Complex Regional Pain Syndrome
Dr. Dawood Nasir
Definition
• CRPS: Complex regional Pain Syndrome, a
neuropathic pain syndrome associated with
sympathetic nervous system dysfunction
• CRPS1: Previously known as Reflex sympathetic
dystrophy, is a syndrome occurring after minor
trauma
• CRPS 11: Causalgia, usually occurs after major
nerve injury
Complex Regional Pain Syndrome
Pathophysiology
• Peripheral & Central Mechanism
• Proposed mech include
- Sensitization of small diameter polymodal C &
A delta afferent fibers
- Sensitization of central wide dynamic range
neurons
- Altered activity of low threshold A beta fibers
Question
• Complex regional pain syndrome type 11
(Causalgia) is differentiated from complex
regional pain synd type 1 by knowledge of
A. Etiology
B. Chronicity
C. Affected body region
D. Type of symptoms
E. Rapidity of onset
Answer (A)
• Complex regional pain syndrome type 1 is a
clinical syndrome of continuous burning pain
usually occurring after an injury or surgery. Pts
present with variable sensory, motor, autonomic,
& trophic changes. Complex regional pain
syndrome type 11 exhibits the same features as
complex regional pain syndrome type 1, but the
etiology is damage to a major nerve.
Epidemiology
• Incidence
- Unknown
• Prevalence
- Unknown
- Women predominate (60-80 percent)
- Mean age: 36-42 years
• Genetics
- Genetic correlation debated
Diagnostic criteria
At least 4 of the following must be present to
diagnose CRPS
Examination findings:
1. Temperature / Color change.
2. Edema
3. Trophic skin, hair, nail growth abnormalities.
4. Impaired motor function.
5. Hyperpathia / Allodynia
6. Sudomotor changes
Diagnostic criteria-cont• Diagnostic test results
- Three phase bone scan that is abnormal in
pattern characteristic.
- This test is not needed if 4 or more of
examination findings are present.
Stages of Complex regional type 1
• CRPS 1 is divided into 3 stages
1. Acute
2. Dystrophic
3. Atrophic
Acute phase
•
•
•
•
Pain: Localized, Severe, Burning
Extremity : Warm, swollen, nail growth
Skin: Dry & red, growth of hairs
X-ray: Normal
Mech.: Could be due to increase blood supply
Dystrophic Phase
• Pain: Diffuse, throbbing
• Extremity: Cold, Cyanotic, edematous, muscle
wasting.
• Skin: Sweaty, thinning or loss of hairs
• X-ray: Reveals osteoporosis
Mech.: Could be due to vasoconstriction
Atrophic Phase
•
•
•
•
Pain: Less severe, may involve other extremities
Extremity: Severe muscle atrophy, contractures
Skin: Glossy & atrophic
X-ray: Reveals severe osteoporosis, & ankylosis
of joints.
Mech.: Could be due to disuse atrophy
Physical Exam
• Allodynia: Perception of non noxious stimulus as
painful
• Hyperesthesia: Increased response to mild stimulus
• Skin discoloration/mottling
• Dry glossy extremity
• Sweating
• Edema
• Abnormal temperature
• Weakness, tremor, Hyperkeratosis, Brittle nail
Question
• Allodynia is defined as
A. Spontaneous pain in an area or region that is
anesthetic
B. Pain initiated or caused by a primary lesion or
dysfunction in the nervous system.
C. An unpleasant abnormal sensation, whether
spontaneous or provoked
D. An increased response to a stimulus that is
normally painful
E. Pain caused by a stimulus that does not
normally provoke pain.
Answer (E).
• The IASP has defined several pain terms.
Anesthesia dolorosa: refers to spontaneous pain
in an area or region that is anesthetic.
Neuropathic pain: is caused by dysfuction in NS.
Dysthesia :is unpleasant abnormal sensation.
Hyperalgesia :is increased response to painful
stimulus.
Allodynia: is pain caused by a stimulus that does
not normally provoke pain.
Tests
• Imaging
- Osteoporosis or fine demineralization on xray
- Increased periarticular uptake in delayed bone
scintigraphy
Pathological findings
• Reduced thermoregulatory reflexes
• Changes in sudomotor neuron activity
• Neurogenic inflammation
Question
• Which of the following choices is not
consistent with a limb affected by complex
regional pain syndrome?
A. Osteoporosis.
B. Allodynia.
C. Dermatomal distribution of pain
D. Atrophy of the involved extremity.
E. Hyperesthesia.
Answer ©
• CRPS are associated with trauma. The main
feature is burning & continuous pain ie
exacerbated by normal movement, cutaneous
stimulation, or stress usually weeks after the
injury. The pain is not anatomically distributed.
Other associated features include cool, red,
clammy skin & hair loss in the involved extremity.
Chronic cases may be associated with atrophy &
osteoporosis.
Differential Diagnosis
•
•
•
•
•
•
•
•
Infection
Hypertrophic scar
Bone fragments
Neuroma
Radiculopathy
Joint contracture
CNS tumor
Syringomylia
Medications
• First line
- Anticonvulsants
1. Gabapentin up to 900 mgs PO q8 hrs.
2. Pregabalin up to 300 mg PO q 12 hrs
- Tricyclic antidepressants:
1. Amitriptiline up to 150 mgs PO qhs
2. Nortriptylene: upto 150 mgs PO qhs
3. Desipramine: upto 150 mgs PO qhs
- NSAIDs: If no complications
Second Line
•
•
•
•
•
•
Other anticonvulsants
Oxcarbazepine upto 600 mg PO q12 hrs
Lamotrigine upto 150 mgs PO qhs
Short & long acting opioids (Controversial)
Alpha adrenergic blocking agents
Corticosteroids(Short term only)
Biphosphonates
Topical therapies
Interventional
• Regional anesthetic approaches
• Sympathetic blockade (local with or without
steroids)
• Peripheral nerve blockade
• IV regional analgesia (reserpine, guanethidine,
bretylium)
• Chemical sympathetic neurolysis
• Radiofrequency sympathetic rhizotomy
• Epidural clonidine
• Spinal cord stimulation
Rehabilitation
•
•
•
•
•
•
•
•
Avoid immobilization
Desensitization
Mobilization
Edema control
Isometric/Isotonic strengthing
Stress loading/range of motion
Aerobic conditioning
TENS
Mental Test/Behavioral
•
•
•
Psychometric testing
Counseling
Behavioral modification
Relaxation therapy
Group therapy
Self-hypnosis
Psychotherapy
Medical management of depression
Technique for Stellate ganglion Block
• Pt. supine, head midline, mouth slightly open
• 2 finger breadth or 2 cm. above clavicular head,
trachea, sternocleidomastoid ms, & carotid sheath
palpated at level of cricoid cartilage
• 2 fingers press down at lat. Edge of transverse
process of C6, pushing the contents of carotid
sheath laterally
• A 1.5-3 in. 23 or 25 gauge B bevel needle is inserted
lat to trachea after skin inf. With local anesth.
• Transverse of C6 encountered between 2 fingers
withdraw needle 2 mm & inj 8-10 ml local
Stallate Ganglion
Stellate Ganglion Block
Question
• Stellate ganglion lies in closest proximity to
A. Common carotid artery.
B. Internal carotid artery.
C. Vertebral artery.
D. Axillary artery.
E. Aorta.
Answer ©
• The stellate ganglion usually lies in front of the
neck of the 1st rib. The vertebral artery lies
anterior to the ganglion as it has just
originated from the subclavian artery. After
passing over the ganglion, it enters the
vertebral foramen & lies posterior to the
anterior tubercle of C6.
Signs of successful block
•
•
•
•
Horner’s synd.
Ipsilateral nasal congestion
Flushing of conjunctiva & skin
Temperature increase in the ipsilateral arm &
hand
Side effects & complications
•
•
•
•
•
•
•
•
•
Lump sensation in throat
Hoarseness & dysphagia due to recurrent n block
Hematoma, osteitis
Brachial Plexus block
Phrenic nerve block
Epidural & subarachnoid block
Pneumothorax
Vertebral art. Inj. Causing loss of consciousness
Cardioaccelarator nerve block with hypotension
Follow up
Prognosis
• Some resolve with minimal management
• Most respond to initial conservative measure
• Early aggressive treatment in those with rapid
temporal changes has best results if initiated within
12 weeks of onset
• Prognosis poor if pain becomes chronic with
marked disability, thus emphasizing
multidisciplinary approach.