Complex Regional Pain Syndrome (CPRS)
UPDATED ACTUAL Exam Questions and
CORRECT Answers
CRPS Type 1 (RSD-reflex sympathetic dystrophy) - CORRECT ANSWER - -Presence of
initiating noxious event or a cause of immobilization (likely no direct nerve damage)
-CRPS Type 1
CRPS Type 1Complex Regional Pain Syndrome (CRPS) is a chronic pain condition that most
often affects a person's limbs. The typical areas that CRPS can affect are the arms, legs, hands, or
feet. The condition usually
occurs after some kind of injury or trauma to the area. CRPS is thought to be the result of
damage or malfunction of central or peripheral nervous system.
There are two forms CRPS and they are referred to as CRPS Type 1 and CRPS Type 2. CRPS
Type 1 is also known as Reflex Sympathetic Dystrophy Syndrome (RSDS). However, most
clinicians will refer to the condition as CRPS Type 1. Both conditions are characterized by
excessive or prolonged pain and dramatic or mild changes in skin tone, temperature, or swelling
in the area.
Causes of CRPS Type 1
The exact causes of specific cases of CRPS Type 1 may be unknown but the condition usually
results from an injury of some kind the affected limb. CRPS Type 1 may be in some way related
to genetics so a family history of CRPS Type 1 may predispose a patient to developing the
condition. CRPS Type 1 is also more likely to occur in individuals with some kind of nervous
system dysfunction.
Fractures or sprains are the injuries most likely to cause CRPS Type 1. For example, if a cast is
put too tight around a broken limb the patient may develop CRPS Type 1. A sprain, or
stretch/tear in a ligament, can also lead to CRPS Type 1. Since ligaments are the tissues that
connects bones to one another, this can also lead to other medical complications, as well. Other
risks for CRPS Type 1 are surgery and preexisting medical conditions such as heart attack,
stroke, infection, and cancer.
-Continuing pain, allodynia, or hyperalgesia with which the pain is disproportionate
, CRPS Type 2 (Causalgia) - CORRECT ANSWER - -The presence of continued pain,
allodynia, or hyperalgesia after a nerve injury, not necessarily limited to the distribution of the
injured nerve
-Evidence at some time of edema, changes in skin blood flow, or abnormal sudomotor activity in
the region of the pain
--This diagnosis is excluded by the existence of conditions that would otherwise account for the
degree of pain and dysfunction
IASP Criteria for Dx of CRPS - CORRECT ANSWER - 1. Presence of an initiating
noxious event or reason for immobilization
2. Disproportional pain, allodynia, or hyperalgesia from a known inciting event
3. Sign or symptom of any evidence showing edema, skin changes, blood flow, or abnormal
sudomotor activity in the region of the pain
4. No other condition that would otherwise explain the degree of pain or dysfunction
Pathophysiology of CRPS - CORRECT ANSWER - Somatosensory Abnormalities
-Nerve fibers - Lower density of C and A fibers in affected limbs --> sensory deficits in affected
limbs
-Brain plasticity
--decreased activity in the somatosensory cortex of affected side
--Somatotropic reorganization results in tactile mislocation - directly correlates with hyperalgesia
Sensory Pathways
-Central sensitization - neuropeptides substance P and bradykinin released in response to
nociceptive stimuli --> activate NMDA receptors -->hyperalgesia/allodynia
-Peripheral sensitization - increased pro-inflammatory factors --> increased nociceptive
sensitivity and a decreased threshold for firing of nociceptive stimuli
Sympathetic nervous system
Excessive outflow from the SNS
UPDATED ACTUAL Exam Questions and
CORRECT Answers
CRPS Type 1 (RSD-reflex sympathetic dystrophy) - CORRECT ANSWER - -Presence of
initiating noxious event or a cause of immobilization (likely no direct nerve damage)
-CRPS Type 1
CRPS Type 1Complex Regional Pain Syndrome (CRPS) is a chronic pain condition that most
often affects a person's limbs. The typical areas that CRPS can affect are the arms, legs, hands, or
feet. The condition usually
occurs after some kind of injury or trauma to the area. CRPS is thought to be the result of
damage or malfunction of central or peripheral nervous system.
There are two forms CRPS and they are referred to as CRPS Type 1 and CRPS Type 2. CRPS
Type 1 is also known as Reflex Sympathetic Dystrophy Syndrome (RSDS). However, most
clinicians will refer to the condition as CRPS Type 1. Both conditions are characterized by
excessive or prolonged pain and dramatic or mild changes in skin tone, temperature, or swelling
in the area.
Causes of CRPS Type 1
The exact causes of specific cases of CRPS Type 1 may be unknown but the condition usually
results from an injury of some kind the affected limb. CRPS Type 1 may be in some way related
to genetics so a family history of CRPS Type 1 may predispose a patient to developing the
condition. CRPS Type 1 is also more likely to occur in individuals with some kind of nervous
system dysfunction.
Fractures or sprains are the injuries most likely to cause CRPS Type 1. For example, if a cast is
put too tight around a broken limb the patient may develop CRPS Type 1. A sprain, or
stretch/tear in a ligament, can also lead to CRPS Type 1. Since ligaments are the tissues that
connects bones to one another, this can also lead to other medical complications, as well. Other
risks for CRPS Type 1 are surgery and preexisting medical conditions such as heart attack,
stroke, infection, and cancer.
-Continuing pain, allodynia, or hyperalgesia with which the pain is disproportionate
, CRPS Type 2 (Causalgia) - CORRECT ANSWER - -The presence of continued pain,
allodynia, or hyperalgesia after a nerve injury, not necessarily limited to the distribution of the
injured nerve
-Evidence at some time of edema, changes in skin blood flow, or abnormal sudomotor activity in
the region of the pain
--This diagnosis is excluded by the existence of conditions that would otherwise account for the
degree of pain and dysfunction
IASP Criteria for Dx of CRPS - CORRECT ANSWER - 1. Presence of an initiating
noxious event or reason for immobilization
2. Disproportional pain, allodynia, or hyperalgesia from a known inciting event
3. Sign or symptom of any evidence showing edema, skin changes, blood flow, or abnormal
sudomotor activity in the region of the pain
4. No other condition that would otherwise explain the degree of pain or dysfunction
Pathophysiology of CRPS - CORRECT ANSWER - Somatosensory Abnormalities
-Nerve fibers - Lower density of C and A fibers in affected limbs --> sensory deficits in affected
limbs
-Brain plasticity
--decreased activity in the somatosensory cortex of affected side
--Somatotropic reorganization results in tactile mislocation - directly correlates with hyperalgesia
Sensory Pathways
-Central sensitization - neuropeptides substance P and bradykinin released in response to
nociceptive stimuli --> activate NMDA receptors -->hyperalgesia/allodynia
-Peripheral sensitization - increased pro-inflammatory factors --> increased nociceptive
sensitivity and a decreased threshold for firing of nociceptive stimuli
Sympathetic nervous system
Excessive outflow from the SNS
