Transcript Complex Regional Pain Syndrome

Complex Regional Pain
Syndrome
Jeremy Bennett
CRPS History
 CRPS (complex regional pain syndrome) initially considered in




early 1800s by Claude Bernard et al.
During the Civil War it was seen that soldiers who suffered from
low-velocity, high-mass missile injuries developed a neuropathic
pain that was termed "causalgia" by Silas Weir-Mitchell.
In 1940s the term of reflex sympathetic dystrophy came into use
relating the belief of an abnormal efferent reflex from the
sympathetic nervous system to bodily injury.
Since that time much study and frustration has come from this
relatively rare condition of which the pathophysiology is still not
fully understood.
CRPS is rare, but has started to see an increase in dx.
Basics
 Often seen after injury to a limb or related to
some inciting event.
 The patient complains of and can manifest
skin color/ temperature/ appearance changes
in the affected limb.
 Pain often excruciating – burning, tingling,
electric-like, etc. are often symptoms that
patients feel. The pain is often out of
proportion to stimulus or the event.
Physical Appearance
Diagnostic Criteria
IASP (International Assoc for the Study of Pain) diagnostic criteria include
4 subjective and/ or objective findings:
 1. The presence of an initiating event or a cause of immobilization –
peripheral injury or central (stroke, etc)*. (Injury)
 2. Continuing pain, allodynia, or hyperalgesia in which the pain is
disproportiate to inciting event. (Sensory)
 3. Evidence of edema, changes in skin blood flow, or abnormal
sudomotor activity in region of pain. (Vasomotor)
 4. Diagnosis is excluded by the existence of other conditions that would
otherwise account for the degree of pain/ dysfunction.
One symptom from each category (except #1 as 5% of pts lack known
event) and at least one sign from 2 categories must be evident to
diagnose CRPS, at least by research criteria.
*Not always present or identifiable.
CRPS More Widely Diagnosed
Quickly becoming more recognized, and
possibly overly diagnosed for several
reasons:
 The standardization of diagnosis.
 The "discovery" by personal injury lawyers
who use it as a tool for settlements.
 New treatments and research for chronic
pain.
 Patient self-research and the internet.
Diagnostic Si/Sx
 The most common pain finding is a "burning" and
"stinging” sensations that occur spontaneously. This
is seen in as many as 87% of cases.
 69% of patients report hyperesthesia with light touch
(such as clothing laying on the skin or even draughts
of blowing wind).
 Vasomotor dysfunction is manifested by
asymmetrical edema in affected limb, skin color and
temperature changes, abnormal sweating (either
hyperhidrosis or anhidrosis), and skin/ nail changes.
 Patients may also complain of muscle jerking,
myoclonus, or rigidity in affected limb including
contractures of hands and feet.
CRPS II
 The majority of patients seen are diagnosed with
CRPS type I – or reflex sympathetic dystrophy
(RSD). This is the less painful, debilitating of the two.
 CRPS II (causalgia) is related to a known injury to a
specific major nerve with neuropathic pain frequently
following along the distribution of that nerve alone,
though not always.

While the diagnostic criteria of the IASP may apply,
these patients may also demonstrate hypoesthesia in
the nerve distribution associated with electrical shocks
and extreme allodynia. This is rarer than CRPS I and
the patients are often more debilitated.
Treatment
Treatment usually consists of several
objectives:
 Functional restoration of affected limb - often
should be considered first before other
treatments
 Sympathetic and/or motor blocks
 Cognitive behavioral techniques
 Psychotherapy
 Pharmacotherapy
 Occupational and physical therapy
Tx – Functional Restoration
 Functional restoration involves steady progression
from gentle movements to gentle, weight bearing
movement. Results in more active load bearing with
expected gradual desensitization and increased
functionality of limb.
 Examples include moving from silk stimulation to
other cloths and textures, the scrub and carry
technique, and contrast baths that widen the
temperature range that the patient can tolerate.
 If limitations occur then addition of blocks,
pharmacotherapy, etc. can help increase the patient's
tolerance and improvement.
Tx - Psychotherapy
 Psychotherapy is critical to improvement in patients with CRPS.
There is a high incidence of depression and anxiety noted in
many CRPS patients. Unknown at this time if antecedent
psychological factors prior to injury are common.
 CRPS patients also develop a type of PTSD termed
"kinesophobia" or fear of movement related to prior pain or initial
injury. The patient develops "negative reinforcements" through
fear of initial movements that caused the injury of prior
movements that resulted in extreme pain in the past. Fear of
movement often results in contractures and reduced
functionality.
 Cognitive behavioral therapy is the most beneficial
psychotherapy to help patients with these concerns, though
other interventions including family therapy are also beneficial.
Tx - Pharmacotherapy
Pharmacotherapy is often on a trial and error basis and
is very patient specific. Drugs are considered based
on neuropathic pain treatments and then used for
CRPS and have yet to be shown effective in RCTs.
 - initial drug(s) to consider include gabapentin and
pregabalin (both used for neuropathic pain) and are
approved for these conditions
 - TCAs often used for patients with sleep
disturbances, but are hindered by their numerous
side effects and drug interactions; not currently
approved for pain treatment
Tx - Pharmacotherapy
 - SSRIs and SNRIs like fluoxetine and duloxetine,
resp, are often used with the latter being approved for
neuropathic pain conditions.
 - Opioids should be avoided as much as possible as
their effectiveness is not well proved and
dependence/ addiction are serious concerns in CRPS
patients.
 - Intrathecal baclofen, IV steroids, IVIG, and
anticonvulsant medications are all treatments that
have been considered and used with variable
success, though studies are still lacking.
Tx – Interventional Approaches
 Considering the nature of the sympathetic
involvement in the patient, blocking the sympathetic
nervous system seems inherent towards
improvement.
 Cervical and lumbar sympathetic blocks are
frequently performed as outpatient procedures with
patients receiving a few weeks or months of relief.
Often done to help with movement therapies.
 Beir blocks with local anesthetics, guanethidine, or
other neurolytic agents have been performed with
varying success.
 SCS, pump implantation, and thermocoagulation
have also been used to treat patients with CRPS with
variable success rates.
Despite the belief that blocking the sympathetic
nervous system will result in reduced pain,
many patients do not gain substantial benefit
from these procedures for any substantial
length of time and the procedures themselves
may actually exacerbate the patient's pain.
CRPS Prognosis
 Overall the prognosis for patients with CRPS is
relatively low. Effective treatments are very patient
specific and patient satisfaction, mental state,
willingness to be involved in their treatment all
contribute to their pain reduction.
 Many patients report extreme lack of satisfaction with
their pain control and are usually disabled.
 More research is required into chronic pain and
developing better methods to treat chronic autonomic
dysfunctional pain.
References
 Harden RN, Complex Regional Pain
Syndrome,
British Journal of Anesthesia,
2001, 87, pp. 99-106.
 Schott GD, Complex? Regional? Pain?
Syndrome? Practical Neurology. 2007, 7,
pp.
145-157.
 Forouzanfar T, et al. Treatment of Complex
Regional Pain Syndrome Type I.
European
Journal of Pain. Vol 6, issue 2.
Apr 2002. pp. 105-122.