Complex regional pain syndrome is a multifactorial syndrome of pain affecting mainly limbs (Upper>lower) and other body parts. Females are affected more than males (4:1). No definitive investigation is available. Early treatment is better to avoid consequences and complications.

1. Current Designation: Senior Consultant & In-charge Pain Relief Service
Qualifications: MD, DNB, MNAMS, FIPM, FIPP, FAMS
Institution: Tata Motors Hospital , Jamshedpur
Areas of interest:
 Interventional Pain Management,
 Labour Analgesia
 Ultrasound Guided Blocks
Publications:
 106 Indexed Publication (National & International) &7 chapters in books
Awards:
 Fellow Interventional pain practice (FIPP)
 Awarded Adjunct Professor by National Board
 Awarded Academic Professor by IMA
 Alankar award,
 Nomination for Pain physician award,
 Lifetime Achievement award,
 Kop’s Best Paper (pain Section)
Dr. Ashok Jadon

2. Complex Regional Pain Syndrome (CRPS)
- an update

3. Definition (by ISSP):
• A syndrome characterized by a continuing (spontaneous and/or
evoked) pain that is seemingly disproportionate in time or degree
to the usual course of pain after trauma or other lesion.
• The pain is regional (not in a nerve territory or dermatome)
• Usually has a distal predominance of abnormal sensory, motor,
sudomotor, vasomotor, edema, and/or trophic findings.1
1. Merskey H, Bogduk N. Classification of Chronic Pain. 2nd (Revised) ed. IASP Task
Force on Taxonomy, IASP Press, 2011; 4–7.

4. Definition:
CRPS is a debilitating, painful condition associated with,
Sensory
Motor
Autonomic and
Trophic (skin and bone) abnormalities

5. WHY it is called: C-R-P-S
COMPLEX-Varied pathogenesis and dynamic clinical presentation
REGIONAL-Regional distribution of symptoms
PAIN-Out of proportion to the inciting events
SYNDROME-Constellation of symptoms and signs

6. Synonyms of CRPS
Reflex Sympathetic Dystrophy (RSD)
Causalgia
Reflex neurovascular dystrophy (RND)
Amplified musculoskeletal pain syndrome(AMPS)
Algoneurodystrophy

7. Pathogenesis: What happens
CRPS is a multifactorial disorder
Nociceptive dysfunction causing
extreme sensitivity.
Neurogenic inflammation.
Vasomotor dysfunction.
(an aberrant response to tissue injury)

8. All that leads to….
Maladaptive
neuroplasticity
CNS & ANS (Deregulation)
Functional loss,
impairment and disability.

9. Pathophysiology
• Biochemical changes in the local milieu after injury:
• B-cell activation,
• Increased interleukin(IL)-1β and substance P (SP)
signaling,
• Regional disturbances in sympathetic nervous system
(SNS) in the affected limb
• Systemic disturbances in ANS
• Central changes in autonomic drive.
[47–49]

10. Autonomic Nervous System Mechanisms
• Reduction in turnover of the SNS norepinephrine,
• Unregulated adrenoceptor responses,
• Activation of α1-adrenoceptors on primary afferent fibers by
norepinephrine
54
 Leads to altered vasoregulation in the affected limb.
 Mechanical allodynia and punctate hyperalgesia
associated with CRPS

11. Central Nervous System Mechanisms
• Cortical reorganization (CR)
• Reduction in size of the representation of the CRPS-affected limb
in the somatosensory cortex
• Impairments in endogenous pain inhibitory pathways in the
brain.
• increased glucose metabolism in pain-related brain regions,
• Alterations within the default mode network during resting-
state fMRI.
63,64,65

12. Evidence for CNS Mechanisms
• Degree of cortical reorganization is positively correlate with
the pain intensity and the amount of hyperalgesia.
• Treatment of CRPS have shown:
• Reversal of reorganization
• Enhanced functional connectivity between the areas
which are primary source of endogenous pain inhibition
(dorsolateral prefrontal cortex and the periaqueductal
gray).

13. Inflammatory Mechanisms
• Pro-inflammatory cytokine pattern
• Neuroinflammation (increased microglial activation)
• Neurogenic inflammation: it occurs when peptidergic
primary afferents are activated and release SP or
calcitonin gene-related peptide (CGRP)

14. Immune Mechanisms (IM)
• Autoimmunity: presence of antinuclear antibodies and serum-
autoantibodies (surface-binding immunoglobulin G (IgG).
• Abnormalities in T-cell sub-populations.

15. Experimental evidences
• Administration of IgG from CRPS affected animal can induce
CRPS-like features in animals following injury
• The main antibody effect is limb-confined pain-sensitization.
• Importantly, the changes induced are strictly unilateral –
affecting only the injured rodent limb.
• There is no systemic inflammatory response and no regional
tissue destruction.

16. Genetic Factors and Epigenetic Changes
• Many cases in family relatives suggests a potentially
heritable component of CRPS risk.
• The most consistent genetic findings suggest genetic
differences in the human leukocyte antigen (HLA).
• DNA methylation at COL11A1 and HLA-DRB6 genes.
• Differential gene expression in the HLA-DRB6 gene.
96–98

17. Does Psychological Factors Play a Role in the
Development of CRPS
• Systematic review and Meta-analysis shows that there
is no association between a variety of psychological
factors and the development of CRPS.

18. Types of CRPS
There are 3 variants of CRPS:
TYPE I: Develops after injury and no nerve lesions found.
TYPE II: There is evidence of obvious nerve damage
CRPS-NOS (not otherwise specified): Partially meets CRPS
criteria; not better explained by any other condition.
“CRPS with Remission of Some Features”

19. Clinical presentation
Middle aged (40-50yrs)
F:M 4:1
Upper limb > Lower limb> other parts
Pain > expected
Swelling, Loss of Movements
Temperature warm or cold,
Skin and hairs changes
Depression and hopelessness

20. • Disconnect from of body parts & Distorted image of body part
• Whereby the limb may feel foreign (“cognitive neglect”) and
• Directed mental and visual attention is needed to move the limb
(“motor neglect”).

21. Acute (Stage 1):
Begin after injury for up to 3 months
characterized by
severe burning pain at the site of
injury.
Muscle spasm, Joint stiffness
Restricted mobility.
This stage lasts a few weeks.
It can subside spontaneously or
respond rapidly to treatment.

22. Dystrophic (Stage 2):
6weeks to 1 year
The pain intensity increases
Allodynia
Swelling spreads, hair growth
diminishes, nails become
cracked,
Osteoporosis becomes severe.

23. Atrophic (Stage 3):
After 6months to may be forever
Irreversible changes in the skin and bones.
Marked muscle atrophy & contractures.
The limb has ‘woody’ feel on examination.
The nails become brittle.
Occasionally, the limb is displaced from its
normal position.
Severe osteoporosis with washed out
appearance of bone on X-ray

24. Diagnosis:
Diagnosis is mainly clinical
Typical history and
Evolution of symptoms
Budapest diagnostic criteria
 Investigations are non-specific

25. Budapest Criteria
Symptoms
Must report at least one symptom in two or
more of the following categories:
a. Sensory: hyperesthesia or allodynia
b. Vasomotor: temperature asymmetry and /or
skin color changes and/ color asymmetry
c. Sudomotor : edema & or sweating changes,
or sweating asymmetry
d. Motor or trophic: decreased ROM or motor
dysfunction (weakness, tremor, or dystonia),
and/or trophic changes (hair, nails, or skin)
Signs
• Must display at least one sign at time of
diagnosis in two or more of the following
categories:
a. Sensory: hyperalgesia, allodynia)
b. Vasomotor: temperature asymmetry & or
skin color changes and/or asymmetry
c. Sudomotor: edema & or sweating
changes and/or sweating asymmetry
d. Motor or trophic: decreased ROM or
motor dysfunction & trophic changes
(hair, nails, or skin)
No other diagnosis, better explains the signs and symptoms

26. Investigations and diagnostic tests:
1. Thermography:
2. Sweat testing: Abnormal sweating detection

27. Diagnostic Tests Cont.…
Radiography: Patchy osteoporosis
Quantitative Sensory Testing and Autonomic
Testing:
Increase in warm perception thresholds and
decrease of cold pain thresholds .
Three phase bone scintigraphy
Electro-diagnostic Testing:
Nerve conduction & myography
Regional intravenous blockade with
guanethidine (not done now)

28. Differential Diagnosis of CRPS
1. Inflammation: Erysipelas, Arthritis
2. Vascular diseases: Thrombosis, Atherosclerosis, Raynaud’s disease
3. Neuropathic Pain: Poly neuropathy, Nerve entrapment, Radiculopathy
Post herpetic neuralgia, pain after CVA
4. Myofascial Pain (Overuse/ Disuse): Tennis elbow, Repetitive strain
5. Fibromyalgia
6. Psychiatric: Somatoform pain disorders, Munchhausen syndrome
7. Rheumatologic diseases

29. Treatment: (Evidence based)
Drugs: NSAIDs, Gabapentin, Pregabalin, alpha- or beta- blockers.
Opioids, bisphosphonates, vasodilators,
Antidepressants.
Mirror box therapy
Tactile discrimination training
Biofeedback, psychotherapy, and hypnosis.
Intravenous regional sympathetic blockade (- ve. evidence)
Epidural or Intrathecal drugs: LA, clonidine, opioids, baclofen (+2C)

30. Sympathetic Ganglion Blockade:
Stellate Ganglion Block
(upper extremity)
Lumbar Sympathetic Block
(lower extremity)

31. Treatment Cont.….
Newer therapeutic options:
 Intramuscular Botox injections,
Repetitive transcranial magnetic simulation,
Hyperbaric oxygen,
intravenous infusion of immunoglobulin,
sub-anaesthetic infusion of ketamine
Spinal cord stimulation (+2B) (used when other technique failed)
Sympathetic blockade with Local anesthetic and Sympathetic
denervation:
Stellate ganglion Block
Lumbar Sympathetic Block (Both +2B)
 Physiotherapy

32. Stellate Ganglion Block
Star shaped ganglia
Fusion of inf. Cervical &
1st Thoracic ganglia
Over the head of 1st rib
Approaches: Transverse
process of C6 Vs C7
C6 better for blind technique
C7 for fluoroscopic and USG
Techniques…..
C6
C7

33. Classical C6 (Blind approach)

34. Fluoroscopic Technique
C6
C7
T1

35. Monitoring in SGB

36. Stellate Ganglion Block: FAQs
How many injections for treatment
How frequently
With steroid or without steroid
What local anaesthetic
What next if ineffective or effective but short lived effect
 Our Experience….
Approx. 40 cases 2-3 injections at weekly interval
6-8ml (1% xylocaine or 0.2% Ropivacaine) plus 80mg Depomedrol
RF for resistant cases
T2-T3 for Kuntz’s Nerves

38. Radio Frequency at SG

40. A case of Refractory CRPS

41. C2-C3 Sympathetic block

42. Lumbar Sympathetic Ganglion Block

43. Lumbar Sympathetic Ganglion Block

44. Safety Vs Risks of Interventional Treatment
Inherent risks of interventional procedures:
Infection, Injury to organs/ nerves, Intravascular injection
Safe if done with safety
Requires knowledge of anatomy
Proper technique
Adequate training
Do not rely on one treatment
Try multimodal approach

45. Treatments to be avoided:
Deep brain stimulation is ineffective
High dose opioid should be avoided
Hyperalgesia,
Addiction,
Diversion risk (unlawful use) and
over-dosage.

46. Prognosis: Take Home Message
If treatment is begun early CRPS can be
treated successfully.
If treatment is delayed prognosis is guarded.