complex regional pain syndrome Flashcards
complex regional pain syndrome
CRPS
- chronic neuropathic pain that follows limb injury
- pain lasts longer and is more severe than expected for the original tissue damage
- diagnosis is clinical
- AKA reflexive sympathetic dystrophy (RSD)
CRPS affects UE or LE?
- both
- more common in UE
CRPS associations
related to:
* crush injuries
* distal radius fracture
* tibial fracture
* traumatic peripheral nerve injuries
immobilization
higher incidence in smokers
higher incidence with pre-existing fibromyalgia
high percentage of patients had a concomitant stressful life event (around injury or trauma)
more recent CRPS classfications
warm CRPS
* warm, dry
* red
* edematous
* inflammatory
* shorter duration: 4-5 months
cold CRPS
* cold, blue
* sweaty
* less edematous
* not inflammatory
* 20 months
subtypes of CRPS
Type I
* without major nerve damage - pain syndrome triggered by a soft tissue or bone injury not associated with an identifiable nerve injury
* often a crush injury, particularly in lower limb
* following immobilization
* may also follow ampuation, myocardial infarction, stroke, or cancer
Type II
* with major nerve damage (pain syndrome similar to above, involving direct partial or complete injury to a peripheral nerve)
10% have no precipitating event
epidemiology of CRPS
CRPS
- 5.46-26.2 per 100,000 persons/year
- CRPS I > CRPS II
- female > male (3x higher)
- upper limb > lower limb (2x higher)
- mean age 46-52 years
clinical features of CRPS
CRPS
pain: usually described as burning or stinging
sensory
* hyperesthesia: unsual increased or altered sensitivity to sensory stimuli (ramped up NS)
* hyperalgesia: increased sensitivity to pain (pin prick is very painful)
* allodynia: condition in which ordinarily nonpainful stimuli evokes pain (pressure or light touch is painful)
motor
* decreased ROM
* weakness
* fatigue
* tremor
* muscle spasms
* dystonia
trophic: nail growth altered, hair growth, glossy skin
sudomotor (autonomic): edema/swelling
vasomotor: skin color and temperature changes
psychological: anxiety, depression
limitations in activities and participation
CRPS diagnostic criteria - symptoms
continuous pain disproportionate to inciting event AND
symptoms in 3 of 4 categories
* sensory: hyperesthesia and/or allodynia
* vasomotor: temperature asymmetry and/or skin color changes and/or skin color asymmetry
* sudomotor/edema: edema and/or sweating and/or sweating asymmetry
* motor/trophic: decreased ROM and/or motor dysfunction (weakness, tremor, dystonia) and/or trophic changes (ahri, nail, skin)
CRPS diagnostic criteria - physical exam findings, signs
must display at least 1 sign at time of evaluation in 2 or more categories:
* sensory: evidence of hyperalgesia (to pinprick) and/or allodynia (to light tough and/or temperature sensation and/or somatic pressure and/or joint movement)
* vasomotor: evidence of temperature asymmetry (>1 degree C) and/or skin color cahnge and/or asymmetry
* sudomotor/edema: evidence of edema and/or sweating changes and/or sweating asymmetry
* motor/trophic: evidence of decreased ROM and/or motor dysfunction (weakness, tremor, dystonia) and/or trophic changes (hair, nail, skin)
CRPS diagnostic criteria
sensitivity: 0.99 (rule out if not present)
specificity: 0.68
patient symptom criteria met AND
provider examination criteria met AND
there is no other diagnosis that better explains signs and symptoms
pathophysiology of CRPS
somatosensory system
* changes that process thermal, tactile, and noxious stimuli
pathophysiology of CRPS
- central sensitization: increased response to stimulus in CNS
- peripheral sensitization: increased nociceptive firing
- release of neuropeptides: substance P, calcitonin
- altered sympathetic nervous system
acute CRPS
reduced SNS function
* vasodilation: warm/red extremity
inflammatory factors
* increased local, system, and CSF levels of proinflammatory factors
* decreased systemic anti-inflammatory factors
chronic CRPS
increased SNS function
* vasoconstriction - cold/bluish extremity
* super-sensitivity to catecholamins - may lead to exaggerated sweating and vasoconstriction
* vasoconstriction may contribute to trophic changes due to local tissue hypoxia
components of pathophysiology of CRPS
genetic factors
psychologcal factors
* emotional arousal -> greater pain intensity
* stress -> altered immune function
diagnostic tests in CRPS
no gold standard test
diagnosis of exclusion
CRPS outcome measures
CRPS severity scale (CSS)
multi-disciplinary approach of care team for CRPS
psychological intervention
* chronic pain expert
* assess pain, coping skills, and drug abuse/misuse potential
* suicide prevention
psychotherapy
* biofeedback: HR and EMG to teach relaxation
* behavior modification: no caffeine/smoking
* relaxation techniques
* breathing exercises
* self-hypnosis
