Reflex vs. volitional cough differences amongst head and neck cancer survivors characterized by time since treatment and aspiration status.

BACKGROUND: The aim of this study was to investigate differences in reflexive and volitional cough airflows in advanced stage head and neck cancer survivors as it relates to aspiration status and time since treatment. The hypothesis is that those who aspirate several years after treatment completion would demonstrate reduced airflows for all cough parameters compared to those recently status post treatment completion given the known progressive deterioration associated with radiotherapy. METHODS: Demographic and airflow data during both reflexive and volitional cough tasks and aspiration status as determined during fiberoptic endoscopic evaluation of swallow function were collected from 33 Head and Neck Cancer (HNC) survivors. RESULTS: Omnibus MANOVA for dependent airflow variables and independent variables aspiration status, time since treatment and cough type (reflex or volitional) was significant (F(3,1) = 184, p < 0.000) indicating that peak expiratory flow rates (PEFR) were reduced under reflex (mean PEFR 1.88 SD 0.7) versus volitional (mean PEFR 2.3, SD 0.7) cough types; reduced for aspirators versus non-aspirators (F(2,1) = 4.1, p = 0.04) and reduced for those in the subacute versus chronic phase status post Intensity Modulated Radiotherapy (IMRT) (F(2,1) = 10.05, p = 0.002). CONCLUSION: Findings of reduced reflexive compared to volitional cough airflows in head and neck cancer survivors are consistent with those from both healthy and other diseased populations. Additional findings that aspirators demonstrate reduced cough airflows compared to non-aspirators supports the hypothesis. Surprisingly, those recently status post treatment completion show worse cough airflows compared to those remotely status post treatment completion.

Impact of Tussigenic Stimuli on Perceived Upper Airway Sensation and Motor Cough Response Following Total Laryngectomy.

BACKGROUND: Total laryngectomy (TL) is standard intervention for carcinoma of the head and neck or, in cases of non-functional larynx, as a result of disease or radiation exposure. Laryngeal extirpation serves as a unique human model of both recurrent and superior laryngeal nerve section and offers insight into motor and sensory aspects of cough: both volitional and in response to tussigenic stimuli. While motor changes in cough function are expected among those status post-TL due to postoperative reconstruction of the upper airway, motor cough parameters have not been well described and sensory aspects of cough are unknown in this population, which provides insight into a vagal denervation model in humans. METHODS: Data were collected from three groups totaling 80 adults (39 male), including 25 healthy younger adults (HYA), 27 healthy older adults (HOA), and 28 adults post-TL. Cough was elicited both upon command and in response to nebulized capsaicin. Outcome measures included urge to cough and cough airflows. RESULTS: Kruskal-Wallis test showed that two of the three groups differed significantly by urge to cough χ2(2, N = 244) = 8.974, p = 0.011. Post hoc analysis showed that post-TL subjects had reduced perceived urge to cough at all concentrations of capsaicin (p < 0.05). Cough airflows were significantly reduced for post-TL subjects compared to healthy controls in all metrics except post-peak phase integral (PPPI) for which HOA and TLs were comparable under both volitional and capsaicin-induced conditions. CONCLUSIONS: These findings support the hypothesis that both cough airflow and sensations are significantly reduced in post-TL subjects when compared with HOA. Interestingly, HOA and post-TL subjects have comparably reduced UTC and cough airflows when compared to HYA. The only metric of cough airflow for which these groups differ is the PPPI, which may be a compensatory adaptation for reduced cough airflows and/or sensation.

Respiratory-Swallow Pattern Following Total Laryngectomy.

The goal of this study was to further characterize respiratory patterns in total laryngectomees with attention to respiratory-swallow pattern as it relates to presence/absence of tracheoesophageal puncture (TEP) and bolus consistency. It was hypothesized that participants with TEP would exhibit respiratory-swallow patterns that were significantly different than those without TEP and that bolus consistency (thin or solid) would modulate respiratory-swallow pattern. Data were collected from 12 adults (8 male), aged 46-67 years (mean 57) status post total laryngectomy (1-30 years; average 6 years). Those actively receiving chemoradiation, with history of esophageal cancer, with neurologic disease, with history of lung cancer, with known or suspected recurrence of head and neck cancer (HNC), or with severe cognitive deficits were excluded. Laryngectomy participants were asked to swallow three sips of water and three bites of graham cracker. Submental surface EMG activity was used to detect swallows and a custom stoma mask in line with a pneumotachograph measured airflow during the swallows. Non-parametric Mann-Whitney test for differences was used to detect significance for our dependent variables, TEP or bolus consistency and independent variables, respiratory-swallow pattern. Laryngectomee's showed preference for swallow during inspiration which is inconsistent with the expiratory pattern preference found in healthy adults with intact larynges by McFarland et al. (Respir Physiol Neurobiol 234:89-96, 2016) but consistent with the pattern preference for inspiration (or non-dominant respiratory-swallow phase pattern) found in the HNC population at-large by Brodsky et al. (J Appl Physiol 112(10):1698-1705, 2012). No significant difference was found in swallow pattern with regards to presence/absence of TEP or bolus consistency.