31: CRPS - Feilmeier Flashcards
define complex regional pain syndrome
poorly understood “chronic inflammatory neuropathic” pain disorder characterized by pain out of proportion of injury and sensory changes
what are the potential causes of CRPS?
- usually occurs after trauma - minor or major
- may have no traumatic, or very minor inciting event (10%)
hyperalgesia
shift in stimulus response to lower pain threshold or increase pain to above pain threshold stimuli
allodynia
pain from non-noxious stimulus on normal skin
sudomotor
edema or sweating abnormalities
trophic changes with CRPS
- Hair and nail growth decreases
- Skin thins
- Fat atrophy
- Adhesions and contractions of tendon and ligaments
end stage CRPS
- decreased ROM
- atrophy
- weakness
- and associated skin changes
theories for pathophys of CRPS
- over activity of sympathetic nervous system (may be a coupling of myelinated A fibers and unmyelentated C fibers to sympathetic nerves)
- peripheral response to nerve injury (normally midportion of nerve can’t create nerve pulses)
- central sensitization (neurons of dorsal horn become sensitized to excess c-nociceptor input)
- May develop after trauma without definable nerve damage (ex: ankle sprain)
- Most common form
- This is where “reflex sympathetic dystrophy” falls
CRPS I
- Or “Causalgia”
- Has the same clinical presentation but there is an identifiable nerve injury
- Nerve injury not complete
CRPS II
synonyms for CRPS
- Reflex sympathetic dystrophy
- Causalgia
- Sudeck’s atrophy
- Sympathetically maintained pain
general definition of CRPS
CRSP describes an array of painful conditions that are characterized by a continuing (spontaneous and/or evoked) regional pain that is seemingly disproportionate in time or degree to the usual course of any known trauma or other lesion. The pain is regional (not in a specific nerve territory or dermatome) and usually has a distal predominance of abnormal sensory, motor, sudomotor, vasomotor, and/or trophic findings. The syndrome shows variable progression over time
Diagnostic criteria for CRPS
- Continuing pain, which is disproportionate to any inciting event
- Must report at least one symptom in three of the four following categories (sensory, vasomotor, sudomotor/edema, motor/trophic)
- must display at least one sign at time of evaluation in two or mor of the following categories (sensory, vasomotor, sudomotor/edema, motor/trophic)
- there is no other better diagnosis
risk factors for CRPS
- female
- smokers
- anxiety/depression
- migraines
- osteoporosis
- preexisting neuropathy
- asthma
- recent menstrual disorders
describe the pain of CRPS
- out of proportion
- allodynia and hyperesthesia
- doesn’t follow dermatome and can spread beyond area of injury
- describe as severe and burning, throbbing or aching
sympathetic changes with CRPS “american flag leg”
- Skin can be red, hot, dry and edematous
- May also become cold, blue, with mottling (livedo reticularus), and hyperhydrosis
dystonia
severe muscle spasms that can cause severe deformity and joint dislocation
Clinical staging of CRPS
Stage I – Acute
- Skin warm, red and dry then may become blue and cold
- May have hyperhydrosis
- Edema
- Severe pain with allodynia and hyperalgesia
Stage II - Dystrophic
- Pain becomes more severe and diffuse
- Edema becomes more hardened and limb can appear brawny
- Hair and nail changes
- X-ray changes
- Muscle wasting begins
Stage III – Atrophic
- Pain may start decreasing but motor and trophic changes increase
- Tissue wasting occurs and can become permanent
radiographic findings sudeck’s atrophy
- Patchy osteoporosis
- Accentuated joints
- Subchondral bone resorption
- Ground-glass appearance
what would a bone scan show for CRPS?
- Three phase technesium 99 bone scan
- Noted increased periarticular uptake, particularly in 3rd phase
- Sensitivity and specificity reported 50-80%
- Sensitivity decrease and specificity increases with disease duration
who do you refer a possible CRPS pt to?
a neurologist, not a pain specialist, because they will do a work up, but then also the pain specialist because they will manage the chronic pain meds
1st line treatment CRPS
physical therapy (steady progression of gentle weight bearing, gradual desensitization to increasing sensory stimuli, massage, continued active and passive ROM)
usually 1st line, short term treatment
corticosteroids ( not for over 1 month )
- treats inflammation, decrease tissue edema, and therefor decrease pain
treatment to reduce bone modeling
bisphosphanates
strong evidence treatment modalities
- physical therapy
- bisphosphonates
- repetitive transcranial magnetic stimulation
things to do to decrease incidence of CRPS
- give local anesthetic block pre-operatively
- vitamin C post-operatively
- early ROM
- careful, meticulous surgical technique
