Complex Regional Pain Syndrome (CRPS) Flashcards
what are the 2 types of CRPS?
CRPS 1: complex disorder that may develop as a consequence of trauma affecting the limb(s) without an obvious nerve lesion
CRPS 2: aka “causalgia,” the same as CRPS, but with a well-defined peripheral nerve injury. May demonstrates neurological symptoms
what are the characteristics of CRPS in children?
often no preceding traumatic event
occurs more often in LEs
osteoporosis is rare
more favorable prognosis than adults
bone scan results more inconsistent with decreased uptake when study is positive
what are the 4 theories to describe CRPS?
- aberrant neurogenic inflammation
- vasomotor dysfunction
- nociceptive sensitization
- neuroplasticity central nervous system
what is the mechanism for the “abberant neurogenic inflammation” theory in CRPS?
the release of neuropeptides in the periphery due to retrograde depolarization, producing vasodilation and protein extravasation
what is the mechanism for the “vasomotor dysfunction” theory in CRPS?
inhibition of sympathetic vasoconstrictor neurons
what is the mechanism for the “nociceptive sensitization” theory in CRPS?
excitation of peripheral nociceptors by cytokines, leading to amplification of signaling
what is the mechanism for the “neuroplasticity of the central nervous system” theory in CRPS?
spinal and cerebral neurons become more responsive, may fire without input and lose inhibition capabilities
what is hyperalgesia?
increased sensitivity to stimulation with a lower threshold to pain
what is hypoesthesia?
decreased sensitivity to stimulation
what is hyperpathia?
excessive reaction to stimuli that outlasts the initiating stimulus and spreads beyond normal dermatomal borders
what is allodynia?
pain arising from a nonnoxious stimuli
what is dysesthesia?
an unpleasant abnormal sensation
what are sudomotor changes?
edema
hyperhydrosis
anhydrosis
whare are trophic changes?
hair changes
loss of skin wrinkles
shiny skin
penciling of fingertips 2/2 palmar pad atrophy
nail changes
what are vasomotor changes?
temperature asymmetry
skin color changes
vasoconstriction
vasodilation
vasomotor spasm
prolonged capillary refill
what are sensory changes?
hyperesthesia
allodynia to light touch
what are motor changes?
weakness
dystonia
what are helpful tests for dianosing CRPS?
**Triple phase bone scan (TPBS)
radiographs to look for osteoporosis
isolated cold stress test
laser Doppler velocimetry
what is a phentolamine test?
mixed 1-/alpha 2-adrenergic antagonist; blocks the sympathic receptors from receiving circulating norepinephrine and epinephrine; specific for SMP
what is the QSART test for CRPS?
measurement o stimulate sweat output; greater and prolonged with a hyperfunctioning sympathetic nervous system
what are the 3 criteria for diagnosis of CRPS?
- an inciting noxious event or an immobilization
- continuing pain, allodynia, or hyperalgesia to any inciting event
- evidence at some point of edema, changes in skin blood flow, or abnormal sudomotor activity in the region of pain
which patients respond best to a stellate ganglion block?
patients with SMP (sympathetically maintained pain) will respond to the blockade because the CNS is not involved. in patients with SIP (sympathetically independent pain), stellate ganglion blocks are often ineffective
what are the required symtoms for a diagnosis of Fibromyalgia?
diagnosis is based on a constellation of symtpoms and exclusion of inflammatory and metabolic diseases. Pain is chronic (>3 mo), widespread, bilateral, and across all 4 quadrants. Tenderness to palpation of at least 11 of 18 defined tender points. Fatigue, disrupted sleep, headaches, and mood disorders are common.
which drugs are helpful in the management of CRPS?
adrenergic compounds
calcium channel blockers
corticosteroids
bisphosphonates
what percentage of patients with CRPS present with osteopenia or osteoporosis?
70-80%
