Introduction
Early detection and treatment of dysphagia is critical in post-stroke patients because it is associated with various medical complications, including aspiration pneumonia, malnutrition, and increased mortality. Anatomical lesions related to dysphagia varied from oral to esophagus including the tongue. The role of tongue includes the bolus formation, placement in the oral phase, the transfer of a bolus from the oral cavity to the pharyngeal cavity, and retraction against the pharyngeal walls to assist in moving the bolus into the upper esophageal sphincter during the pharyngeal phase. Therefore, a decrease in the strength of the tongue observing in stroke or head and neck cancer patients closely related to the occurrence of oropharyngeal dysphagia. As the tongue is composed of muscle groups, not bones, the length of the tongue may reflect the strength of it. Recent study suggested that maximal tongue protrusion is related to both suprahyoid muscle activation and intrinsic tongue muscle strength. In this study, we investigated the relationship between maximal tongue protrusion length and dysphagia in stroke patients.
Methods
This study was designed as cross sectional study. All participants underwent tongue length examination and video-fluoroscopic swallowing study (VFSS). Tongue length was evaluated in 2 ways; passive tongue length (PTL) in resting state and maximal tongue protrusion length (MTPL) in maximal volition. PTL was defined as the length from tongue tie to the tip of the tongue in resting state, following Kotlow’s free tongue measurement. The distance between the maximally protruded tongue tip and the upper incisors was measured as each subject’s MTPL. PTL and MTPL, which were measured by a blinded examiner, were evaluated 5 times at each and the average value was used for analysis, excluding the maximum and minimum values. Because tongue length varies from person to person, we calculated the ratio of MTPL to PTL (RMP) to reflect the difference. The findings of VFSS were scored using the Penetration-Aspiration Scale (PAS). Bivariate analysis and regression lines for PTL, MTPL, RMP, and PAS were calculated. Statistical significance was set at p<0.05.
Results
10 post-stroke patients were recruited in this study. Baseline characteristics of participants are summarized in Table 1. Bivariate analysis and regression lines for PTL and PAS score, MTPL and PAS score, RMP and PAS score was calculated. There was no significant relationship between PTL and PAS score (p=0.685). MTPL and RMP showed significant inverse relationship with PAS score (MTPL; p=0.009, RMP; p=0.013) (Fig 1-2). Interestingly, no aspiration was observed in patients with RMP over 1.5.
Conclusion
RMP can be used as a screening test for oropharyngeal dysphagia in stroke patients. We need further investigation with more participants to establish a clear cut off value for prediction of dysphagia. |
