Reflex sympathetic dystrophy (Sudeck’s atrophy)

Question 1

Summary

Answer 1

Complex Regional Pain Syndrome previously known as Reflex Sympathetic Dystrophy and Sudeck’s Atrophy, it is a complex pain syndrome triggered by an aberrant inflammatory response that leads to sustained sympathetic activity in a perpetuated reflex arc

Pain symptoms seem to be extreme and out of proportion to physical exam findings

They are idiopathic in nature

Dx via Budapest Dx criteria and can be confirmed with sympathetic block causing pain relief

Tx is usually physical therapy, pain meds, nerve stim or nerve blockade. Surgical sympathectomy indicated in cases of progressive pain that fails nonop management

Question 2

Epidemiology

Answer 2

• Females more commonly affected
• Incidence increases with age up to 70
• More common in upper extremity

Risk Factors for developing CRPS:
- Trauma with exagerrated response to injury
- Surgery [especially foot or ankle related]
- Prolonged immobilization
- Smoking
- History of migraines and asthma
- Fibromyalgia

Question 3

Etiology

Answer 3

Pathophysio:
- Aberrant Inflammatory Response
- Vasomotor Dysfunction
- Maladaptive Neuroplasticity

Genetics:
- Some link to genetics is present
- Siblings of young onset CRPS have increased risk of developing CRPS
- Associated with TNFalpha and ACE gene polymorphisms

Prevention:
- VIT C shown to decrease incidence of CRPS Type 1 following foot and ankle surgery

Question 4

Classification

Answer 4

Lankford and Evans Stages of RSD
- ACUTE: 0-3 months | Burning pain, redness, warmth, hyperhidrosis, hyperesthesia, cold intolerance, joint stiffness | Normal Xrays, postivite three-phase bone scan
- SUBACUTE: 3-12 months | Worsening pain, cyanosis, dry skin, stiffness, skin atrophy | Subchondral osteopenia on xray
- CHRONIC: > 12 months | Diminished pain, glossy skin, fibrosis, joint contractures, loss of hair and nails | Extreme osteopenia on xray

International Association for Study of Pain Classification:
- TYPE 1: CRPS without demonstrable nerve damage [most common]
- TYPE 2: CRPS with evidence of identifiable nerve damage

Think of Lankford and Evans classification as progressive reduction in blood supply, affecting vasomotor aka sympa affects on the supplied tissues

Question 5

Presentation

Answer 5

Cardinal Signs:
- Exaggerated Pain
- Swelling
- Stiffness
- Skin discolouration

Physical Exam:
- Vasomotor disturbance
- Trophic skin changes
- Hyperhidrosis
- “Flamingo gait” if knee is involved
- Equinovarus deformity if ankle is involved

Question 6

Imaging

Answer 6

Radiographs:
- Osteopenia [patellar involvement if knee is affected]
- Soft tissue swelling
- Subperiosteal bone resorption
- Preserved joint spaces

Three-phase Bone scan:
- Rule out CRPS type 1
- Increased uptake in all phases [Phase 3 most sensitive, shows bone images]

Question 7

Studies

Answer 7

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

Question 8

Differential

Answer 8

• Soft tissue infection
• Malingering
• Psychiatric disease (e.g. Clenched Fist Syndrome)
• Neuropathic pain
• Chronic pain
• Raynaud disease
• Thoracic outlet syndrome
• Arterial insufficiency
• Erythromelalgia

Question 9

Treatment

Answer 9

Physical Therapy and Pharmacological intervention:
- Gentle physiotherapy
- Tactile discrimination training
- Graded motor imagery
- NSAIDS
- Alpha blockers
- Beta blockers
- Antidepressants/convulsants
- CCBs
- GABA agonists

Nerve Stimulation:
- Programmable stimulators placed on affected nerves
- Transcutaneous electrical stimulation
- Peripheral nerve stimulation
- Spinal cord stimulation

Nerve Blockade:
- Stellate ganglion [upper limbs]
- Lumbar spinal [lower limbs]
- Peripheral nerve
- Neuraxial/epidural
- Agents: anaesthetics, sympatholytics

Chemical Sympathectomy:
- Phenol
- Alcohol
- Types: Stellate ganglion or Lumbar spinal

Surgical Sympathectomy:
- No other above method worked
- Ideal for those showing response to sympa nerve blcokade
- Excision or Electrocautery methods used