1. Quantify pathology

2. Support diagnosis

3. Follow-up natural history/treatment

4. Predict future pain

5. Predict response to therapy

1.Quantifying sensory function

Static pain parameters Thresholds

Non painful modalities Hypo (-)

Painful modalities

Hypo (-)

Hyper (+)

Quantifying sensory function

Static pain parameters

Non painful

neuropathyNeuropathic

pain

Non neuropathic

pain

Non painful modalities

Hypo (-)

Painful modalities

Hypo (-)

Hyper (+)

Quantifying sensory function

ThresholdsNon painful

Neuropathy

Neuropathic

pain

Non neuropathic

pain

Non painful modalities

Hypo (-)

Painful modalities

Hypo (-)

Hyper (+)

Pfau et al 2012

23 C6-7 Radic, 8 NS neck-arm pain, 22 FM & 31 ctrls

Wide QST battery at painful and contralateral sites

2 .Supporting diagnosis

Tampin et al, 2012

41 studies included PPT found most common QST 7 studies assessed session to session repeatability,

found quite good Estimated that 45 patients are needed to distinct OA

and ctrl groups for affected joint PPT

Staד

Suokas et al, 2012

Standardized Mean Differences compared to controls

Suokas et al, 2012

Pooled SMD (95% Conf.Int.)

Sequential QST on face for 10 wks 40 patients undergoing oral surgery No post surgical sensory complaints

Said-Yekta et al, 2012

Said-Yekta et al, 2012

Temporal summation (TS)

&

Conditioned pain modulation

(CPM, DNIC-like)

time

• Psychophysical response to repetitive stimuli Psychophysical response to repetitive stimuli expressed by expressed by

increased pain rating along stimulationincreased pain rating along stimulation

• Equivalent to Equivalent to ‘‘wind-upwind-up’’ in spinal WDR neurons in spinal WDR neurons

Pain rating

Sti

mulu

s in

tensi

ty

Sarlani & Greenspan,

2005

Rt Rt

Lt

CPM = ∆ VAS (VAS Post – VAS Pre)

Conditioned - pre Conditioned - post

Conditioning

VA

ST

emp

Efficient Less efficient

122 pre-operative patients

Nachmias et al 2009

CPM in IBS and TMD

Thoracotomy patients were:› Assessed for pain processing before

surgery, at pain-free time: Pain thresholds Pain60 CPM (DNIC), TS

› Undergone thoracotomy› Reported acute post-op pain (days 2 and

5) during: Cough Arm elevation

› Reported chronic post-op pain (6-12 month) During the week previous to clinic visit

TermOdds Ratio

(OR)

95% upper and lower OR

CPM (DNIC)0.500.28-0.79Baseline test-pain0.890.54-1.47

Acute pain1.861.29-2.98Pain threshold0.790.75-1.19

Surgery type [no rib #]0.620.28-1.30Gender [female]0.620.26-1.35

Age0.990.93-1.04

If pain modulation is involved in the generation of pain, it could also be involved in its alleviation› then

If less efficient CPM leads to development of pain, improving CPM in pain patients could lead to alleviation of pain

Pain assessed weekly, along: 1 baseline week 1 placebo week 1 week of 30 mg duloxetine 4 weeks of 60 mg duloxetine CPM, TS and other pain psychophysics at beginning and end.

CPM predicts efficacy of duloxetine in painful diabetic neuropathy

Yarnitsky et al, 2012

Less efficient CPM

GAIN !!!

Efficient CPM

NO GAIN

!!!

PredictorsB coefficients

Beta tP

Pre treatment depression

1.080.271.450.171

Initial spontaneous pain

0.290.241.030.321

Foot MDT5.530.160.740.475

Foot WDT-2.03-0.24-1.270.227

Placebo Effect-0.23-0.14-0.630.559

Pre treatment CPM

1.160.8224.200.001

1. Quantify sensory changes – positive and negative (vs. EMG)

2. Discern neuropathic from non neuropathic pain states

3. Be used for follow-up on changes in sensory state, such as after surgery

4. Predict post operative pain

5. Predict efficacy of pain alleviating agents

Iris Amor

Alon Sinai

Yelena Granovsky

Irit Weismann Fogel

David YarnitskyMichal Granot

Yonathan Crispel

Erica Dolnikov Liat Honigman Hadas AverbuchNachman

Ruth Moont

AndLab staff:Elliot SprecherDorit PudBeth MurrinsonRony NirRina Lev

Collaborators:Elon EisenbergRuth DefrinStefan LautenbacherEli EliavBob CoghillLars Arendt-NielsenOliver Wilder-SmithRami Burstein