompanied by the signs of autonomic dysfunction. The pathophysiology of CRPS is obscure, making it challenging to treat. Treatment options include medications, physical therapy, and psychological support. In some cases, surgery or other minimally-invasive procedures such as nerve blocks may be recommended, while several novel treatments, such as ozone therapy, lack sufficient clinical evidence. Case Presentation: A 40-year-old man with CRPS was referred to our clinic with pain in his right arm and left lower leg. The patient had a history of trauma to the ulnar nerve and had undergone a sural to ulnar nerve autograft surgery. After the surgery, the patient's symptoms began, primarily in the right arm. Despite receiving conventional drugs, multiple nerve blocks, and lidocaine patches, the patient's symptoms persisted. In addition, we tried medical ozone for 14 sessions along with ketamine infusion, but these treatments were also ineffective. Conclusions: We emphasize the importance of studying and developing more effective treatments for CRPS and suggest that further randomized clinical trials are needed to determine whether ozone therapy is effective for patients with severe, intractable CRPS symptoms.