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Measurement of pharyngeal sensory cortical processing: technique and physiologic implications.

Teismann IK, Steinstraeter O, Warnecke T, Ringelstein EB, Pantev C, Dziewas R - BMC Neurosci (2009)

Bottom Line: The results are in keeping with previous findings showing bihemispheric involvement in the complex task of sensory pharyngeal processing.They might also explain changes in deglutition after hemispheric strokes.The ipsilaterally lateralized processing is surprising and needs further investigation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute for Biomagnetism and Biosignalanalysis, University of Muenster, Malmedyweg 15, 48149 Muenster, Germany. i.teismann@uni-muenster.de

ABSTRACT

Background: Dysphagia is a major complication of different diseases affecting both the central and peripheral nervous system. Pharyngeal sensory impairment is one of the main features of neurogenic dysphagia. Therefore an objective technique to examine the cortical processing of pharyngeal sensory input would be a helpful diagnostic tool in this context. We developed a simple paradigm to perform pneumatic stimulation to both sides of the pharyngeal wall. Whole-head MEG was employed to study changes in cortical activation during this pharyngeal stimulation in nine healthy subjects. Data were analyzed by means of synthetic aperture magnetometry (SAM) and the group analysis of individual SAM data was performed using a permutation test.

Results: Our results revealed bilateral activation of the caudolateral primary somatosensory cortex following sensory pharyngeal stimulation with a slight lateralization to the side of stimulation.

Conclusion: The method introduced here is simple and easy to perform and might be applicable in the clinical setting. The results are in keeping with previous findings showing bihemispheric involvement in the complex task of sensory pharyngeal processing. They might also explain changes in deglutition after hemispheric strokes. The ipsilaterally lateralized processing is surprising and needs further investigation.

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Related in: MedlinePlus

Time-frequency wavelet plots. Wavelet analysis of the virtual channels representing the individual maximum ERD (left: maximum ERD over the left hemisphere; right: maximum ERD over the right hemisphere). Colors represent the percental change of frequency power relative to baseline (100%) as indicated in the color bar. Changes relative to the baseline interval (-0.5 – 0 sec., whereas 0 is SO) are calculated separately for each frequency. The time points used to define the time intervals of interest are marked (SO = stimulus onset). A distinct decrease of frequency power in the beta frequency range after stimulus onset and a re-increase after pneumatic stimulation stopped is found. The effect is comparable in both hemispheres.
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Figure 1: Time-frequency wavelet plots. Wavelet analysis of the virtual channels representing the individual maximum ERD (left: maximum ERD over the left hemisphere; right: maximum ERD over the right hemisphere). Colors represent the percental change of frequency power relative to baseline (100%) as indicated in the color bar. Changes relative to the baseline interval (-0.5 – 0 sec., whereas 0 is SO) are calculated separately for each frequency. The time points used to define the time intervals of interest are marked (SO = stimulus onset). A distinct decrease of frequency power in the beta frequency range after stimulus onset and a re-increase after pneumatic stimulation stopped is found. The effect is comparable in both hemispheres.

Mentions: Wavelet analysis of virtual channel recordings over the individual maximum event related desynchronization (ERD) in each hemisphere revealed a reduction of power in the beta frequency range directly after stimulus onset. A re-increase of power was found after ending of sensory stimulation. ANOVA and post-hoc t-tests revealed a decrease of beta power from the 'control time window' to the 'active time window' after stimulation to both sides of the pharyngeal wall and in both hemispheres [see figure 1].


Measurement of pharyngeal sensory cortical processing: technique and physiologic implications.

Teismann IK, Steinstraeter O, Warnecke T, Ringelstein EB, Pantev C, Dziewas R - BMC Neurosci (2009)

Time-frequency wavelet plots. Wavelet analysis of the virtual channels representing the individual maximum ERD (left: maximum ERD over the left hemisphere; right: maximum ERD over the right hemisphere). Colors represent the percental change of frequency power relative to baseline (100%) as indicated in the color bar. Changes relative to the baseline interval (-0.5 – 0 sec., whereas 0 is SO) are calculated separately for each frequency. The time points used to define the time intervals of interest are marked (SO = stimulus onset). A distinct decrease of frequency power in the beta frequency range after stimulus onset and a re-increase after pneumatic stimulation stopped is found. The effect is comparable in both hemispheres.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2719647&req=5

Figure 1: Time-frequency wavelet plots. Wavelet analysis of the virtual channels representing the individual maximum ERD (left: maximum ERD over the left hemisphere; right: maximum ERD over the right hemisphere). Colors represent the percental change of frequency power relative to baseline (100%) as indicated in the color bar. Changes relative to the baseline interval (-0.5 – 0 sec., whereas 0 is SO) are calculated separately for each frequency. The time points used to define the time intervals of interest are marked (SO = stimulus onset). A distinct decrease of frequency power in the beta frequency range after stimulus onset and a re-increase after pneumatic stimulation stopped is found. The effect is comparable in both hemispheres.
Mentions: Wavelet analysis of virtual channel recordings over the individual maximum event related desynchronization (ERD) in each hemisphere revealed a reduction of power in the beta frequency range directly after stimulus onset. A re-increase of power was found after ending of sensory stimulation. ANOVA and post-hoc t-tests revealed a decrease of beta power from the 'control time window' to the 'active time window' after stimulation to both sides of the pharyngeal wall and in both hemispheres [see figure 1].

Bottom Line: The results are in keeping with previous findings showing bihemispheric involvement in the complex task of sensory pharyngeal processing.They might also explain changes in deglutition after hemispheric strokes.The ipsilaterally lateralized processing is surprising and needs further investigation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute for Biomagnetism and Biosignalanalysis, University of Muenster, Malmedyweg 15, 48149 Muenster, Germany. i.teismann@uni-muenster.de

ABSTRACT

Background: Dysphagia is a major complication of different diseases affecting both the central and peripheral nervous system. Pharyngeal sensory impairment is one of the main features of neurogenic dysphagia. Therefore an objective technique to examine the cortical processing of pharyngeal sensory input would be a helpful diagnostic tool in this context. We developed a simple paradigm to perform pneumatic stimulation to both sides of the pharyngeal wall. Whole-head MEG was employed to study changes in cortical activation during this pharyngeal stimulation in nine healthy subjects. Data were analyzed by means of synthetic aperture magnetometry (SAM) and the group analysis of individual SAM data was performed using a permutation test.

Results: Our results revealed bilateral activation of the caudolateral primary somatosensory cortex following sensory pharyngeal stimulation with a slight lateralization to the side of stimulation.

Conclusion: The method introduced here is simple and easy to perform and might be applicable in the clinical setting. The results are in keeping with previous findings showing bihemispheric involvement in the complex task of sensory pharyngeal processing. They might also explain changes in deglutition after hemispheric strokes. The ipsilaterally lateralized processing is surprising and needs further investigation.

Show MeSH
Related in: MedlinePlus