Chapter 192 - Complex regional pain syndrome Flashcards
Complex regional pain syndrome other historic names
1) posttraumatic pain syndrome
2) causalgia
3) reflex sympathetic dystrophy
and many more
Epidemiology of CRPS
incidence
gender ratio
age
1-12% with peripheral nerve injury
female 2-4x more
higher in elderly
CRPS causes three types
1) traumatic
2) nontraumatic
3) idiopathic
Traumatic causes of CRPS
1) fracture
2) dislocation
3) sprains
4) crush injury
5) burns
6) iatrogenic injury
Most commonly involved never in traumatic causes of CRPS
1) median nerve
2) sciatic nerve
Nontraumatic causes of CRPS
1) prolonged bed rest
2) neoplasm
3) metabolic bone disease
4) DVT
5) MI (5-20% get CRPS)
6) CVA
Shoulder-hand syndrome
chronic pain of UE secondary to MI
Sudeck atrophy
post-traumatic reflex dystrophy with bone involvement on XRAY
Three components of CRPS
Complex: dynamic and variable presentation
- autonomic, cutaneous, motor, inflammatory, dystrophic changes
Regional: distribution of symptoms beyond area of original region
Pain: pain out of proportion
- burning, thermo, allodynia
Types of CRPS
TYPE 1 = reflex sympathetic dystrophy
TYPE 2 = causalgia
Diagnostic criteria for CRPS TYPE 1
1) history of inciting event
2) spontaneous pain, hyperalgesia, allodynia beyond the territory of single peripheral nerve
3) disproportionate to initial event
4) edema, blood flow abnormality and abnormal sudomotor activity since initial event
5) absence of other conditions
Diagnostic criteria for CRPS TYPE 2
1) history of nerve injury
2) spontaneous allodynia or pain not limited to region of injury
3) edema, temperature and skin blood flow abnormality, abnormal sudomotor or motor dysfunction in region of pain since original nerve injury
4) absence of other conditions
CRPS NOS
not otherwise specified
subtype that partially meet current criteria but previous criteria said CRPS
Theories of CRPS pathogenesis
1) exaggerated local inflammatory response (neurogenic inflammation)
- elevated inflammatory mediators
- steroids help treat symptoms
2) sympathetically mediated syndrome
- sympathectomy may help short term but no long term effect
3) ischemia reperfusion injury
- vasoconstriction from inflammation and resultant vasodilation pain
- tadalafil helps with pain
4) central sensitization theory
- NMDA receptor caused pain
- ketamine (NMDA antagonist) helps
5) nerve damage
- amputated limbs show small fiber loss in CRPS
6) autoimmune
- antineuronal autoantibodies in 30-90% of CRPS
- IVIG helps with pain
7) cortical reorganization theory
- altered sensory representation of affected limb
- computer-based graded motor imagery helps
- mirror therapy helps
Trophic changes in CRPS
nail atrophy/hypertrophy hair growth cahnges skin atrophic motor dysfunction loss of ROM
Budapest consensus criteria on CRPS
1) pain disproportionate to event
2) have > 1 symptom of the following:
a) vasomotor: temperature or color asymmetry
b) sensory: hyperesthesia or allodynia
c) motor/trophic: decrease ROM, weakness, trophic changes
d) sudomotor/edema: sweating, edema
3) have > 2 signs of the same 4 domains
4) no other diagnosis
Adjunctive tests for CRPS
1) pulse oximetry
2) nerve conduction studies
3) neuroinflmmatory mediators: substance P, bradykinin, CGRP
CRP, ESR, WBC should not be elevated
4) bone scan - non specific
5) MRI - non specific
Temperature rise with sympathetic blockade
1-3 C
CRPS pain relief with sympathetic blockade (immediate)
75-100%
less is non-specific
Sympathetic blockade agents
1) iv alpha blocking phentolamine
2) iv bretylium
3) Bier blockade
4) spinal block
5) epidural
6) local anesthetic of paravertebral lumbar sympathetic chain (lidocaine or bupivacaine)
First line treatment for CRPS
Physiotherapy
Goals of physiotherapy
1) mobilization, swelling control, isometric strengthening
2) desensitization of affected region
3) stress loading, isotonic strengthening, ROM, postural normalization and aerobic doncitioning
4) vocational rehabilitation
Adjunctive therapy to physiotherapy
1) mirror visual feedback
2) pain exposure physical therapy
3) transcutaneous electrical nerve stimulation
4) acupuncture and electroacupuncture
Pharmacological therapy classes for CRPS
1) opioid: inhibit central nociception (mu receptors)
2) tricyclic antidepressants: inhibit reuptake monoaminergic transmitters
3) GABA agonist (gabapentin/neurontin)
4) alpha-adrenergic blocker: phentolamine, phenoxybenzamine, prazosin
5) beta blocker: propranolol
6) CCB: muscle relaxation increase blood flow
7) Bisphosphonate: inhibit osteopenic activity
8) NSAID
9) steroids
Sympathetic blockade in CRPS key points
1) temporary response
2) diagnostic
3) can reverse process if done in first 6 months
4) reduce pain score and depression in long run
5) no effect on long term quality of life
Epidural and intrathecal drug therapy in CRPS
effective but expensive and may require hospitalization
Drucker’s three stages of CRPS
Stage 1: 0-3 months
Stage 2: 3-6 months
Stage 3: after 6 months
Surgical sympathectomy pain relief in patients that benefited from sympathetic blockade with local anesthetic
90%
Level of ganglionectomy
L2 + L3 +/- L4
Problem with bilateral high ganglionectomy (L1)
Ejaculatory disturbances
Chemical sympathectomy
L2, L3, L4 vertebrae injection of 3 ml of 6.5-7% phenol in water
or 3ml of absolute alcohol
Open sympathectomy steps
flank incision
split external, internal obliques and transversus abdominus
Stay retroperitoneal
Identify lumbar sympathetic chain behind IVC or aorta
Pain relief after sympathectomy
94%
Complications of sympathectomy
1) injury to genitofemoral nerve, ureter, lumbar vein, aorta, IVC
2) neuralgia 50% (ache in anterolateral thigh) - resolves 12 weeks later
3) retrograde ejaculation 25-50% if L1 sympathectomy bilateral
Treatment guidelines for CRPS TYPE 1 by stages
Stage 1: physiotherapy +/- TENS; sympathectic blockade, steroid
Stage 2: surgical sympathectomy considered as well
Stage 3: neuromodulation, maniputation of joint under anesthesia, antidepressant, vocational guidance
