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

Dynamic Range for Bone Conduction Ultrasound

Introduction Since Gavreau [1] reported that ultrasound could be perceived by bone conduction, controversial discussions have surrounded the concept of the auditory perception of ultrasound. Particular attention has been paid to its perception mechanism and to whether or not the profoundly hearingimpaired can detect ultrasound and discriminate ultrasound modulated by different speech sounds. Consideration is being given to the possibility of using ultrasound hearing aids as an alternative to cochlear implant. Pertaining to the peripheral mechanism of ultrasound perception, the following hypotheses were suggested by Dieroff and Ertelsu [2]. 1) Ultrasonic perception as a result of inadequate stimulation of particular sections of the hearing system [3]. 2) Ultrasonic perception as a result of adequate stimulation of particular sections of the hearing system. The second hypothesis was classified into two categories: the existence of rudimentary ultrasonic receptors [4,5] and the generati