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Joseph L Riley III, PhD | Pain & Aging Pre-Conference Workshop. DISCLOSURE. I have no relevant commercial relationships to disclose. Assessing Pain Modulation in Older Adults. Topics. Pain modulation 101 Why older adults? Laboratory tests of pain modulation. Tissue damage
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Joseph L Riley III, PhD | Pain & Aging Pre-Conference Workshop.
DISCLOSURE I have no relevant commercial relationships to disclose.
Assessing Pain Modulation in Older Adults Topics • Pain modulation 101 • Why older adults? • Laboratory tests of pain modulation
Tissue damage • Protective • Acute vs. Prolonged • Chronic pain (beyond normal healing?) Pain is adaptive
IOM Report: June 29, 2011 “Chronic pain ….. surpasses its underlying cause to become a disease in its own domains and dimensions.” “Changes in structure and function of the nervous system”
How does modulation become dysfunctional? Central Sensitization • Increased sensitivity • Increased CNS excitability • Enlargement of receptive fields • CNS activity that outlast the trigger Loss of descending inhibition
Pain psychophysics Laboratory (noxious stimuli) • Single end-points • Dynamic tests of pain modulation
Chronic pain populations • Increased sensitivity • Enhanced facilitation • Reduced inhibition
Temporal summation (facilitatory) Animal studies • Short rapid stimulation • C-fiber specific • Interval sensitive • Spinal mechanism
Age differences in temporal summation Testing parameters: • SI: 0.8-sec • ISI: 2.5-, 3.5-, 4.5-sec • Individualized temperature Participants: • 88 Younger adults (ages 18-39) • 48 Middle-aged (40-59) • 62 Older adults (60-80)
p=.04 p=.01 P<.001
p=.04 p=.01 P<.001
p=.04 p=.01 P<.001
Rated the size percept of the pain Naugle KM, Cruz-Almeida Y, Fillingim RB, Staud R, Riley JL 3rd. Increased spatial dimensions of repetitive heat and cold stimuli in older women. Pain. 2017 May;158(5):973-979
Response to prolonged stimuli Participants: • 36 Younger adults (18-36) • 28 Older adults (55-78) Thermal heat at individualized temperature (Pain40)
Additional sensitization for the older adults during trial 4
Older adults show greater pain facilitation • Temporal summation - short acting • Spatial spreading of pain • Prolonged stimulation - over 60-min
Pain-inhibits-pain model Conditioning stimulus Conditioned Pain Modulation (CPM)
Pain-inhibits-pain model • Established in animal models • Heterotopic • Reduced with naloxone Test stimulus Conditioned Pain Modulation (CPM)
Conditioned pain modulation Participants: • 27 Younger adults (20-44) • 24 Older adults (56-78) Riley JL 3rd, King CD, Mauderl AP, Wong F, Fillingim RB. Differences in pain sensitivity and modulation across the lifespan. Pain. 2010 Jul;150(1):153-160.
Pain modulation becomes dysfunctional Central Sensitization • Increased sensitivity (120-s) • Increased CNS excitability (TS) • Enlargement of receptive fields (TS size) • CNS activity that outlast the trigger (After sensations) Loss of descending inhibition (CPM)
Inhibition Is the balance tipped for older adults? Facilitation
Restore loss of adaptive pain modulation Plasticity of the CNS • Changes in diet • Exercise • Reduction of stress • Positive thinking
UF Pain Research and Intervention Center of Excellence (PRICE) Roger B. Fillingim, PhD Charles J. Vierck, PhD Roland Staud, MD Patrick Tighe, MD Andre P. Mauderli, DMD, PhD Yenisel Cruz-Almeida, MSPH, PhD Kelly M. Naugle, PhD Shannon M. Wallet, PhD Nathan Eckert, PhD Corey Simon, DPT, PhD and many UF students
Future directions • Exercise restores cognitive functioning • Exercise programs reduce pain for many pain conditions
14-week program of light cycling and stretching Preliminary data from 9 participants ages 55-74
Following the exercise program Reduced summation
UF Pain Research and Intervention Center of Excellence (PRICE) Roger B. Fillingim, PhD Charles J. Vierck, PhD Roland Staud, MD Patrick Tighe, MD Andre P. Mauderli, DMD, PhD Yenisel Cruz-Almeida, MSPH, PhD Kelly M. Naugle, PhD Shannon M. Wallet, PhD Nathan Eckert, PhD Corey Simon, DPT, PhD and many UF students