Subcutaneous Botulinum Toxin A for the Treatment of Refractory Complex Regional Pain Syndrome

Abstract

Complex regional pain syndrome (CRPS) is a chronic neuropathic pain condition of unclear etiology that can be very difficult to treat. Typically, CRPS affects the extremities, although it can affect any area of the body [1]. In 2010, the Budapest criteria for the clinical diagnosis of CRPS were established as an update to the more nonspecific criteria originally given in 1994 [2]. Currently, to meet the diagnosis of CRPS, a patient must present with the following conditions: 1. Continuing pain that is disproportionate to any inciting event. 2. At least one symptom reported in 3 of the 4 following categories: a. Sensory: reports of allodynia and/or hyperesthesia type symptoms. b. Vasomotor: temperature asymmetry and/or skin color changes. c. Sudomotor/edema: edema and/or sweating changes/asymmetry. d. Motor/trophic: decreased range of motion and/or motor dysfunction (weakness, tremor, dystonia) and/or trophic changes (hair, nail, skin). 3. At least one sign at the time of evaluation in 2 or more of the following categories: a. Sensory: hyperalgesia to pinprick and/or allodynia to light touch (or deep somatic pressure or joint movement). b. Vasomotor: temperature asymmetry and/or skin color changes (or asymmetry). c. Sudomotor and/or edema: edema and/or sweating changes (or asymmetry). d. Motor and/or trophic: decreased range of motion and/or motor dysfunction (weakness, tremor, dystonia) and/or trophic changes (hair, nail, skin).