on chronic neuropathic pain

37 Pages·2012·0.74 MB·English

BEST (BIOFEEDBACK ELECTRO-STIMULATION
THERAPY) ON CHRONIC NEUROPATHIC PAIN: EFFECTS
ON PAIN SCORE AND PAIN BIOMARKER NITRIC OXIDE

LEE ZHI SHAN

FACULTY OF MEDICINE
UNIVERSITY OF MALAYA
KUALA LUMPUR
2014
ABSTRACT
Background: Treatment of chronic pain has incorporated both pharmacotherapy and
non-pharmacotherapy in view of the complexity of the nature of the pain. Avazzia
BEST-RSI has been introduced as the latest innovation in the TENS-like technology in
treating chronic pain. This study aims to determine the effects of its treatment on
chronic neuropathic pain patients and the likely mechanism of action via nitric oxide.

Method: This is a prospective single blinded randomised controlled study involving 20
patients from the Pain Clinic, University Malaya Medical Centre between 1st January
2014 and 31st June 2014. The patients were randomised to treatment and placebo arm.
Measured outcomes were visual analogue score and serum nitric oxide level before and
after treatment. Data was analysed using SPSS version 20 and the level of significance
was set at p<0.05.

Results: Baseline demographics, diagnosis and treatment modalities on both arms were
similar. Pain score reduction post treatment in the Avazzia BEST-RSI group was
significantly more (median of 7.5 to 3.5, p=0.005) compared to the placebo group
(median of 5 to 4.5, p=0.039). The level of nitric oxide increased after Avazzia BEST-
RSI treatment (median 5.7μM to 6.65µM, p=0.386) as compared to a drop in the
placebo group (median 4.7μM to 3.7μM, p=0.202). Half of the patients in the treatment
group felt that the treatment was effective versus only 30% patients in the placebo
group.

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Conclusion: Avazzia BEST-RSI demonstrated better pain reduction and an increase in
the serum nitric oxide level. It is therefore effective in treatment of chronic neuropathic
pain after one single treatment and may be potentially effective in the long term
management as well.

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TABLE OF CONTENTS
Page
Chapter 1: Introduction 1
Chapter 2: Materials and Methods/ Methodology
2.1 Sample size 4
2.2 Inclusion and exclusion criteria 4
2.3 Randomisation 5
2.4 Intervention
2.4.1 Avazzia BEST RSI 5
2.4.2 Placebo 6
2.5 Study protocol 6
2.6 Statistical Analysis 7
Chapter 3: Results 8
Chapter 4: Discussion 13
Chapter 5: Conclusion 16
References 17
Appendix 20

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LIST OF FIGURES
Page
Figure 3.1: Patients’ global satisfaction 12
Figure 3.2: Patients’ willingness to try the treatment again 12

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LIST OF TABLES
Page
Table 3.1: Patient Baseline Demographic Characteristics 8
Table 3.2: Patient Diagnosis and Treatment Modalities 9
Table 3.3: Effects on Pain Score 10
Table 3.4: Effects on Nitric Oxide 11

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LIST OF SYMBOLS AND ABBREVIATIONS
BEST Biofeedback Electro Stimulation Technology
FDA Food and Drug Administration
IASP International Association for the Study of Pain
μM micromole
N Number
RSI Repetitive Strain Injury
TENS Transcutaneous Electrical Nerve Stimulation
SD Standard deviation
UMMC University Malaya Medical Centre

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CHAPTER 1: INTRODUCTION
The International Association for the Study of Pain (IASP) defines pain as an
unpleasant sensory and emotional experience associated with actual or potential tissue
damage or described in term of such damage (1).

Acute pain is defined as pain of recent onset and probable limited duration. It usually
has an identifiable temporal and causal relationship to injury or disease. Chronic pain
however commonly persists beyond the time of healing of an injury and frequently there
may not be any clearly identifiable cause (2). Arbitrarily the duration has been taken as
more than 3 months.

Neuropathic pain has been defined by IASP as pain initiated or caused by a primary
lesion or dysfunction in the nervous system (3). It usually causes chronic symptoms.
The mechanisms for neuropathic pain and its treatment differ from nociceptive pain (4).
In the periphery, the threshold for activation of injured primary afferents is lowered and
ectopic discharges may arise from the injury site or the dorsal root ganglion due to
changes in the sodium channel expression. Within the spinal cord, the increased
peripheral input induces central sensitization. Loss of inhibitory mechanisms, reparatory
processes in damaged nerves and reactive changes in adjacent tissues (particularly glial
cells and immune cells) may further increase central excitability. Functional (altered
neurotransmitter expression) and anatomical (sprouting into superficial laminae in the
dorsal horn) changes in A-beta fibres contribute to the tactile allodynia (pain induced by
light touch) that is a frequent feature of neuropathic pain.

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Symptoms of neuropathic pain can be positive and negative sensory symptoms (4).
Positive symptoms such as dysthesias and paraesthesia are common. Stimulus
independent pain maybe intermittent (shooting, lancinating or electric shock light) or
continuous (superficial or deep pressure). Stimulus-evoked pain results from chemical,
thermal or mechanical stimuli and is characterized by allodynia and hyperalgesia. In
addition, most patients may experience co-existing negative sensory symptoms such as
loss or impairment of sensory quality, numbness and reduced sensation.

The definition of pain underlies the complexity of its measurement. Pain is an
individual and subjective experience modulated by psychological, physiological and
environmental factors. Therefore most measures of pain are based on self-report. These
measures lead to sensitive and consistent results if done properly (5). A number of
scales are available such as categorical scales and numerical rating scales. Categorical
scales use words to describe the magnitude of pain and have the advantage of being
quick and simple and especially useful for elderly, children and visually impaired.
However the limited number of choices may make it more difficult to detect differences
(6). Numerical rating scales such as visual analogue score and verbal numerical rating
scales are simple and quick and allow for a wide choice of ratings and avoid imprecise
descriptive terms (7). However, the scales need concentration and coordination and may
not be suitable for children below 5 and 26% of adult (8).

Management of chronic neuropathic pain includes pharmacotherapy, physical therapy,
occupational therapy, psychological therapy, interventional therapy and complementary
therapy. Biofeedback electro-stimulation therapy (BEST) devise is the latest generation
of peripheral electro-stimulation device. It is FDA approved for symptomatic relief and
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management of chronic, intractable pain and adjunctive treatment in the management of
post-surgical and post-traumatic pain. BEST generates electrical impulses (sine waves)
that are physiologically similar to neurological impulses observed in the ‘C’ nerve
fibres and ‘A’ fibres. Electrical signal characteristics of BEST are short duration pulses
of high voltage amplitude and very low duty cycle, average currents in microcurrent
range and damped bi-phasic sinusoidal waveforms.

The device seeks decreased impedance on skin by ‘sticking’ to acupuncture or electron
deficient points when gliding over the skin. This area may comprise of injured or
diseased tissue or may be associated with an organ or corresponding structure with that
anatomical segment. The device then communicates the electrical impulse with the
neuro-endocine system through direct contact to the skin, sending signal through the
epidermis and dermis to the ‘A’ and ‘C’ fibres. The nervous system then releases nitric
oxide, endorphins and neuropeptides. Nitric oxide causes vascular dilation and increase
blood circulation. Endorphin and neuropeptides are natural pain management chemicals
that also promote healing. The process is the further enhanced by signals that change
and adapt as the electrical properties of the tissue that is being treated change.

Advantage of the BEST devise include quick relief from acute and chronic pain, pain
relief of up to 12 hours, and asymmetrical wave signals and biofeedback that minimizes
habituation and accommodation effects of the body.

This study aims to use Avazzia BEST device on chronic neuropathic pain and evaluate
the changes in perceived levels of pain and changes in nitric oxide.
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