• Forearm and hand
• Knee, calf, and foot

Patient Profile

• Commonly 40-50 years old (but also children and elderly)
• Fracture in history
• Female > Male (2-3:1)
• Upper extremity > Lower extremity (2:1)

Pathophysiology

Trigger

• Fracture or surgery (40%), surgical median nerve decompression (30%), traumatic nerve- or myelonlesion, trivial trauma, idiopathic
• Typically no correlation between severity of the trauma and severity of CRPS

Source

• Genetic predisposition not proven but assumed plausible
• Central pain mechanisms
• Dysfunction of tissue healing mechanisms and vegetative nervous system

Pain Mechanisms

• Peripheral nociceptive: neurogenic inflammation; release of substance P, increase in pro-inflammatory zytokines – decrease of anti-inflammatory zytokines
• Peripheral neurogenic: neural lesion in CRPS 2
• Central mechanisms: Cortical changes, representation of affected extremity changes in somatosensory cortex
• Output: Widespread autonomic disturbances; vegetative disturbances; trophic changes

Course

Constant. Independent from time of day. Spontaneous exacerbations. Highly dependent on individual factors. Early management increases chances of rehabilitation, multidisciplinary management for optimal results.

History

CRPS 1: Commonly trauma in history but also trivial trauma as possible cause; wearing a cast for several weeks

CPRS 2: Surgery or neural tissue trauma in history. Usually short history as diagnosis is made relatively fast by specialist

• Constant pain with exacerbations
• Burning
• Stinging
• Aching
• Deep (muscle/bones 68%) > superficial (skin 32%)
• Weakness
• Myoclonus
• Dystonia
• Temperature difference
• Perspiration
• Skin discoloration/surface changes
• Dysesthesia
• Not clearly associated with a specific innervated area

Physical Examination

Inspection & Palpation
Skin color changes, Perspiration disturbed at affected site, atrophy, hair and nail growth increased, skin temperature changes, contractures

Active Examination
Loss of strength, limited ROM in affected joints due to edema: in later stages fibrosis

Functional Assessment
Inability to make a fist, gait disturbances, fine motor tasks impaired

Neurological
Motor: Pincer grip & making a fist are weak; grasping objects only with visual help; tremor; myoclonus and dystonia.

Sensory: Allodynia and hyperalgesia; sensory disturbance (hyperesthesia or hypalgesia)

Passive Examination
PROM limited in affected joints

Additional Tests
Graphestesia: Drawn shapes (numbers, letters) are not recognized in affected area; Two Point Discrimination (TPD) increased in affected area; drawing of own body: affected limb depicted smaller in size

Differential Diagnosis

1. Rheumatic diseases
2. Inflammation (e.g. post-surgical infection)
3. PAD
4. Thromboembolic disorders
5. Compartment syndrome
6. PEP

Strategy

Individualized graded exposure. Start early therapy to reduce the risk of chronicity

Interventions

• Reduce edema
• Explain pain
• Recognition: Recognizing body parts on pictures
• Imaginary movements: Picture showing a movement and imagine how to do that movement
• Mirror therapy: Activation of mirror neurons influences frontal cortex
• Antiinflammatory, antineuropathic, antioxidative drugs, opioids
• Spinal cord stimulation in severe chronic pain
• Occupational therapy
• Psychotherapy

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