changing the brain in pain - · pdf fileto map out the cortical homunculus in 1951 which is...
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CHANGING THE BRAIN IN PAIN
Investigating the Body Scan in MBCPMTM
BODY AWARENESS AND PAIN Zoom session December 16th 2015
Dr. Jackie Gardner-Nix, MB,BS., PhD., MRCP(UK)
Physician and Associate Professor
Dept. Anaesthesia, University of Toronto
Chronic Pain Consultant
St. Michael‟s Hospital Pain Clinic, Toronto
Getting Pain Sufferers back in touch with their Body
Body Scan Meditation
Loving Kindness Meditation
Mindful Movements Meditation
Guided Imagery
Do the practice of these change the
Somatosensory cortex?
Could they change Tactile Acuity?
Are they actively promoting Neuroplasticity?
Neuroplasticity 101 P O W E R P O I N T C O U R T E S Y O F : B A H R A M J A M ,
P T , O C T O B E R 3 , 2 0 1 5
Dr. Penfield, a pioneering neurosurgeon and a professor at McGill University, was the first person to map out the cortical homunculus in 1951 which is well known to us today: somatosensory and motor.
Dr. W Penfield 1951
Homunculus
Dr. Penfield suggested that the size of cortical representation also reflects kinesthetic proprioception, ...the body as felt in motion
The more you use a part of the body, the more present it
feels and the bigger the representation in the brain
Post injury, physiotherapists typically work hard at preventing loss of ROM and strength in their patients, but we need to equally focus on specifically preventing the loss of cortical representation by ... Focusing on awareness
Homunculus
Neuroplasticity
Consider this, infants can‟t make precise individual finger movements that they have not yet learnt ...therefore we may safely say, they have no awareness of their hands
Learned movements develop body awareness
Neuroplasticity
Michael Merzenich is a leading neuroscientist in the field of Neuroplasticity at the University of California, San Francisco and he says...
“Neuroplastic changes occur when the brain pays close attention while learning”
Merzenich MM, Van Vleet TM, Nahum M. Brain plasticity-based therapeutics. Front Hum Neurosci. 2014 Jun 27;8:385
Neuroplasticity
Tactile practice by reading Braille leads to an enlargement of the finger areas in the somatosensory cortex
Sterr, A., Green, L., Elbert, T. 2003: „Blind Braille readers mislocate tactile stimuli‟. Biol Psychol. 63(2), pp. 117-27.
Neuroplasticity
Clinical Relevance:
The more often we are aware and sense and move in a specific pattern, (touching, walking, throwing, sit to stand) the patterns get merged in the Homunculus
Neuroplasticity
Clinical Relevance:
The more often we move in a specific pattern, (walking, throwing, sit to stand) the pattern gets merged in the Homunculus.
This is positive if you are a violinist, golfer or a figure skater
Neuroplasticity
Clinical Relevance:
The more often we move in a specific pattern, (walking, throwing, sit to stand) the pattern gets merged in the Homunculus.
This is positive if you are a violinist, golfer or a figure skater
This is negative if you are limping for a prolonged period of time after a knee injury or not moving and guarding self due to persistent low back pain
Homunculus, tactile acuity and Mindfulness
Lorimer Moseley, PT, PhD has shown that “body image is disrupted, and tactile acuity is decreased, in the area of usual pain, in patients with chronic back pain.”
Moseley GL1. I can't find it! Distorted body image and tactile dysfunction in patients with chronic back pain Pain. 2008 Nov 15;140(1):239-43.
So How do we Evaluate Tactile Acuity?
2-point discrimination (2PD) may be used to evaluate the function of the primary somatosensory (S1) representation
2-point discrimination (2PD)
2PD can be measured using an inexpensive mechanical caliper
The tips of the caliper are applied until the very first blanching of the skin appears around the points.
2-point discrimination (2PD)
Testing begins by setting the caliper to 0 mm and gradually increasing the distance until the patient perceives two points instead of one
The patient is instructed to say „one‟, when one point was felt, „two‟, when two points are felt
2-point discrimination (2PD)
Once two is perceived, the caliper is slowly closed again until one is perceived again
The average of the two distances (Transition from two to one and from one to two) is considered the value for 2PD for that specific region
2-point discrimination (2PD)
2PD was developed and originally written about by a German physician EK Weber in 1834.
He is known as the father of sensory physiology and wrote the book “concerning touch” ...The two-point threshold, is the smallest distance between two points where a person determines that it is two points and not one
2-point discrimination (2PD)
2PD reflects the size and spacing of cutaneous receptive fields
2PD reflects the density of slowly adapting tactile axons
Why is Tactile Acuity Relevant?
The latest systematic review based on 16 studies concludes that tactile acuity is diminished in arthritis, CRPS, and chronic LBP...
....tactile acuity training may benefit those with chronic pain
disorders suggests that clinical trials may be warranted. Catley M..Moseley GL Is tactile acuity altered in people with chronic pain? a systematic
review and meta-analysis. J Pain. 2014 Oct;15(10):985-1000. Birklein F, Maihöfner C. Neglect your back to control your pain? Neurology. 2012 Jul
24;79(4):300-1. Mailis Gagnon A1, Keith N. The paradox of less sensation and more pain. Pain. 2012
Sep;153(9):1787-8.
Why is Tactile Acuity Relevant?
Why is Tactile Acuity Relevant?
The extent of tactile acuity impairment and the extent of cortical reorganization have been shown to directly relate to pain intensity in some conditions
Pleger B, P et al. Patterns of cortical reorganization parallel impaired tactile discrimination and pain intensity in complex regional pain syndrome. Neuroimage 2006;32:50310.
2PD & Painful Knee OA
2PD has been shown be larger in patients with painful knee OA
Asymptomatic (33mm+5mm)
Symptomatic (40mm+5mm)
Stanton TR…Moseley GL. Tactile acuity is disrupted in osteoarthritis but is unrelated to disruptions in motor imagery performance. Rheumatology (Oxford). 2013
Aug;52(8):1509-19.
2PD & Painful Knee OA
The reduced tactile acuity at the knee implies disturbed representation of the knee in the primary sensory cortex
Stanton TR…Moseley GL. Tactile acuity is disrupted in osteoarthritis but is unrelated to disruptions in motor imagery performance. Rheumatology (Oxford). 2013
Aug;52(8):1509-19.
2-point discrimination (2PD)
Normal values on asymptomatic population (kids & adults) has been researched for the hands, feet, face and even the tongue.
The normal values on the spine are quite variable
Cope EB1, Antony JH. Normal values for the two-point discrimination test. Pediatr Neurol. 1992 Jul-Aug;8(4):251-4
Vriens JP1, van der Glas HW. Extension of normal values on sensory function for facial areas using clinical tests on touch and two-point discrimination. Int J Oral
Maxillofac Surg. 2009 Nov;38(11):1154-8.
TPD was assessed at the neck, back, hand and foot. Mean TDP
thresholds measured in 28 healthy subjects are reported for each of
the four locations assessed.
Mark J. Catley et al. Rheumatology 2013;52:1454-1461 © The Author 2013. Published by Oxford University Press on behalf of the British Society for
Rheumatology. All rights reserved. For Permissions, please email:
Some researchers have discussed the pitfalls and limitations of 2PD and suggest 2POD to be a more accurate measure of tactile acuity
For 2POD the patient must discriminate the orientation (horizontal vs. vertical) of two points of contact
2-Point Orientation Discrimination (2POD)
Tong J1, Mao O, Goldreich D. Two-point orientation discrimination versus the traditional two-point test for tactile spatial acuity assessment. Front Hum Neurosci.
2013 Sep 13;7:579.
2POD is proposed to provide a more accurate measure spatial acuity
2-Point Orientation Discrimination
Tong J1, Mao O, Goldreich D. Two-point orientation discrimination versus the traditional two-point test for tactile spatial acuity assessment. Front Hum Neurosci.
2013 Sep 13;7:579.
I don‟t know where it is!
Patients with chronic neck & back pain have been shown to have reduced proprioceptive acuity
Brumagne S, et al. The role of paraspinal muscle spindles in lumbosacral position sense in individuals with and without low back pain. Spine 2000;25: 989–94.
Harvie DS et al Neck Pain and Proprioception Revisited Using the Proprioception
Incongruence Detection Test. Phys Ther. 2015 Sep 24.
Low Back Pain (LBP)
People with chronic LBP have been shown to have markedly different cortical representation of their back when compared to healthy controls
Flor H, et al Extensive reorganization of primary somatosensory cortex in chronic back pain patients. Neurosci Lett 1997;224:5–8.
.
Patients with chronic LBP have also been shown to have a disruption of their body schema of their trunks as they have difficulty identifying images involving left versus right trunk rotation
Bray H1, Moseley GL. Disrupted working body schema of the trunk in people with back pain. Br J Sports Med. 2011 Mar;45(3):168-73.
I can’t find it! Distorted body image and tactile dysfunction in patients with
chronic back pain
Lorimer Moseley
Moseley GL1. I can't find it! Distorted body image and tactile dysfunction in patients with chronic back pain Pain. 2008 Nov 15;140(1):239-43.
Body part neglect/subconscious avoidance?
Two Point Discrimination & Chronic Low Back Pain
Patients with Chronic LBP were instructed to complete a drawing of their back. They were instructed “Concentrate on your back, draw the outline of your back as you track it in your mind. Concentrate in where you feel your back to be.”
Moseley GL1. I can't find it! Distorted body image and tactile dysfunction in patients with chronic back pain Pain. 2008 Nov 15;140(1):239-43.
2PD & CLBP
The patients given this task had difficulty completing the simple act of drawing an outline of their back, reporting
“I can’t find it”
“It feel as though my back has shrunk”
Is this happening in early body scan meditations?
Moseley GL1. I can't find it! Distorted body image and tactile dysfunction in patients with chronic back pain Pain. 2008 Nov 15;140(1):239-43.
2PD & CLBP
The patients also demonstrated decreased tactile acuity (2PD) at the level and side of their back pain
2PD in low back is generally 50mm but on the side and level of pain it increased to 75mm
Moseley GL1. I can't find it! Distorted body image and tactile dysfunction in patients with chronic back pain Pain. 2008 Nov 15;140(1):239-43.
Why Measure 2PD?
Cortical reorganization and altered tactile acuity are both associated with chronic pain conditions including osteoarthritis
Clinicians can reliably assess 2PD thresholds using calipers
Catley MJ...Moseley GL. Assessing tactile acuity in rheumatology and musculoskeletal medicine--how reliable are two-point discrimination tests at the neck, hand, back and
foot? Rheumatology (Oxford). 2013 Aug;52(8):1454-61
There is certainly evidence that persistent pain is associated with changes in the somatosensory cortex disrupting cortical representation of the painful body area
Gustin SM, et al Pain and plasticity: is chronic pain always associated with somatosensory cortex activity and reorganization? J Neurosci 2012, 32(Suppl
43):14874–14884.
There is now growing evidence that patients with CLBP also have distorted cortical representation of the sensorimotor area representing the low back
Moseley L, Flor H: Targeting cortical representations in the treatment of chronic pain: a review. Neurorehabil Neural Repair 2012, 26(Suppl 6):646–652.
Wand BM, et al: Tactile thresholds are preserved yet complex sensory function is impaired over the lumbar spine of chronic non-specific low
back pain patients: a preliminary investigation. Physiotherapy 2010, 96:317–323.
Flor H, Braun C, Elbert T, Birbaumer N: Extensive reorganization of primary somatosensory cortex in chronic back pain patients. Neurosci Lett 1997,
224:5–8.
In patients with CLBP, the representation of the back has been shown to be shifted by about 2cm in the somatosensory cortex
Flor H, Braun C, Elbert T, et al. Extensive reorganization of primary somatosensory cortex in chronic back pain patients. Neurosci Lett 1997; 224 : 5 – 8 .
Somatosensory reorganization distorts the cortical body map that the brain relies on to execute movement
This distortion causes incompatibility between motor commands and sensory feedback …which may produce pain!
Moseley GL1, Zalucki NM, Wiech K. Tactile discrimination, but not tactile stimulation alone, reduces chronic limb pain. Pain. 2008 Jul 31;137(3):600-8.
It is hypothesized that the cortical changes contribute to pain maintenance
Therefore interventions to “normalize” cortical representation are being developed and researched
Moseley L, Flor H: Targeting cortical representations in the treatment of chronic pain: a review. Neurorehabil Neural Repair 2012, 26(Suppl 6):646–652
By reversing the cortical distortion, the motor commands become once again compatible with the sensory feedback, …voila no pain!
Moseley GL1, Zalucki NM, Wiech K. Tactile discrimination, but not tactile stimulation alone, reduces chronic limb pain. Pain. 2008 Jul 31;137(3):600-8.
Tactile Acuity Training
Tactile acuity training has been shown to be effective in patients with phantom limb pain and CRPS resulting in pain reduction and cortical reorganization of the body area as seen on fMRI
Flor H, et al: Effect of sensory discrimination training on cortical reorganisation and phantom limb pain. The Lancet 2001, 357:1763–1764 Moseley L, Zalucki NM, Wiech K: Tactile discrimination, but not tactile
stimulation alone, reduces chronic limb pain. Pain 2008, 137:600–608.
Tactile Acuity & Chronic Low Back Pain
Four studies have shown that tactile acuity is reduced in people with CLBP with 2PD being larger by up to 2cm
In those with unilateral LBP, 2PD is larger on the painful side
There appears to be no association between pain intensity or pain duration and tactile acuity in acute LBP
Catley MJ, O‟Connell NE, Berryman C, Ayhan FF, Moseley GL (2014) Is tactile acuity
altered in people with chronic pain? A systematic review and meta-analysis J Pain. pii: S1526-5900(14)00792-5
Tactile Acuity & CLBP
Although tactile acuity can be evaluated relatively easily using 2PD test, the challenge is how do we know what is normal and what is not?
The studies on healthy and patients with CLBP show a wide variability in 2PD values
Again, what is normal 2PD? What is abnormal 2PD? We need to know what is normal within each individual.
Wand BM…Moseley GL2. Lumbar tactile acuity is near identical between sides in healthy pain-free participants. Man Ther. 2014 Oct;19(5):504-7.
Tactile Acuity & CLBP
There is minimal difference (2-5mm) between sides in healthy backs
Therefore, in people with unilateral CLBP the non-painful side may be used as reference value when assessing 2PD on the painful area
Wand BM…Moseley GL2. Lumbar tactile acuity is near identical between sides in healthy pain-free participants. Man Ther. 2014 Oct;19(5):504-7.
Tactile Acuity & CLBP
A 2PD difference between sides may be considered significant if it is greater than 13 mm when assessed horizontally
Wand BM…Moseley GL2. Lumbar tactile acuity is near identical between sides in healthy pain-free participants. Man Ther. 2014 Oct;19(5):504-7.
Tactile Acuity & CLBP
A 2PD difference between sides may be considered significant if it is greater than 17 mm when assessed vertically
Wand BM…Moseley GL2. Lumbar tactile acuity is near identical between sides in healthy pain-free participants. Man Ther. 2014 Oct;19(5):504-7.
Tactile Acuity & CLBP
Greater 2PD has been associated with poorer voluntary lumbo-pelvic control
Wand BM…Moseley GL2. Lumbar tactile acuity is near identical between sides in healthy pain-free participants. Man Ther. 2014 Oct;19(5):504-7.
Tactile Acuity & CLBP
It is suggested that tactile discrimination training may improve motor control and proprioception in patients with CLBP
Wand BM…Moseley GL2. Lumbar tactile acuity is near identical between sides in healthy pain-free participants. Man Ther. 2014 Oct;19(5):504-7.
Tactile Acuity & CLBP
Wand BM…Moseley GL2. Lumbar tactile acuity is near identical between sides in healthy pain-free participants. Man Ther. 2014 Oct;19(5):504-7.
Tactile Acuity & CLBP
It has been shown that discriminating the location and the size of the tactile stimuli on a body part can decrease pain and improve 2PD
Why?
Moseley GL1, Zalucki NM, Wiech K. Tactile discrimination, but not tactile stimulation alone, reduces chronic limb pain. Pain. 2008 Jul 31;137(3):600-8.
Tactile Acuity & CLBP
Mindful exposure to non-painful stimuli may be the reason for the reduction of pain
Moseley GL1, Zalucki NM, Wiech K. Tactile discrimination, but not tactile stimulation alone, reduces chronic limb pain. Pain. 2008 Jul 31;137(3):600-8.
Acupuncture & Neuroplasticity
Patient with CLBP were randomly assigned to two needling groups but both patient groups received the same number of needles, in the same points, inserted to the same depth and with an identical type and amount of needle manipulation
Wand BM1, … Moseley GL. Acupuncture applied as a sensory discrimination training tool decreases movement-related pain in patients with chronic low back pain more
than acupuncture alone: a randomised cross-over experiment. Br J Sports Med. 2013 Nov;47(17):1085-9.
Acupuncture & Neuroplasticity
The only difference was that the patients in the control group were asked to relax and not focus on the needles
Wand BM1, … Moseley GL. Acupuncture applied as a sensory discrimination training tool decreases movement-related pain in patients with chronic low back pain more
than acupuncture alone: a randomised cross-over experiment. Br J Sports Med. 2013 Nov;47(17):1085-9.
Acupuncture & Neuroplasticity
On the other hand the patients in the experimental group were instructed to consciously focus on the location of each needle and be aware when a needle was moved ... they were to refer to an image and estimate the position of each needle
Wand BM1, … Moseley GL. Acupuncture applied as a sensory discrimination training tool decreases movement-related pain in patients with chronic low back pain more
than acupuncture alone: a randomised cross-over experiment. Br J Sports Med. 2013 Nov;47(17):1085-9.
Acupuncture & Neuroplasticity
Compared to the patients who received “passive needling”, those in the “mindfulness needling” reported immediately less pain with movement
Wand BM1, … Moseley GL. Acupuncture applied as a sensory discrimination training tool decreases movement-related pain in patients with chronic low back pain more
than acupuncture alone: a randomised cross-over experiment. Br J Sports Med. 2013 Nov;47(17):1085-9.
Acupuncture & Neuroplasticity
Perhaps sometimes acupuncture might help people with back pain by improving self-perception and awareness of the back
Wand BM1, … Moseley GL. Acupuncture applied as a sensory discrimination training tool decreases movement-related pain in patients with chronic low back pain more
than acupuncture alone: a randomised cross-over experiment. Br J Sports Med. 2013 Nov;47(17):1085-9.
Acupuncture & Neuroplasticity
Perhaps needling a painful area improves symptoms through a sensory discrimination like effect
Wand BM1, … Moseley GL. Acupuncture applied as a sensory discrimination training tool decreases movement-related pain in patients with chronic low back pain more
than acupuncture alone: a randomised cross-over experiment. Br J Sports Med. 2013 Nov;47(17):1085-9.
Acupuncture & Neuroplasticity
“…acupuncture may offer specific benefit that is not dependent on precisely where the needles are inserted so much as that the patient attends to where they are inserted.”
Wand BM1, … Moseley GL. Acupuncture applied as a sensory discrimination training tool decreases movement-related pain in patients with chronic low back pain more
than acupuncture alone: a randomised cross-over experiment. Br J Sports Med. 2013 Nov;47(17):1085-9.
Tactile Acuity Training & Chronic LBP
A case series study was done to investigate the potential effects of tactile acuity training on three patients with chronic LBP
Wand BM, et al: Managing chronic nonspecific Low back pain with a sensorimotor retraining approach: exploratory multiple-baseline study of 3 participants. Phys Ther
2011, 91(Suppl 4):535–546
Tactile Acuity Training & Chronic LBP
The 3 patients had all been through multiple failed past treatments such a PT, Chiro, Pilates, Yoga, nerve block and narcotics
Wand BM, et al: Managing chronic nonspecific Low back pain with a sensorimotor retraining approach: exploratory multiple-baseline study of 3 participants. Phys Ther
2011, 91(Suppl 4):535–546
Tactile Acuity Training & Chronic LBP
They attended twice a week for 8 weeks for one hour sessions and were to do daily home exercises with the assistance of a family member for 30 minutes, 3 times a day
Wand BM, et al: Managing chronic nonspecific Low back pain with a sensorimotor retraining approach: exploratory multiple-baseline study of 3 participants. Phys Ther
2011, 91(Suppl 4):535–546
Tactile Acuity Training & Chronic LBP
All 3 patients greatly benefitted from the 10 weeks of daily tactile acuity training ; two
ended up with zero pain! (Note: They also received
pain education and gentle motor control training)
Wand BM, et al: Managing chronic nonspecific Low back pain with a sensorimotor retraining approach: exploratory multiple-baseline study of 3 participants. Phys Ther
2011, 91(Suppl 4):535–546
The latest systematic review based on 16 studies concludes that tactile acuity is diminished in arthritis, CRPS, and chronic LBP…
The extend of tactile acuity impairment and the extent of cortical reorganization have been shown to directly relate to pain intensity in some conditions
Pleger B, P et al. Patterns of cortical reorganization parallel impaired tactile discrimination and pain intensity in complex regional pain syndrome. Neuroimage 2006;32:50310.
Catley M..Moseley GL Is tactile acuity altered in people with chronic pain? a systematic review and meta-analysis. J Pain. 2014 Oct;15(10):985-1000.
Birklein F, Maihöfner C. Neglect your back to control your pain? Neurology. 2012 Jul 24;79(4):300-1.
Mailis Gagnon A1, Keith N. The paradox of less sensation and more pain. Pain. 2012 Sep;153(9):1787-8.
Remember: Why is Tactile Acuity Relevant?
Body scan in a participant with sensory loss:
The following case study showed the benefits of Body Scan in a patient with sensory loss due to neck surgery, which resulted in profound head pain, so severe she was on opioids and adjuvants to try to control the pain for 2 years before entering the MBCPMTM course.
She participated in the MBCPMTM course from Barrie, Ontario with the facilitator at Sunnybrook HSC in Toronto
Cheryl’s Story of Head Pain
Cheryl in her 30s, had intolerable head pain and loss of sense
of touch below mid chest after surgery for a rare condition.
Initially she was in a wheelchair and was in rehabilitation to
relearn to walk.
High doses of opioids would only temporarily control her
pain. Over the next 2 years she was in agony, while opioid
rotations, anticonvulsants, anti-depressants, and muscle
relaxants were tried.
She was on oxygen, walked with a walker and had attendant
care funded by the Province of Ontario.
Cheryl’s creative work
She attended MBCPMTM via
telemedicine to her home town,
during which she drew this picture
of her pain.
She meditated daily, gradually
reduced her medications, still
staying on a low dose, and 3 years
later, returned to her job in the auto
factory where she had originally
worked.
Meditating with the Body Scan
daily was the main way she
controlled her pain.
Cheryl‟s Pain Management
Body scan kept her at 4/10 in pain intensity
Had to be done daily
Its effectiveness was likely related to her loss of touch acuity with the sensory loss
Allowed pain reduction so reduced medication---
Which reduced hyperalgesia from the medication
MBCPMTM allowed clarity to: Change her toxic
psychosocial circumstances which she recognized contributed to her pain
While still on some opioid she was able to return to work at her factory after 5 years on disability
Body scan would also allow increased proprioception for safety.
“Patterning” in Polio
In the epidemics of polio in the early 1900s children recovering from paralysis would have teams of volunteers and family members come, in shifts, to move their legs for them, called “patterning”, until they could move them by themselves.
This is an example of the mind/body disconnect.
Awareness, assisted by movement, reconnects those neural pathways and trains the mind to move the neglected body again.
Could Body Scan, and Loving Kindness meditations have more applications than at first realized?
Formal Practice
Body Scan is a visualization which brings back awareness and recognition
Loving Kindness toward self enhances and strengthens the practice
Mindful Movement Meditation, or Yoga done mindfully, brings back recognition and awareness by using movement and proprioception
All strengthen the mind body connection and, by synchronizing
movement with sensation and proprioception, may enhance safe,
well coordinated, movement, reducing pain and injury.