A framework for understanding shared substrates of airway protection

Deficits of airway protection can have deleterious effects to health and quality of life. Effective airway protection requires a continuum of behaviors including swallowing and cough. Swallowing prevents material from entering the airway and coughing ejects endogenous material from the airway. There is significant overlap between the control mechanisms for swallowing and cough. In this review we will present the existing literature to support a novel framework for understanding shared substrates of airway protection. This framework was originally adapted from Eccles' model of cough28 (2009) by Hegland, et al.42 (2012). It will serve to provide a basis from which to develop future studies and test specific hypotheses that advance our field and ultimately improve outcomes for people with airway protective deficits

Peak Morphology and Scalp Topography of the Pharyngeal Sensory-Evoked Potential

Abstract The initiation of the pharyngeal stage of swallowing is dependent upon sensory input to the brainstem and cortex. The event-related evoked potential provides a measure of neuronal electrical activity as it relates to a specific stimulus. Air-puff stimulation to the posterior pharyngeal wall produces a sensory-evoked potential (PSEP) waveform. The goal of this study was to characterize the scalp topography and morphology for the component peaks of the PSEP waveform. Twenty-five healthy men and women served as research participants. PSEPs were measured via a 32-electrode cap (10-20 system) connected to SynAmps2 Neuroscan EEG System. Air puffs were delivered directly to the oropharynx using a thin polyethylene tube connected to a flexible laryngoscope. The PSEP waveform is characterized by four early-and mid-latency component peaks: an early positivity (P1) and negativity (N1), followed by a midlatency positivity (P2) and negativity (N2). The early positive peak P1 is localized bilaterally to the lateral parietal scalp, the N1 medially in the frontoparietal region, and the P2 and N2 with diffuse scalp locations. Somatosensory and premotor regions are possible anatomical correlates of peak locations. Based on the latencies of the peaks, they are likely analogous to somatosensory-and respiratory-related evoked potential peaks

Negative emotional stimulation decreases respiratory sensory gating in healthy humans

We tested the hypothesis that negative emotions decrease the respiratory-related evoked potentials (RREP) sensory gating (RSG). RREP were elicited by paired inspiratory occlusions. RSG was calculated as the difference in the averaged RREP peak N1 amplitude between the second (S2) and the first occlusion (S1). RSG was compared between unpleasant and neutral emotional conditions elicited by viewing affective pictures from the IAPS system in thirteen healthy adults. Results are expressed as median [min; max]. Compared to neutral pictures, viewing unpleasant pictures decreased the RREP N1(S1) amplitude (-3.37μV [-4.62; -1.37] versus -4.59μV [-6.08; -1.36]; p=0.017) but not the RREP N1(S2) amplitude (-0.26 [-3.24; 2.36] versus -0.7 [-1.54; 3.6]; p=0.68), and reduced the difference score S2-S1 (3.73μV [0; 5.82] versus 4.79μV [3; 6.2]; p=0.038). We concluded that a negative emotional stimulation could attract subject's attention to the detriment of the respiratory sensory inputs and produced an overall decrease in the RSG. This latter finding might participate in an over-perception of repeatedly presented respiratory stimuli.publisher: Elsevier articletitle: Negative emotional stimulation decreases respiratory sensory gating in healthy humans journaltitle: Respiratory Physiology & Neurobiology articlelink: http://dx.doi.org/10.1016/j.resp.2014.08.019 content_type: article copyright: Copyright © 2014 Elsevier B.V. All rights reserved.status: publishe