Effects of aging on contact heat‐evoked potentials: The physiological assessment of thermal perception

Abstract

Age significantly influences the detection thresholds to noxious heat; such thresholds depend on responses in the cerebral cortex to thermal stimuli and the psychophysical perception of such responses. To understand the influence of age on cerebral responses, we used contact heat-evoked potentials (CHEPs) to investigate the physiology of cerebral responses to thermal stimuli in 70 healthy subjects (33 men and 37 women, 39.56 +/- 12.12 years of age). With heat stimulation of fixed intensity (51 degrees C) on the distal forearm and distal leg, CHEPs revealed consistent waveforms with an initial negative peak (N1 latency: 398.63 +/- 28.55 and 449.03 +/- 32.21 ms for upper and lower limbs) and a later positive peak (P1 latency: 541.63 +/- 37.92 and 595.41 +/- 39.24 ms for upper and lower limbs) with N1-P1 interpeak amplitude of 42.30 +/- 12.57 microV in the upper limb and 39.67 +/- 12.03 microV in the lower limb. On analyses with models of multiple linear regression, N1-P1 amplitudes were negatively correlated with age and N1 latencies were correlated with gender, with females having shorter latencies. The verbal rating scale (VRS) for pain perception was higher in females than males, and decreased with aging. In addition, VRS paralleled changes in N1-P1 amplitude and N1 latency; the higher the VRS, the shorter the N1 latency and the higher the N1-P1 amplitude. These results provide evidence that CHEPs are influenced significantly by aging, corresponding to aging-related changes in thermal pain perception.

Contact Heat-Evoked Potential Stimulation for the Evaluation of Small Nerve Fiber Function

“…Several groups have established CHEPS as a clinically feasible approach to examine the physiology of thermonociceptive nerves. [15][16][17][18][19][20][21] CHEPS, by activating Ad fibers, can be recorded at the vertex of the skull for clinical use.…”

“…CHEPS can record a N-P waveform mediated by Ad fibers in normal subjects by applying a suprathreshold and fixedintensity thermal stimulus. 20,21 This test records the brain response to heat pain conveyed by thermonociceptive nerves and can detect dysfunctions due to small-diameter sensory nerve degeneration. Several studies have shown reduced CHEPS amplitudes and prolonged latencies in patients with skin denervation and sensory neuropathy of different causes.…”

Untersuchung des Zusammenhangs zwischen Persönlichkeitsfaktoren und der Schmerzwahrnehmung mithilfe von somatosensorisch evozierten Potentialen

“…380 -500 ms (u.a. Chen et al 2006, Greffrath et al 2007, Roberts et al 2008 (Chao et al 2007, Greffrath et al 2007, Roberts et al 2008, Warbrick et al 2009 Habituationsprozesse zurückzuführen ist (Greffrath et al 2007, Warbrick et al 2009 Harkins et al 1989, Raselli & Broderick 2007, Schmidt et al 2011, Wade et al 1992). …”

“…Verschiedene Autoren konnten einen positiven Zusammenhang zwischen den Amplituden und den subjektiven Intensitätseinschätzungen nach schmerzhaften Kontakthitzereizen nachweisen (Chao et al 2007, Moont et al 2011, Roberts et al 2008 (Chao et al 2007, Moont et al 2011, Roberts et al 2008 (Brown & Jones 2010, Brown et al 2008, Moont et al 2011). …”

Journal Club: Improved diagnosis of spinal cord disorders with contact heat evoked potentials

“…Recent studies indicate that aging interferes with the nociceptive threshold. 10 In addition, the initial negative latency correlates with sex, with shorter latencies noted in female patients.…”