Measurement of pharyngeal sensory cortical processing: technique and physiologic implications

<p>Abstract</p> <p>Background</p> <p>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.</p> <p>Results</p> <p>Our results revealed bilateral activation of the caudolateral primary somatosensory cortex following sensory pharyngeal stimulation with a slight lateralization to the side of stimulation.</p> <p>Conclusion</p> <p>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.</p

The Measurement for Movement-Related Fields Averaged By Using the Force

Introduction When we measure movement-related MEGs such as movement-related field (MEF) and motor field (MF), electromyogram (EMG) obtained from corresponding muscles has been used as a trigger signal for the alignment of averaging MEGs [1,2]. However, the latency of EMG signals is often distributed inconsistently, ranging from 30msec to 60msec and this fluctuation sometimes makes difficult to analyze the temporal structure of movement-related MEGs [8]. Using signals of the force sensitive register (FSR) may be an alternate approach for a more stable latency fluctuation. FSR has been used to measure the applied force in the ergonomics/biomechanics research area owing to its direct and quick responses [3]. Therefore, it is not hard to imagine that the temporal patterns to illustrate the relationship between force intensity and MEG activity in a sensorimotor area can be clarified. With regard to isometric force exertion, there was a correlation between the force intensity and the int