Comparison of somatosensory evoked fields to airpuff and electric stimuli

doi:10.1016/0168-5597(94)90135-X

Electroencephalography and Clinical Neurophysiology/Evoked Potentials Section

Volume 92, Issue 6, November 1994, Pages 510-517

https://doi.org/10.1016/0168-5597(94)90135-X Get rights and content

Abstract

We recorded somatosensory evoked magnetic fields (SEFs) from 6 healthy subjects with a 122-channel whole-scalp SQUID gradiometer. In separate experiments, airpuff stimuli were delivered to the dorsum of the proximal phalanx of the middle finger, and electric stimuli were delivered to the median nerve at the wrist; the interstimulus interval was 3 sec and left and right hands were stimulated in subsequent sessions. Airpuffs evoked clear and reproducible responses in all subjects. First responses were recorded over the SI cortex. All subjects showed SII responses both to contra- and ipsilateral airpuffs. The posterior parietal source, identified previously to electric stimulation, was activated also by airpuffs, but only in the right hemisphere. The earliest responses from SI were smaller in amplitude and longer in latency to airpuffs than to electric stimuli; the long-latency responses arising from the other somatosensory areas did not differ significantly.

References (15)

E.P. Gardner et al.
Somatosensory evoked potentials and cortical single unit responses elicited by mechanical tactile stimuli in awake monkeys
Electroenceph. clin. Neurophysiol.
(1984)
R. Hari et al.
Somatosensory evoked cerebral magnetic fields from SI and SII in man
Electroenceph. clin. Neurophysiol.
(1984)
I. Hashimoto
Somatosensory evoked potentials elicited by air-puff stimuli generated by a new high-speed air control system
Electroenceph. clin. Neurophysiol.
(1987)
Y. Matsumiya et al.
Somatosensory evoked responses elicited by corneal and nostril air puff stimulation
Electroenceph. clin. Neurophysiol.
(1972)
T. Nakanishi et al.
Somatosensory evoked responses to tactile tap in man
Electroenceph. clin. Neurophysiol.
(1973)
H. Pratt et al.
Somatosensory potentials in humans evoked by both mechanical stimulation of the skin and electrical stimulation of the nerve
Electroenceph. clin. Neurophysiol.
(1979)
M. Schieppati et al.
Short latency cortical potentials evoked by tactile air-jet stimulation of body and face in man
Electroenceph. clin. Neurophysiol.
(1984)

There are more references available in the full text version of this article.

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Dynamic causal modeling of neural responses to an orofacial pneumotactile velocity array
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The effective connectivity of neuronal networks during orofacial pneumotactile stimulation with different velocities is still unknown. The present study aims to characterize the effectivity connectivity elicited by three different saltatory velocities (5, 25, and 65 cm/s) over the lower face using dynamic causal modeling on functional magnetic resonance imaging data of twenty neurotypical adults. Our results revealed the contralateral SI and SII as the most likely sources of the driving inputs within the sensorimotor network for the pneumotactile stimuli, suggesting parallel processing of the orofacial pneumotactile stimuli. The 25 cm/s pneumotactile stimuli modulated forward interhemispheric connection from the contralateral SII to the ipsilateral SII, suggesting a serial interhemispheric connection between the bilateral SII. Moreover, the velocity pneumotactile stimuli influenced the contralateral M1 through contralateral SI and SII, indicating that passive pneumotactile stimulation may positively impact motor function rehabilitation. Furthermore, the medium velocity 25 cm/s pneumotactile stimuli modulated both forward and backward connections between the right cerebellar lobule VI and the contralateral left SI and M1. This result suggests that the right cerebellar lobule VI plays a role in the sensorimotor network through feedforward and feedback neuronal pathways. This study is the first to map similarities and differences of effective connectivity across the three-velocity orofacial pneumotactile stimulation. Our findings shed light on the potential therapeutic use of passive orofacial pneumotactile stimuli using the Galileo system.
Somatosensory Plasticity in Hemiplegic Cerebral Palsy Following Constraint Induced Movement Therapy
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Children with hemiplegic cerebral palsy (HCP) experience upper limb somatosensory and motor deficits. Although constraint-induced movement therapy (CIMT) improves motor function, its impact on somatosensory function remains underinvestigated.
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Children with HCP attended a somatosensory enhanced CIMT camp. Clinical somatosensory (tactile registration, 2-point discrimination, stereognosis, proprioception, kinesthesia) and motor outcomes (Quality of Upper Extremity Skills [QUEST] Total/Grasp, Jebsen-Taylor Hand Function Test, grip strength, Assisting Hand Assessment), as well as latency and amplitude of magnetoencephalography somatosensory evoked fields (SEF), were assessed before and after the CIMT camp with paired sample t-tests or Wilcoxon signed-rank tests.
Twelve children with HCP (mean age: 7.5 years, standard deviation: 2.4) participated. Significant improvements in tactile registration for the affected (hemiplegic) hand (Z = 2.39, P = 0.02) were observed in addition to statistically and clinically significant improvements in QUEST total (t = 3.24, P = 0.007), QUEST grasp (t = 3.24, P = 0.007), Assisting Hand Assessment (Z = 2.25, P = 0.03), and Jebsen-Taylor Hand Function Test (t = −2.62, P = 0.03). A significant increase in the SEF peak amplitude was also found in the affected hand 100 ms after stimulus onset (t = −2.22, P = 0.04).
Improvements in somatosensory clinical function and neural processing in the affected primary somatosensory cortex in children with HCP were observed after a somatosensory enhanced CIMT program. Further investigation is warranted to continue to evaluate the effectiveness of a sensory enhanced CIMT program in larger samples and controlled study designs.
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Movie-watching is becoming a popular acquisition method to increase compliance and enable neuroimaging data collection in challenging populations such as children, with potential to facilitate studying the somatosensory system. However, relatively little is known about the possible crossmodal (audiovisual) influence of movies on cortical somatosensory processing. In this study, we examined the impact of dynamic audiovisual movies on concurrent cortical somatosensory processing using electroencephalography (EEG). Forty healthy young adults (18–25 years) received passive tactile fingertip stimulation while watching an “entertaining” movie and a novel “low-demand” movie called ‘Inscapes’ compared to eyes-open rest. Watching a movie did not modulate properties of early or late somatosensory-evoked potentials (SEPs). Similarly, no crossmodal influence on somatosensory adaptation, denoted by a reduction in SEP amplitude with repetitive tactile stimulation, was found. The prominent oscillatory responses in the alpha and beta frequency bands following tactile stimulation differed as a function of viewing condition, with stronger alpha/beta event-related desynchronization (ERD) during movie-watching compared to rest. These findings highlight that movie-watching is a valid acquisition method during which SEPs can be measured in basic research and clinical studies, but that the attentional demands of movies need to be taken into account when performing oscillatory analyses.
Altered neocortical tactile but preserved auditory early change detection responses in Friedreich ataxia
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Citation Excerpt :
The better sensitivity of MEG may be due to various and non-exclusive factors: higher sensors number (306 sensors for MEG vs. eight scalp electrodes for SSEP), better signal to noise ratio for focal neocortical sources and heightened sensitivity to tangential neocortical sources such as area 3b of SI cortex (Goldenholz et al., 2009) that are the primary cortical area for tactile processing (Keysers et al., 2010). Furthermore, in this study, we used pneumatic tactile stimuli that may recruit smaller caliber, less affected nerve fibers than electrical stimuli (Forss et al., 1994). Overall, our results indicate that MEG is a sensitive tool to study cortical sensory processing in diseases affecting the afferent sensory pathways such as FRDA.
To study using magnetoencephalography (MEG) the spatio-temporal dynamics of neocortical responses involved in sensory processing and early change detection in Friedreich ataxia (FRDA).
Tactile (TERs) and auditory (AERs) evoked responses, and early neocortical change detection responses indexed by the mismatch negativity (MMN) were recorded using tactile and auditory oddballs in sixteen FRDA patients and matched healthy subjects. Correlations between the maximal amplitude of each response, genotype and clinical parameters were investigated.
Evoked responses were detectable in all FRDA patients but one. In patients, TERs were delayed and reduced in amplitude, while AERs were only delayed. Only tactile MMN responses at the contralateral secondary somatosensory cortex were altered in FRDA patients. Maximal amplitudes of TERs, AERs and tactile MMN correlated with genotype, but did not correlate with clinical parameters.
In FRDA, the amplitude of tactile MMN responses at SII cortex are reduced and correlate with the genotype, while auditory MMN responses are not altered.
Somatosensory pathways and tactile early change detection are selectively impaired in FRDA.
Detecting differences with magnetoencephalography of somatosensory processing after tactile and electrical stimuli
2019, Journal of Neuroscience Methods
Citation Excerpt :
Hadoush et al. (2010) reported similar results as found here with differences in the activated brain areas between mechanical tactile and electrical stimulation and they hypothesized that the ipsilateral SI activation could be recorded more consistently after mechanical tactile stimulation in contrast with electrical stimulation due to the more selective tactile sensory input. Whereas tactile stimuli activate more uniform fiber types (Pratt et al., 1979), electrical stimulation activates a large number of fiber types with different conduction velocities (Forss et al., 1994; Gandevia et al., 1982; Kimura, 2001). Our results indicate that tactile stimulation is a feasible method for investigating the somatosensory change detection system.
Deviant stimuli within a standard, frequent stimulus train induce a cortical somatosensory mismatch response (SMMR). The SMMR reflects the brain’s automatic mechanism for the detection of change in a somatosensory domain. It is usually elicited by electrical stimulation, which activates nerve fibers and receptors in superficial and deep skin layers, whereas tactile stimulation is closer to natural stimulation and activates uniform fiber types. We recorded SMMRs after electrical and tactile stimuli.
306-channel magnetoencephalography recordings were made with 16 healthy adults under two conditions: electrical (eSMMR) and tactile (tSMMR) stimulations. The SMMR protocol consisted of 1000 stimuli with 10% deviants to fingers.
Sensor-level analysis revealed stronger activation after deviant stimulation in bilateral channel locations approximately corresponding to parietal cortical areas within both stimulation conditions. Between conditions, deviant tSMMR showed stronger activation in the ipsilateral channels. Based on sensor-level results, two components, M50 and SMMR (40–58 and 110–185 ms), were compared at the source-level. Deviant stimulation elicited stronger contralateral SI activation during M50 component in both conditions. SMMR was observed with both conditions, activating contralateral SII after deviant stimulation. However, only tSMMR showed long latency activation in bilateral SI cortices. This suggests that there is an integration of both body sides during the automatic stages of tactile processing in SI cortices.
This study indicates that tactile stimulation (tSMMR) is a feasible method for investigating the brain’s mechanism for detecting somatosensory changes; this may extend the clinical utility of tSMMR for assessing disorders involving altered somatosensory processing.

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Main articleComparison of somatosensory evoked fields to airpuff and electric stimuli

Abstract

Electroenceph. clin. Neurophysiol.

Electroenceph. clin. Neurophysiol.

Electroenceph. clin. Neurophysiol.

Electroenceph. clin. Neurophysiol.

Electroenceph. clin. Neurophysiol.

Electroenceph. clin. Neurophysiol.

Electroenceph. clin. Neurophysiol.

Main article
Comparison of somatosensory evoked fields to airpuff and electric stimuli