scholarly journals Transcutaneous auricular VNS applied to experimental pain: A paired behavioral and EEG study using thermonociceptive CO2 laser

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254480
Author(s):  
Manon Dumoulin ◽  
Giulia Liberati ◽  
André Mouraux ◽  
Susana Ferrao Santos ◽  
Riëm El Tahry

Background Transcutaneous auricular Vagal Nerve Stimulation (taVNS) is a non-invasive neurostimulation technique with potential analgesic effects. Several studies based on subjective behavioral responses suggest that taVNS modulates nociception differently with either pro-nociceptive or anti-nociceptive effects. Objective This study aimed to characterize how taVNS alters pain perception, by investigating its effects on event-related potentials (ERPs) elicited by different types of spinothalamic and lemniscal somatosensory stimuli, combined with quantitative sensory testing (detection threshold and intensity ratings). Methods We performed 3 experiments designed to study the time-dependent effects of taVNS and compare with standard cervical VNS (cVNS). In Experiment 1, we assessed the effects of taVNS after 3 hours of stimulation. In Experiment 2, we focused on the immediate effects of the duty cycle (OFF vs. ON phases). Experiments 1 and 2 included 22 and 15 healthy participants respectively. Both experiments consisted of a 2-day cross-over protocol, in which subjects received taVNS and sham stimulation sequentially. In addition, subjects received a set of nociceptive (thermonociceptive CO2 laser, mechanical pinprick) and non-nociceptive (vibrotactile, cool) stimuli, for which we recorded detection thresholds, intensity of perception and ERPs. Finally, in Experiment 3, we tested 13 epileptic patients with an implanted cVNS by comparing OFF vs. ON cycles, using a similar experimental procedure. Results Neither taVNS nor cVNS appeared to modulate the cerebral and behavioral aspects of somatosensory perception. Conclusion The potential effect of taVNS on nociception requires a cautious interpretation, as we found no objective change in behavioral and cerebral responses to spinothalamic and lemniscal somatosensory stimulations.

2020 ◽  
Vol 16 (2) ◽  
pp. 138-152
Author(s):  
Bingren Zhang ◽  
Chu Wang ◽  
Chanchan Shen ◽  
Wei Wang

Background: Responses to external emotional-stimuli or their transitions might help to elucidate the scientific background and assist the clinical management of psychiatric problems, but pure emotional-materials and their utilization at different levels of neurophysiological processing are few. Objective: We aimed to describe the responses at central and peripheral levels in healthy volunteers and psychiatric patients when facing external emotions and their transitions. Methods: Using pictures and sounds with pure emotions of Disgust, Erotica, Fear, Happiness, Neutral, and Sadness or their transitions as stimuli, we have developed a series of non-invasive techniques, i.e., the event-related potentials, functional magnetic resonance imaging, excitatory and inhibitory brainstem reflexes, and polygraph, to assess different levels of neurophysiological responses in different populations. Results: Sample outcomes on various conditions were specific and distinguishable at cortical to peripheral levels in bipolar I and II disorder patients compared to healthy volunteers. Conclusions: Methodologically, designs with these pure emotions and their transitions are applicable, and results per se are specifically interpretable in patients with emotion-related problems.


2011 ◽  
Vol 02 (02) ◽  
pp. 130-136 ◽  
Author(s):  
Keshab Raj Paudel ◽  
SK Bhattacharya ◽  
GP Rauniar ◽  
BP Das

ABSTRACT Introduction: Newer anticonvulsants have a neuromodulatory effect on pain perception mechanisms in a hyperexcitable and damaged nervous system. Aim: This study was designed to study the analgesic effects of gabapentin alone and in combination with lamotrigine and topiramate in experimental pain models. Materials and Methods: Adult albino mice (n = 490) weighing 20–30 g and rats (n = 130) weighing 100–200 g were injected intraperitoneally with gabapentin, lamotrigine, and topiramate alone and in different dose combinations. The hot-plate method, tail-flick method, capsaicin-induced mechanical hyperalgesia, and formalin assay were used to assess the antinociceptive effects. Results: Of the three antiepileptic drugs, when given separately, gabapentin was more efficacious than either topiramate or lamotrigine in all the pain models. Combination of 25 mg/kg gabapentin with 25 mg/kg topiramate was more efficacious (P <.05) than 50 mg/kg gabapentin alone in the capsaicin-induced mechanical hyperalgesia test. Similarly, 50 mg/kg gabapentin with 50 mg/kg topiramate or 5 mg/kg lamotrigine was more efficacious (P <.05) than 50 or 100 mg/kg gabapentin alone in late-phase formalin-induced behaviors. Conclusions: Combination of gabapentin with either lamotrigine or topiramate produced better results than gabapentin alone in capsaicin-induced mechanical hyperalgesia test and in late-phase formalin-induced behaviors.


2011 ◽  
Vol 106 (6) ◽  
pp. 3216-3229 ◽  
Author(s):  
L. Hu ◽  
M. Liang ◽  
A. Mouraux ◽  
R. G. Wise ◽  
Y. Hu ◽  
...  

Across-trial averaging is a widely used approach to enhance the signal-to-noise ratio (SNR) of event-related potentials (ERPs). However, across-trial variability of ERP latency and amplitude may contain physiologically relevant information that is lost by across-trial averaging. Hence, we aimed to develop a novel method that uses 1) wavelet filtering (WF) to enhance the SNR of ERPs and 2) a multiple linear regression with a dispersion term (MLRd) that takes into account shape distortions to estimate the single-trial latency and amplitude of ERP peaks. Using simulated ERP data sets containing different levels of noise, we provide evidence that, compared with other approaches, the proposed WF+MLRd method yields the most accurate estimate of single-trial ERP features. When applied to a real laser-evoked potential data set, the WF+MLRd approach provides reliable estimation of single-trial latency, amplitude, and morphology of ERPs and thereby allows performing meaningful correlations at single-trial level. We obtained three main findings. First, WF significantly enhances the SNR of single-trial ERPs. Second, MLRd effectively captures and measures the variability in the morphology of single-trial ERPs, thus providing an accurate and unbiased estimate of their peak latency and amplitude. Third, intensity of pain perception significantly correlates with the single-trial estimates of N2 and P2 amplitude. These results indicate that WF+MLRd can be used to explore the dynamics between different ERP features, behavioral variables, and other neuroimaging measures of brain activity, thus providing new insights into the functional significance of the different brain processes underlying the brain responses to sensory stimuli.


2001 ◽  
Vol 6 (3) ◽  
pp. 126-132 ◽  
Author(s):  
Stephen J Gibson ◽  
Xenophon Voukelatos ◽  
David Ames ◽  
Leon Flicker ◽  
Robert D Helme

BACKGROUND: Pain perception is known to depend on integrated cognitive processing. Alzheimer's disease affects 5% to 10% of older adults, but the impact of this disease on pain sensitivity and report has yet to be fully investigated.AIM OF INVESTIGATION: The present study examined pain threshold, the reliability of pain report and the central nervous system processing of noxious input, as indexed by cerebral event-related potentials (CERP).METHODS: Carbon dioxide laser detection and heat pain thresholds were determined on the hand dorsum of 15 healthy older adults (Mini-Mental State Examination [MMSE] score 29.9±0.3) and 15 persons with cognitive impairment (MMSE score 12.7±6.1). Using an array of 15 silver/silver chloride scalp electrodes, the CERP and subjective rating of stimulus intensity were recorded after fixed intensity, 25 W laser stimuli.RESULTS: Compared with age-matched controls, the detection threshold for just noticeable sensation was significantly increased in elderly adults suffering from Alzheimer's disease. There was no difference in pain threshold intensity between persons with cognitive impairment and controls, although the former group was less reliable in reporting detection and pain threshold sensations. The subjective rating of a 25 W stimulus was virtually identical in both groups, and the amplitude of the major CERP component (P400) was similar; however, cognitively impaired adults exhibited a significant increase in the latency of the P400 response.CONCLUSION: The present findings indicate that pain perception in response to an acute heat pain stimulus is not diminished in older persons with cognitive impairment. Patients with Alzheimer's disease may be slightly less reliable in threshold pain report, although the subjective rating of evoked pain and the level of poststimulus cortical activation following noxious stimulation were found to be similar to those of controls. A longer latency of the CERP may suggest slower cortical processing of nociceptive input by persons with Alzheimer's disease.


2020 ◽  
Vol 7 (12) ◽  
pp. 200851
Author(s):  
L. Magyari ◽  
Zs. Huszár ◽  
A. Turzó ◽  
A. Andics

While dogs have remarkable abilities for social cognition and communication, the number of words they learn to recognize typically remains very low. The reason for this limited capacity is still unclear. We hypothesized that despite their human-like auditory abilities for analysing speech sounds, their word processing capacities might be less ready to access phonetic details. To test this, we developed procedures for non-invasive measurement of event-related potentials (ERPs) for language stimuli in awake dogs ( n = 17). Dogs listened to familiar instruction words and phonetically similar and dissimilar nonsense words. We compared two different artefact cleaning procedures on the same data; they led to similar results. An early (200–300 ms; only after one of the cleaning procedures) and a late (650–800 ms; after both cleaning procedures) difference was present in the ERPs for known versus phonetically dissimilar nonsense words. There were no differences between the ERPs for known versus phonetically similar nonsense words. ERPs of dogs who heard the instructions more often also showed larger differences between instructions and dissimilar nonsense words. The study revealed not only dogs' sensitivity to known words, but also their limited capacity to access phonetic details. Future work should confirm the reported ERP correlates of word processing abilities in dogs.


Cephalalgia ◽  
1995 ◽  
Vol 15 (4) ◽  
pp. 301-309 ◽  
Author(s):  
A Maertens de Noordhout ◽  
W Wang ◽  
J Schoenen

Clinical neurophysiology allows non-invasive assessment of neurotransmitter function in various regions of the central and peripheral nervous system. In this review, we describe examples of functional evaluation of neurotransmission at the neuromuscular junction, in some spinal interneurons and intracortical circuits as well as evaluation of pharmacological modulation of some electrophysiological tests. These investigations are carried out to help our understanding of the pathophysiology of brain diseases. Finally, we discuss possible relationships between electrophysiological tests (evoked/event-related potentials and exteroceptive suppression of temporalis muscle activity) and neurotransmitter function in headache.


2010 ◽  
Vol 103 (4) ◽  
pp. 2107-2113 ◽  
Author(s):  
Emanuel N. van den Broeke ◽  
Clementina M. van Rijn ◽  
José A. Biurrun Manresa ◽  
Ole K. Andersen ◽  
Lars Arendt-Nielsen ◽  
...  

Long-term potentiation (LTP) is a cellular model of synaptic plasticity and reflects an increase of synaptic strength. LTP is also present in the nociceptive system and is believed to be one of the key mechanisms involved in the manifestations of chronic pain. LTP manifested as an increased response in pain perception can be induced in humans using high-frequency electrical stimulation (HFS). The aim of this study was to induce spinal heterosynaptic LTP using HFS and investigate its heterotopic effects on event-related potentials (ERPs) to repeated nonpainful cutaneous stimuli as a possible electrophysiological cortical correlate of sensitization. Twenty-two healthy subjects were randomly assigned to one of the two experimental conditions: HFS and control stimulation. Before and after the stimulation, both conditions received heterotopic mechanical (pinprick) and paired nonpainful electrical test stimuli to quantify and confirm the effects of HFS on the behavioral level. ERPs to paired nonpainful electrical stimulation were measured simultaneously. Conditioning HFS resulted in significant heterotopic effects after 30 min, including increased perceived intensity in response to (pinprick) mechanical and paired nonpainful electrical stimulation compared with control. The paired nonpainful electrical stimuli were accompanied by significantly enhanced responses regarding the ERP N1-P2 peak-to-peak and P300 amplitude compared with control. These findings suggest that HFS is capable of producing heterosynaptic spinal LTP that can be measured not only behaviorally but also using ERPs.


2020 ◽  
Vol 10 (6) ◽  
pp. 404 ◽  
Author(s):  
Claire V. Warren ◽  
María J. Maraver ◽  
Alberto de Luca ◽  
Bruno Kopp

Transcutaneous auricular Vagal Nerve Stimulation (taVNS) is a non-invasive brain stimulation technique associated with possible modulation of norepinephrinergic (NE) activity. NE is suspected to contribute to generation of the P3 event-related potential. Recent evidence has produced equivocal evidence whether taVNS influences the P3 in healthy individuals during oddball tasks. We examined the effect of taVNS on P3 amplitudes using a novel visual Bayesian oddball task, which presented 200 sequences of three stimuli. The three consecutive stimuli in each sequence are labelled Draw 1, Draw 2 and Draw 3. In total, 47 Subjects completed this visual Bayesian oddball task under randomised sham and active taVNS stimulation in parallel with an electroencephalographic (EEG) recording. We conducted exploratory analyses of the effect of taVNS on P3 amplitudes separately for Draws. We found typical oddball effects on P3 amplitudes at Draws 1 and 2, but not Draw 3. At Draw 2, the oddball effect was enhanced during active compared to sham taVNS stimulation. These data provide evidence that taVNS influences parietal P3 amplitudes under specific circumstances. Only P3 amplitudes at Draw 2 were affected, which may relate to closure of Bayesian inference after Draw 2. Our findings seemingly support previously reported links between taVNS and the NE system.


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