Acupuncture for Neuropathic Pain

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Acupuncture for Neuropathic Pain

• The University Health Network
• Interdisciplinary Pain Conference
• Emerging Practices in Pain Management
• February 27, 2007
• Linda M. Rapson MD, CAFCI

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Introduction of Acupuncture into Toronto
Rehabilitation Institute Lyndhurst Centre

• Pilot Project 1992-93
• Part of physiotherapy program since 1993
• Over 300 patients treated 1992-99
• Traumatic non-traumatic spinal cord injured
  inpatients treated for acute chronic pain
• Referred by staff physiatrists (PMR)
• Paper presented at ASIA meeting, 1995 77 Good
  to Excellent outcomes (N 61)

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Acupuncture as a Promising Treatment for
Below-level Central Neuropathic Pain A
Retrospective Study

• Linda M. Rapson MD, CAFCI1, 2, 3, Nancy Wells
  BPT, CAFCI1,
• Jennifer Pepper BScPT, CAFCI1, Nadine Majid BSc4,
  and Heather Boon PhD4
• 1Toronto Rehabilitation Institute, Lyndhurst
  Centre
• 2Acupuncture Foundation of Canada Institute
• 3 Rapson Pain and Acupuncture Clinic, Toronto
• 4Faculty of Pharmacy, University of Toronto

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Rapson LM, Wells N, Pepper J, Majid N, Boon H.
Acupuncture as a promising treatment for
below-level central neuropathic pain a
retrospective study. J Spinal Cord Med. 2003
Spring26(1)21-6
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Below-level Neuropathic pain in SCI

• Diffuse Pain
• "burning"
• "tingling"
• "aching"
• "shooting"
• "stabbing
• Present at least 3 segments below SCI level
• Usually continuous

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The Lyndhurst Centre Central Neuropathic Pain
Acupuncture Protocol (LCCNPAP)

• GV 18, 20, 21, 24.5 (Yintang)
• Insert at shallow angle along meridian
• Posterior to anterior
• Electrical stimulation 30 minutes _at_ 1 Hz
• 5 treatments per week (initially)
• Decrease as effects become cumulative
• Add other acupuncture approaches prn

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Review of CNP Outcomes TRILC Acupuncture Clinic
1994-99

• All cases with deafferentation pain diagnosis
  reviewed
• Term used to identify below-level central
  neuropathic pain prior to 1997 and in TRILC
  charts until 1999

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Inclusion Criteria

• Below-level generalized burning pain
• LCCNPAP was first acupuncture intervention
• Note patients were allowed to continue pain
  medications

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Information from chart review

• Demographics
• Age, Sex
• SCI Characteristics
• Level of injury, ASIA (American Spinal Injury
  Association) impairment score, complete/incomplete
  injury, cause of SCI, date of injury
• Pain symptoms
• Date of onset, duration before acupuncture Rx,
  character of pain (temporal pattern,
  distribution)
• Outcomes
• VAS, of Rxs, of Rxs before first
  improvement
• Adverse effects

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Pain Scale Ratings

• 11 point Visual Analogue Scale (VAS)
• 0 no pain 10 most pain imaginable
• Rated
• at time of first acupuncture Rx
• before and after each acupuncture Rx
• Compared pain levels at first visit with
  discharge levels

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Accuracy of pain characteristic data

• Two authors independently examined chart
  information
• Identified pain characteristics that applied to
  each patient
• Disagreements resolved by third investigators
  independent review of raw data
• Significance of plt0.05 set for Chi-square
  statistical analysis

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Participants (N 36)

• 23 Men
• 13 Women
• Age range 17 - 75
• Duration of pain 2 weeks to 15 years

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Levels of SCI

• C4 to Cauda Equina

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Causes of SCI N 36

• Trauma
• Post Surgery
• Multiple Sclerosis
• Guillain-Barré Syndrome
• Transverse Myelitis
• Cervical Myelopathy/Syringomyelia
• Chronic Inflammatory Demyelinating Polyneuropathy
• Arteriovenous Malformation
• Syringomyelia/Arachnoiditis
• Limbic Paraneoplastic Encephalomyelitis
• Congenital lumbar hemivertebrae

• 22
• 2
• 3
• 1
• 1
• 1
• 1
• 2
• 1
• 1
• 1

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Number of Treatments Before First Improvement N
36 Patients
Treatments 1 2 3 4
Patients 18 50 4 11 1 3 1
3 24 67
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Number of treatments

• No one in this group improved if they did not get
  a response by the 4th treatment
• Prospective data since 1999 included some who
  started to respond after 6-10 treatments

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Factors and pain characteristics related to
improvement?

• Duration of pain
• Level of injury, ASIA scale
• Pattern of pain
• Constant vs. intermittent pain
• Burning vs. burning atypical pain
• Symmetrical vs. asymmetrical pain
• Bilateral vs. unilateral pain

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Outcome was not related to

• Level of SCI
• Duration of symptoms
• Cases with 15 years and 15 years of pain
  responded to first Rx
• ASIA impairment score
• Complete/incomplete injury

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Bilateral Vs Unilateral
P 0.014
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Symmetric Vs Asymmetric
P 0.026
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Burning Vs Burning Atypical
P 0.138 Not significant
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Constant vs. Intermittent
P 0.173 Not significant
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Bilateral/Symmetric Vs Unilateral or Asymmetric
P 0.006
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Bilateral/Symmetric/Burning/Constant Vs
Unilateral or Asymmetric or Atypical or
Intermittent
P 0.005
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Adverse Effects

• 0

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Specifically,

• No bruising or bleeding in spite of
  anticoagulants
• No autonomic dysreflexia (potentially fatal
  hyperreflexia of the ANS in SCI)
• No syncope, in spite of treating many patients
  while seated in wheelchairs

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Limitations of this review

• Not blinded or controlled
• Incomplete data for some patients
• Inconsistencies in number of treatments
• Use of VAS alone to define improved group not
  possible because of inconsistencies

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However,

• Response often prompt 50 to first Rx
• Response often dramatic
• Many had suffered pain resistant to other
  treatment protocols for long periods

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Dr. Ronald Tasker, NeurosurgeonUniversity of
Toronto

• During stereotactic mapping of the brain,
  patients with deafferentation pain were four
  times more likely than patients with nociceptive
  pain to show a somatosensory response in planes
  medial to the 8 mm sagittal plane

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• If deafferentation pain is due to lack of
  afferent input from injured nerves or spinal
  cord, are we merely filling the gap centrally
  with our midline scalp stimulation with
  electro-acupuncture?

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Treating Non-SCINeuropathic Pain with LCCNPAP

• Post nerve injury pain (e.g. dental)
• Post Herpetic Neuralgia
• Burning tongue syndrome
• Burning perineal pain
• Longstanding RSD/CRPS
• Central Pain
• Etc

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• Anecdotally, amitriptyline is synergistic with
  acupuncture
• (10 mg)

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Change in Protocol

• Based on research of Dr. J.S. Han
• Start with 100 Hz frequency for 10 minutes
• Note response pain should decrease
• Switch to 2 Hz for 10-20 minutes
• Or use 2/100 Hz combination
• Try this on failures of 1 Hz treatment