Impaired swallowing mechanics of post radiation therapy head and neck cancer patients: A retrospective videofluoroscopic study

AIM: To determine swallowing outcomes and hyolaryngeal mechanics associated with post radiation therapy head and neck cancer (rtHNC) patients using videofluoroscopic swallow studies.METHODS: In this retrospective cohort study, videofluoroscopic images of rtHNC patients (n = 21) were compared with age and gender matched controls (n = 21). Penetration-aspiration of the bolus and bolus residue were measured as swallowing outcome variables. Timing and displacement measurements of the anterior and posterior muscular slings elevating the hyolaryngeal complex were acquired. Coordinate data of anatomical landmarks mapping the action of the anterior muscles (suprahyoid muscles) and posterior muscles (long pharyngeal muscles) were used to calculate the distance measurements, and slice numbers were used to calculate time intervals. Canonical variate analysis with post-hoc discriminant function analysis was performed on coordinate data to determine multivariate mechanics of swallowing associated with treatment. Pharyngeal constriction ratio (PCR) was also measured to determine if weak pharyngeal constriction is associated with post radiation therapy.RESULTS: The rtHNC group was characterized by poor swallowing outcomes compared to the control group in regards to: Penetration-aspiration scale (P < 0.0001), normalized residue ratio scale (NRRS) for the valleculae (P = 0.002) and NRRS for the piriform sinuses (P = 0.003). Timing and distance measurements of the anterior muscular sling were not significantly different in the two groups, whereas for the PMS time of displacement was abbreviated (P = 0.002) and distance of excursion was reduced (P = 0.02) in the rtHNC group. A canonical variate analysis shows a significant reduction in pharyngeal mechanics in the rtHNC group (P < 0.0001). The PCR was significantly higher in the test group than the control group (P = 0.0001) indicating reduced efficiency in pharyngeal clearance.CONCLUSION: Using videofluoroscopy, this study shows rtHNC patients have worse swallowing outcomes associated with reduced hyolaryngeal mechanics and pharyngeal constriction compared with controls.     

Timing of glottic closure during swallowing: a combined electromyographic and endoscopic analysis

OBJECTIVES: We performed a case series to enhance our understanding of the coupling between neuromuscular events and glottic closure. METHODS: We performed combined flexible video laryngoscopy and electromyography in 4 healthy human subjects. Hooked-wire electrodes were placed in the superior pharyngeal constrictor, longitudinal pharyngeal, cricopharyngeus, thyroarytenoid, genioglossus, suprahyoid, and posterior cricoarytenoid muscles. A flexible endoscope tip was positioned in the oropharyngeal-hypopharyngeal region. The subjects performed multiple trials each of 10-mL normal and super-supraglottic liquid swallows. RESULTS: Arytenoid movement consistently preceded full glottic closure and was associated with cessation of activity of the posterior cricoarytenoid muscle. In 89% of normal swallows, the glottis was partially open in the video frame before bolus passage. The maximum amount of thyroarytenoid electromyographic activity occurred during endoscopic whiteout. When subjects executed a super-supraglottic swallow, early thyroarytenoid activity coincided with arytenoid contact. CONCLUSIONS: The initial medialization of the arytenoids is due to a decrease in motor tone of the posterior cricoarytenoid muscle. Full glottic closure typically occurs late in the process of swallowing, with activation of the thyroarytenoid muscle. Shifting of arytenoid medialization and glottic closure earlier in the super-supraglottic swallow indicates that glottic closure is under significant voluntary control.     

A Survey of Variables Used by Speech-Language Pathologists to Assess Function and Predict Functional Recovery in Oral Cancer Patients

Oromotor and clinical swallow assessments are routinely performed by speech-language pathologists (SLPs) who see head and neck cancer (HNC) patients. However, the tools used to assess some of these variables vary. SLPs routinely identify and quantify abnormal functioning in order to rehabilitate the patient. However, function in terms of tongue range of motion (ROM) is typically described using a subjective severity rating scale. The primary objective of this study was to gain insight via survey into what variables SLPs consider important in assessing and documenting function after HNC treatment. A second objective was to seek feedback regarding a scale designed by the authors for assessing tongue ROM for this cohort of patients. This survey also was developed to elucidate salient factors that might have an impact on the prognosis for speech and swallow outcomes. Of the 1,816 SLPs who were sent the survey, 292 responded who work with HNC patients. Results revealed that although 95 % of SLPs assess tongue strength, only 13 % use instrumental methods. Although 98 % assess tongue ROM, 88 % estimate ROM based on clinical assessment. The majority of respondents agreed with the utility of the proposed tongue ROM rating scale. Several variables were identified by respondents as having an impact on overall prognosis for speech and swallow functioning. Tracking progress and change in function with treatment can be accomplished only with measurable assessment techniques. Furthermore, a consistent measuring system can benefit patients with other diagnoses that affect lingual mobility and strength.