Introduction Overview complex regional pain syndrome is defined as sustained sympathetic activity in a perpetuated reflex arc characterized by pain out of proportion to physical exam findings formerly known as reflex sympathetic dystrophy (RSD); many different names in past (remember "hand shoulder syndrome" as you will see this coexisting pathology) known as causalgia when associated with specific nerve Epidemiology incidence US incidence is 5.5 per 100,000 person-years demographics females more commonly affected (4:1) incidence increases with age up until 70 years old location 60% occurs in the upper extremities 40% occurs in the lower extremities risk factors trauma with an exagerrated response to injury most common reason for a poor outcome following a crush injury to the foot surgery prolonged immobilization anxiety or depression use of ACE inhibitors at the time of trauma history of migraines or asthma smoking Pathophysiology aberrant inflammatory response vasomotor dysfunction maladaptive neuroplasticity Genetics thought to have a genetic predisposition siblings of young-onset CRPS patients have an increased risk of developing CRPS associated with polymorphisms in TNF-alpha and ACE genes Prevention vitamin C 500mg daily x 50 days in distal radius fractures treated conservatively 200mg daily x 50 days if impaired renal function vitamin C also has been shown to decrease the incidence of CRPS (type I) following foot and ankle surgery avoid tight dressings and prolonged immobilization Prognosis typically responds poorly to conservative and surgical treatments better prognosis if upper extremity, warm CRPS, children Classification Lankford and Evans Stages of RSD Stage Onset Exam Imaging Acute 0-3 months Burning pain, redness, swelling, warmth, hyperhidrosis, hyperesthesia, cold intolerance, joint stiffness Normal x-rays, positive three-phase bone scan Subacute (dystrophic) 3-12 months Worsening pain, cyanosis, dry skin, stiffness, skin atrophy Subchondral osteopenia on x-ray Chronic (atrophic) > 12 months Diminished pain, glossy skin, fibrosis, joint contractures, loss of hair and nails Extreme osteopenia on x-ray International Association for the Study of Pain Classification type I CRPS without demonstrable nerve damage most common results from trauma, casting, or tight dressings type II CRPS with evidence of identifiable nerve damage minimal positive response with sympathetic blocks Presentation Cardinal signs exaggerated pain swelling stiffness skin discoloration Physical exam vasomotor disturbance trophic skin changes hyperhidrosis "flamingo gait" if the knee is involved equinovarus defomity if the ankle is involved Imaging Radiographs findings osteopenia affects the patella if the knee is involved soft tissue swelling subperiosteal bone resportion preservation of joint spaces Three-phase bone scan indications can help to rule out CRPS type I (has high negative predictive value) phases phase I (2 minutes) shows an extremity arteriogram phase II (5-10 minutes) shows cellulitis and synovial inflammation phase III (2-3 hours) shows bone images phase IV (24 hours) can differentiate osteomyelitis from adjacent cellulitis findings increased uptake in all phases phase III is most sensitive Thermography used to quantify temperature differences between the limbs questionable utility EMG/NCV may demonstrate slowing in known nerve distribution (e.g. slowing of median nerve conduction for CRPS type II in the forearm) Studies Diagnosis usually clinical but can be confirmed by pain relief with sympathetic block early diagnosis is critical for a successful outcome Budapest diagnostic criteria 1. Continuing pain that is disproportionate to any inciting event 2. Must report at least one symptom in three (clinical diagnostic criteria) or four (research diagnostic criteria) of the following categories: sensory: hyperesthesia or allodynia vasomotor: temperature asymmetry, skin colour changes, or skin colour asymmetry sudomotor/edema: edema, sweating changes, or sweating asymmetry motor/trophic: decreased range of motion, motor dysfunction (weakness, tremor, or dystonia), or trophic changes (hair, nails, or skin) 3. Must display at least one sign at time of diagnosis in two or more of the following categories: sensory: hyperalgesia (to pinprick) or allodynia (to light touch, deep somatic pressure, or joint movement) vasomotor: temperature asymmetry, skin colour changes or asymmetry sudomotor/edema: oedema, sweating changes, or sweating asymmetry motor/trophic: decreased range of motion, or motor dysfunction (weakness, tremor, or dystonia), or trophic changes (hair, nails, or skin) 4. No other diagnosis better explains the signs and symptoms Differential Soft tissue infection Malingering Psychiatric disease Neuropathic pain Chronic pain Raynaud disease Thoracic outlet syndrome Arterial insufficiency Erythromelalgia Treatment Nonoperative physical therapy and pharmacologic treatment indications first line of treatment nerve stimulation indications symptoms present mainly in the distribution of one major peripheral nerve nerve blockade indications failed initial nonoperative treatment chemical sympathectomy indications acts as another option when physical therapy and less aggressive nonoperative management fails Operative surgical sympathectomy indications failed nonoperative management (including chemical sympathectomy) surgical decompression indications CRPS type II with known nerve involvement (e.g. carpal tunnel release if median nerve involved) best success for CRPS is if you can find an associated nerve problem and treat it Techniques Physical therapy and pharmacologic treatment modalities gentle physiotherapy tactile discrimination training graded motor imagery sequential process consisting of laterality reconstruction, motor imagery, and mirror therapy medications NSAIDs alpha blockers (phenoxybenzamine, prazosin) beta blockers (propranolol) anti-depressants anti-convulsants calcium channel blockers GABA agonists (gabapentin) bisphosphonates anti-arrhythmics corticosteroids calcitonin Nerve stimulation programmable stimulators placed on affected nerves types transcutaneous electrical stimulation (TENS) peripheral nerve stimulation spinal cord stimulation Nerve blockade types sympathetic stellate ganglion (for upper extremity) lumbar spinal (for lower extremity) peripheral nerve neuraxial/epidural agents anesthetics (lidocaine or bupivicaine +/- epinephrine) sympatholytics (bretylium, guanethidine) Chemical sympathectomy types stellate ganglion (for upper extremity) lumbar spinal (for lower extremity) agents phenol alcohol Surgical sympathectomy ideal for patients who have had a response to sympathetic nerve blockade methods excision electrocautery
QUESTIONS 1 of 11 1 2 3 4 5 6 7 8 9 10 11 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ05.230) A 58-year-old female complains of continued pain and swelling 6 months following total knee arthroplasty. She describes a burning pain that radiates from the knee down the anterior compartment of the leg. The pain arises sporadically and is associated with swelling, sweating, and a purplish hue of the leg. Knee radiographs are provided in Figures A and B. Aspiration is negative for infection. Which of the following is the best management? Review Topic QID: 1116 FIGURES: A B 1 Lumbar spine MRI to evaluate for radiculopathy of the L3 nerve root 2% (19/839) 2 Alpha-adrenergic blockers, physical therapy, tactile discrimination training, and graded motor imagery 93% (777/839) 3 Surgical exploration of the knee 1% (7/839) 4 Surgical debridement, pulsatile irrigation, tissue sampling for culture/biopsy, and polyethylene exchange 3% (22/839) 5 Magnetic resonance arthrogram (MRA) with intra-articular contrast and diagnostic steroid injection 1% (11/839) ML 1 Select Answer to see Preferred Response PREFERRED RESPONSE 2 (OBQ10.253) Level 1 evidence has shown vitamin C reduces the incidence of reflex sympathetic dystrophy (RSD) or complex regional pain syndrome type I (CRPS) in patients with which of the following? Review Topic QID: 3356 1 Tarsal tunnel syndrome 0% (9/2899) 2 Distal radius fractures 91% (2649/2899) 3 Carpal tunnel syndrome 4% (107/2899) 4 Cervical radiculopathy from herniated nucleus pulposis 1% (35/2899) 5 Ankle fractures 3% (86/2899) ML 1 Select Answer to see Preferred Response PREFERRED RESPONSE 2 (OBQ13.176) Vitamin C has been shown to decrease the likelihood of which of the following complications following surgery on the foot and ankle in non-diabetic patients? Review Topic QID: 4811 1 Nonunion 1% (38/3813) 2 Complex Regional Pain Syndrome, type II 15% (572/3813) 3 Malunion 0% (14/3813) 4 Complex Regional Pain Syndrome, type I 79% (3006/3813) 5 Wound infection 4% (160/3813) ML 2 Select Answer to see Preferred Response PREFERRED RESPONSE 4 (OBQ04.43) A 34-year-old laborer has her left foot crushed in a piece of farming equipment as shown in Figure A. All of the following are reasons for a poor outcome following a crush injury to the foot EXCEPT: Review Topic QID: 104 FIGURES: A 1 Workers compensation injury 2% (7/395) 2 Development of reflex sympathetic dystrophy (complex regional pain syndrome) 1% (4/395) 3 Delayed soft-tissue coverage in mangled extremities 10% (40/395) 4 Immediate skeletal stabilization 85% (335/395) 5 Ongoing litigation 2% (9/395) ML 1 Select Answer to see Preferred Response PREFERRED RESPONSE 4 (OBQ06.29) A 52-year-old woman falls stepping off the escalator and sustains the wrist fracture shown in Figures A and B. Post-reduction radiographs demonstrate 20 degrees of residual dorsal angulation. The decision is made to proceed with open reduction internal fixation with a volar plate. Which of the following adjuvant interventions has studies in the literature to support an improvement in outcomes? Review Topic QID: 140 FIGURES: A B 1 Application of a bone stimulator within one week following surgery 3% (44/1680) 2 Supplemental percutaneous pin fixation that is removed 4 weeks following surgery 3% (50/1680) 3 Immobilization of the wrist in an extension splint or cast for 3 weeks following surgery 6% (106/1680) 4 Administration of oral vitamin C beginning the first day after surgery 85% (1420/1680) 5 Use of an axillary regional block during the surgery 3% (54/1680) ML 1 Select Answer to see Preferred Response PREFERRED RESPONSE 4 (OBQ05.269) A 38-year-old patient presents 6 months after intramedullary nailing of a distal third tibia fracture with symptoms consistent with complex regional pain syndrome. During the early stage of the disease he was treated with intermittent splinting, elevation and massage, contrast baths, and transcutaneous electrical nerve stimulation. Despite these modalities, he continues to have severe and debilitating symptoms. Which of the following treatment options is indicated as a second line of treatment? Review Topic QID: 1155 1 Long leg cast immobilization for 3 months 3% (18/650) 2 Walking boot with non weight bearing for three months 4% (29/650) 3 Exchange nailing to stimulate healing response to the limb 5% (32/650) 4 Epidural spinal cord stimulator 19% (123/650) 5 Surgical sympathectomy of the affected limb 68% (442/650) ML 3 Select Answer to see Preferred Response PREFERRED RESPONSE 5 (OBQ07.202) Which of the following modalities has been shown to have a positive effect when treating early stages of complex regional pain syndrome? Review Topic QID: 863 1 Casting of the involved extremity 19% (315/1699) 2 Plyometric exercises 4% (63/1699) 3 Ultrasound therapy 4% (74/1699) 4 Acupuncture 4% (67/1699) 5 Gentle physiotherapy 69% (1174/1699) ML 3 Select Answer to see Preferred Response PREFERRED RESPONSE 5 (OBQ05.139) All of the following are clinical features of complex regional pain syndrome (reflex sympathetic dystrophy) of the lower extremity EXCEPT: Review Topic QID: 1025 1 Swelling 1% (21/2125) 2 Cool and shiny skin 2% (38/2125) 3 Allodynia 1% (19/2125) 4 Crepitus 95% (2017/2125) 5 Hyperpathia 1% (23/2125) ML 1 Select Answer to see Preferred Response PREFERRED RESPONSE 4 (OBQ04.191) What is the most common radiographic finding in reflex sympathetic dystrophy (RSD) or complex regional pain syndrome of the knee? Review Topic QID: 1296 1 patella baja 2% (6/374) 2 patella alta 5% (17/374) 3 patella osteopenia 43% (161/374) 4 generalized osteopenia 50% (186/374) 5 supracondylar stress fracture 1% (2/374) ML 4 Select Answer to see Preferred Response PREFERRED RESPONSE 3