Neurophysiological evaluation of healthy human anorectal sensation

2006 ◽  
Vol 291 (5) ◽  
pp. G950-G958 ◽  
Author(s):  
M. L. Harris ◽  
A. R. Hobson ◽  
S. Hamdy ◽  
D. G. Thompson ◽  
L. M. Akkermans ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Intraclass Correlation ◽  
Functional Gastrointestinal Disorders ◽  
Sensory Threshold ◽  
Rectal Sensation ◽  
Healthy Human ◽  
Afferent Pathways ◽  
Central Processing ◽  
Balloon Distension ◽  
Sensory Evoked

Patients with functional gastrointestinal disorders often demonstrate abnormal visceral sensation. Currently, rectal sensation is assessed by manual balloon distension or barostat. However, neither test is adaptable for use in the neurophysiological characterization of visceral afferent pathways by sensory evoked potentials. The aim of this study was to assess the reproducibility and quality of sensation evoked by electrical stimulation (ES) and rapid balloon distension (RBD) in the anorectum and to apply the optimum stimulus to examine the visceral afferent pathway with rectal evoked potentials. Healthy subjects ( n = 8, median age 33 yr) were studied on three separate occasions. Variability, tolerance, and stimulus characteristics were assessed with each technique. Overall ES consistently invoked pain and was chosen for measuring rectal evoked potential whereas RBD in all cases induced the strong urge to defecate. Rectal intraclass correlation coefficient (ICC) for ES and RBD (0.82 and 0.72, respectively) demonstrated good reproducibility at pain/maximum tolerated volume but not at sensory threshold. Only sphincter ICC for ES at pain showed acceptable between-study reproducibility (ICC 0.79). Within studies ICC was good (>0.6) for anorectal ES and RBD at both levels of sensation. All subjects reported significantly more unpleasantness during RBD than ES ( P < 0.01). This study demonstrates that ES and RBD are similarly reproducible. However, the sensations experienced with each technique differed markedly, probably reflecting differences in peripheral and/or central processing of the sensory input. This is of relevance in interpreting findings of neuroimaging studies of anorectal sensation and may provide insight into the physiological characteristics of visceral afferent pathways in health and disease.

Pinprick Evoked Potentials—Reliable Acquisition in Healthy Human Volunteers

Pain Medicine ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 736-746 ◽  
Author(s):  
Jan Rosner ◽  
Paulina Simonne Scheuren ◽  
Stephanie Anja Stalder ◽  
Armin Curt ◽  
Michèle Hubli
Keyword(s):  
Evoked Potentials ◽  
Intraclass Correlation ◽  
Age Groups ◽  
Sensory Nerve ◽  
Correlation Coefficients ◽  
Nerve Fibers ◽  
Healthy Human ◽  
Stimulation Intensity ◽  
Sensory Deficits ◽  
Nociceptive Pathways

Abstract Objective Pinprick evoked potentials (PEPs) represent a novel tool to assess the functional integrity of mechano-nociceptive pathways with a potential toward objectifying sensory deficits and gain seen in neurological disorders. The aim of the present study was to evaluate the feasibility and reliability of PEPs with respect to age, stimulation site, and skin type. Methods Electroencephalographic responses evoked by two pinprick stimulation intensities (128 mN and 256 mN) applied at three sites (hand dorsum, palmar digit II, and foot dorsum) were recorded in 30 healthy individuals. Test–retest reliability was performed for the vertex negative–positive complex amplitudes, N-latencies, and pain ratings evoked by the 256mN stimulation intensity. Results Feasibility of PEP acquisition was demonstrated across age groups, with higher proportions of evoked potentials (&gt;85%) for the 256mN stimulation intensity. Reliability analyses, that is, Bland-Altman and intraclass correlation coefficients, revealed poor to excellent reliability upon retest depending on the stimulation sites. Conclusions This study highlights the reliability of PEP acquisition from cervical and lumbar segments across clinically representative age groups. Future methodological improvements might further strengthen PEP reliability in order to complement clinical neurophysiology of sensory nerve fibers by a more specific assessment of mechano-nociceptive pathways. Beyond looking at sensory deficits, PEPs may also become applicable to revealing signs of central sensitization, complementing the clinical assessment of mechanical hyperalgesia.

Cortical processing of human gut sensation: an evoked potential study

2002 ◽  
Vol 283 (2) ◽  
pp. G335-G339 ◽  
Author(s):  
David I. Hobday ◽  
Anthony R. Hobson ◽  
Sanchoy Sarkar ◽  
Paul L. Furlong ◽  
David G. Thompson ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Evoked Potential ◽  
Physiological Role ◽  
Cortical Processing ◽  
Human Gut ◽  
Rectal Sensation ◽  
Afferent Pathways ◽  
Central Processing ◽  
Age Range ◽  
Afferent Innervation

The rectum has a unique physiological role as a sensory organ and differs in its afferent innervation from other gut organs that do not normally mediate conscious sensation. We compared the central processing of human esophageal, duodenal, and rectal sensation using cortical evoked potentials (CEP) in 10 healthy volunteers (age range 21–34 yr). Esophageal and duodenal CEP had similar morphology in all subjects, whereas rectal CEP had two different but reproducible morphologies. The rectal CEP latency to the first component P1 (69 ms) was shorter than both duodenal (123 ms; P = 0.008) and esophageal CEP latencies (106 ms; P = 0.004). The duodenal CEP amplitude of the P1-N1 component (5.0 μV) was smaller than that of the corresponding esophageal component (5.7 μV; P = 0.04) but similar to that of the corresponding rectal component (6.5 μV; P = 0.25). This suggests that rectal sensation is either mediated by faster-conducting afferent pathways or that there is a difference in the orientation or volume of cortical neurons representing the different gut organs. In conclusion, the physiological and anatomic differences between gut organs are reflected in differences in the characteristics of their afferent pathways and cortical processing.

scholarly journals Delta and gamma oscillations in operculo-insular cortex underlie innocuous cold thermosensation

2017 ◽  
Vol 117 (5) ◽  
pp. 1959-1968 ◽  
Author(s):  
Francesca Fardo ◽  
Mikkel C. Vinding ◽  
Micah Allen ◽  
Troels Staehelin Jensen ◽  
Nanna Brix Finnerup
Keyword(s):  
Evoked Potentials ◽  
Time Course ◽  
Pain Perception ◽  
Functional Integration ◽  
Gamma Oscillations ◽  
Oscillatory Activity ◽  
Neural Pathways ◽  
Healthy Human ◽  
Central Processing ◽  
Evoked Fields

Cold-sensitive and nociceptive neural pathways interact to shape the quality and intensity of thermal and pain perception. Yet the central processing of cold thermosensation in the human brain has not been extensively studied. Here, we used magnetoencephalography and EEG in healthy volunteers to investigate the time course (evoked fields and potentials) and oscillatory activity associated with the perception of cold temperature changes. Nonnoxious cold stimuli consisting of Δ3°C and Δ5°C decrements from an adapting temperature of 35°C were delivered on the dorsum of the left hand via a contact thermode. Cold-evoked fields peaked at around 240 and 500 ms, at peak latencies similar to the N1 and P2 cold-evoked potentials. Importantly, cold-related changes in oscillatory power indicated that innocuous thermosensation is mediated by oscillatory activity in the range of delta (1–4 Hz) and gamma (55–90 Hz) rhythms, originating in operculo-insular cortical regions. We suggest that delta rhythms coordinate functional integration between operculo-insular and frontoparietal regions, while gamma rhythms reflect local sensory processing in operculo-insular areas. NEW & NOTEWORTHY Using magnetoencephalography, we identified spatiotemporal features of central cold processing, with respect to the time course, oscillatory profile, and neural generators of cold-evoked responses in healthy human volunteers. Cold thermosensation was associated with low- and high-frequency oscillatory rhythms, both originating in operculo-insular regions. These results support further investigations of central cold processing using magnetoencephalography or EEG and the clinical utility of cold-evoked potentials for neurophysiological assessment of cold-related small-fiber function and damage.

scholarly journals Scalp Topography of Lower Urinary Tract Sensory Evoked Potentials

2020 ◽  
Vol 33 (6) ◽  
pp. 693-709
Author(s):  
Stéphanie van der Lely ◽  
Thomas M. Kessler ◽  
Ulrich Mehnert ◽  
Martina D. Liechti
Keyword(s):  
Electrical Stimulation ◽  
Urinary Tract ◽  
Evoked Potentials ◽  
Lower Urinary Tract ◽  
Afferent Pathways ◽  
Custom Made ◽  
Topographical Distribution ◽  
Sensory Evoked Potentials ◽  
Sensory Evoked ◽  
Lower Urinary

Abstract Impaired lower urinary tract (LUT) afferents often cause LUT symptoms. Assessment of LUT afferent pathways is possible using bipolar cortical sensory evoked potential (SEP) recordings with the active electrode at the vertex during electrical stimulation in the LUT. This study aimed to investigate the topographical distribution and microstates of lower urinary tract sensory evoked potentials (LUTSEPs) using different stimulation frequencies. Ninety healthy subjects (18–36 years old, 40 women) were randomly assigned to one of five stimulation locations [bladder dome; trigone; proximal, membranous (men only) or distal urethra]. Cycles of 0.5 Hz/1.1 Hz/1.6 Hz electrical stimulation were applied using a custom-made catheter. Cortical activity was recorded from 64 surface electrodes. Marker setting was performed manually on an individual subject-level for the P1, N1, and P2 components of vertex recordings. N1 and P2 topographies presented with central negativities and positivities around the vertex. Regarding topographical distribution, Randomization Graphical User interface (RAGU) analyses revealed consistent frequency effects and microstates for N1/P2. Higher stimulation frequencies resulted in decreasing map strength for P1, N1, and P2. LUTSEP topographies suggest central generators in the somatosensory cortex, which are not detectable in a bipolar set-up. The observed frequency effect indicates fiber refractoriness at higher frequencies. The multichannel approach allows more comprehensive assessment of LUTSEPs and might therefore be sensitive to pathological changes. Examinations in patients with LUT symptoms are needed to further investigate this biomarker.

Latencies of vagus sensory evoked potentials are prolonged in Parkinson's disease

2009 ◽  
Vol 36 (S 02) ◽  
Author(s):  
T Polak ◽  
D Weise ◽  
F Metzger ◽  
A Schramm ◽  
AJ Fallgatter ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Evoked Potentials ◽  
Sensory Evoked Potentials ◽  
Sensory Evoked

scholarly journals Clinical Validation of the Champagne Algorithm for Evoked Response Source Localization in Magnetoencephalography

2021 ◽  
Author(s):  
Abhishek S. Bhutada ◽  
Chang Cai ◽  
Danielle Mizuiri ◽  
Anne Findlay ◽  
Jessie Chen ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Source Localization ◽  
Clinical Population ◽  
Evoked Responses ◽  
Localization Algorithm ◽  
Equivalent Current Dipole ◽  
Current Dipole ◽  
Tumor Patients ◽  
Equivalent Current ◽  
Sensory Evoked

AbstractMagnetoencephalography (MEG) is a robust method for non-invasive functional brain mapping of sensory cortices due to its exceptional spatial and temporal resolution. The clinical standard for MEG source localization of functional landmarks from sensory evoked responses is the equivalent current dipole (ECD) localization algorithm, known to be sensitive to initialization, noise, and manual choice of the number of dipoles. Recently many automated and robust algorithms have been developed, including the Champagne algorithm, an empirical Bayesian algorithm, with powerful abilities for MEG source reconstruction and time course estimation (Wipf et al. 2010; Owen et al. 2012). Here, we evaluate automated Champagne performance in a clinical population of tumor patients where there was minimal failure in localizing sensory evoked responses using the clinical standard, ECD localization algorithm. MEG data of auditory evoked potentials and somatosensory evoked potentials from 21 brain tumor patients were analyzed using Champagne, and these results were compared with equivalent current dipole (ECD) fit. Across both somatosensory and auditory evoked field localization, we found there was a strong agreement between Champagne and ECD localizations in all cases. Given resolution of 8mm voxel size, peak source localizations from Champagne were below 10mm of ECD peak source localization. The Champagne algorithm provides a robust and automated alternative to manual ECD fits for clinical localization of sensory evoked potentials and can contribute to improved clinical MEG data processing workflows.

Evoked potentials and central processing of visual information

1971 ◽  
Vol 11 ◽  
pp. 457-477 ◽  
Author(s):  
E. García Austt ◽  
W. Bun˜o ◽  
A. Vanzulli
Keyword(s):  
Evoked Potentials ◽  
Visual Information ◽  
Central Processing ◽  
Processing Of Visual Information

Comparison of sensory evoked potentials during neurosurgery under remimazolam anesthesia with those under propofol anesthesia

2021 ◽  
Author(s):  
Ryusuke TANAKA ◽  
Atsushi SATO ◽  
Kenji SHINOHARA ◽  
Tohru SHIRATORI ◽  
Chiaki KIUCHI ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Sensory Evoked Potentials ◽  
Sensory Evoked
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