Objective: To characterize the repetitive transcranial magnetic stimulation (rTMS) induced changes in angiogenic mechanisms across different brain regions. Methods: Seventy-nine adult male Sprague-Dawley rats were subjected to a middle cerebral artery occlusion (day 0) and then treated with 1-Hz, 20-Hz, or sham stimulation of their lesioned hemispheres for 2 weeks. The stimulation intensity was set to 100% of the motor threshold. The neurological function was assessed on days 3, 10, and 17. The infarct volume and angiogenesis were measured by histology, immunohistochemistry, Western blot, and real-time polymerase chain reaction (PCR) assays. Brain tissue was harvested from the ischemic core (IC), ischemic border zone (BZ), and contralateral homologous cortex (CH). Results: Optical density of angiopoietin1 and synaptophysin in the IC was significantly greater in the low-frequency group than in the sham group (p=0.03 and p=0.03, respectively). The 1-Hz rTMS significantly increased the level of Akt phosphorylation in the BZ (p<0.05 vs. 20 Hz). Endothelial nitric oxide synthase phosphorylation was increased in the IC (p<0.05 vs. 20 Hz), BZ (p<0.05 vs. 20 Hz), and CH (p<0.05 vs. 20 Hz and p<0.05 vs. sham). Real-time PCR demonstrated that low-frequency stimulation significantly increased the transcriptional activity of the TIE2 gene in the IC (p<0.05). Conclusion Low-frequency rTMS of the ipsilesional hemisphere in the early subacute phase of stroke promotes the expression of angiogenic factors and related genes in the brain, particularly in the injured area.

Objective: To evaluate the reliability of suprahyoid and infrahyoid electromyography (EMG) measurement during swallowing. Methods: In all, 10 healthy volunteers were evaluated for the following surface EMG (sEMG) parameters in the suprahyoid and infrahyoid muscles during swallowing: onset latency, offset latency, duration, peak latency, maximal amplitude during swallowing, and the area under curve (AUC) of the rectified EMG signal. The sEMG was recorded while the participants swallowed five times each of the four fluid volumes (saliva, 2 ml, 5 ml, and 20 ml of water), totaling to 20 swallows. Moreover, the intra-participant variability per parameter was evaluated using the coefficient of variation (CV). Results: Suprahyoid muscles were activated 0.095 s (95% CI, 0.062-0.128) earlier than the infrahyoid muscles.Maximal amplitudes during the 20 ml swallow were 17.484 (−1.543-36.512) and 13.490 (1.254-25.727) μV higher than values obtained during the 2 ml swallow in the suprahyoid and infrahyoid muscles, respectively. Furthermore, the AUC of the rectified EMG signal increased with the volume of swallow in both muscle groups (P=0.003, suprahyoid; P＜0.002, infrahyoid). The intra-individual variabilities of offset latency, duration, and maximal amplitude were relatively low (＜30% CV) in both muscle groups with respect to other parameters. The assessment of each parameter using EMG was highly reliable, with an intraclass correlation coefficient of ＞0.8. Conclusion Among the variable sEMG parameters assessed, the offset latency, duration, and maximal amplitude were the least variable. Although reliability on the rater side showed good results, the swallow-to-swallow variability of the parameters need to be considered in swallowing studies using sEMG.

Objective: To evaluate the reliability of suprahyoid and infrahyoid electromyography (EMG) measurement during swallowing. Methods: In all, 10 healthy volunteers were evaluated for the following surface EMG (sEMG) parameters in the suprahyoid and infrahyoid muscles during swallowing: onset latency, offset latency, duration, peak latency, maximal amplitude during swallowing, and the area under curve (AUC) of the rectified EMG signal. The sEMG was recorded while the participants swallowed five times each of the four fluid volumes (saliva, 2 ml, 5 ml, and 20 ml of water), totaling to 20 swallows. Moreover, the intra-participant variability per parameter was evaluated using the coefficient of variation (CV). Results: Suprahyoid muscles were activated 0.095 s (95% CI, 0.062-0.128) earlier than the infrahyoid muscles.Maximal amplitudes during the 20 ml swallow were 17.484 (−1.543-36.512) and 13.490 (1.254-25.727) μV higher than values obtained during the 2 ml swallow in the suprahyoid and infrahyoid muscles, respectively. Furthermore, the AUC of the rectified EMG signal increased with the volume of swallow in both muscle groups (P=0.003, suprahyoid; P＜0.002, infrahyoid). The intra-individual variabilities of offset latency, duration, and maximal amplitude were relatively low (＜30% CV) in both muscle groups with respect to other parameters. The assessment of each parameter using EMG was highly reliable, with an intraclass correlation coefficient of ＞0.8. Conclusion Among the variable sEMG parameters assessed, the offset latency, duration, and maximal amplitude were the least variable. Although reliability on the rater side showed good results, the swallow-to-swallow variability of the parameters need to be considered in swallowing studies using sEMG.

Objective: To analyze the rheological and biochemical properties of saliva in healthy adults. Methods: The subjects were seven healthy young adults (20-39 years). The whole saliva was collected by the spitting method between 9:00 am and 12:00 am. Unstimulated saliva was collected first, which was followed by the collection of stimulated saliva using citric acid was collected. The viscosity was measured using a capillary viscometer to examine the rheological properties. The MUC5B concentration was analyzed using an enzyme-linked immunosorbent assay (ELISA) for the biochemical properties. Results: Ten and five minutes were required on average for unstimulated saliva and stimulated saliva, respectively, to collect the minimum amount needed for analysis (8 ml). The flow rate increased from 1.037±0.323 ml/min to 1.823± 0.660 ml/min after stimulation (P=0.018). Citric acid stimulation also increased the MUC5B concentration in the saliva from 3.706±3.575 μg/ml to 6.928±2.03 μg/ml (P=0.028). The viscosity of saliva, however, did not show a significant difference between with (1.1±0.164 cSt) or without (1.019±0.08 cSt) stimulation (P=0.128). A positive correlation was observed between the flow rate and MUC5B concentration (Spearman’s rho=0.547, P=0.043). On the other hand, there was no significant correlation between the MUC5B concentration and viscosity both in the unstimulated and stimulated saliva (P=0.939 and 0.819, respectively). Conclusion No significant correlation was observed between the MUC5B concentration and viscosity. Considering the time required to collect samples, an analysis of the stimulated saliva appears feasible in various research settings.The feasibility of these analysis methods should be examined in a patient population.

Objective: The purpose of this study was to understand the mechanism of normal hyoid movement during swallowing by calculating the activity of each muscle involved in the hyoid movement and propose a new kinetic modeling of hyoid movement using videofluoroscopy images. Methods: Eight healthy volunteers with an average age of 56.8 swallowed 2-ml of diluted barium under videofluoroscopy. A video image was digitized to analyze the movement of the hyoid bone. The activity of the muscles acting on the hyoid bone was calculated from the movement of the hyoid bone using kinetic modeling. A surface electromyogram was measured simultaneously with videofluoroscopy, and the muscle force calculated by kinetic modeling was compared with the muscle force measured by surface EMG. Results: The muscles acting on the hyoid bone were divided into three groups according to the direction of force and analyzed. The contraction of the retractor muscle group was observed as a median of 433 ms (95% CI 264-602, P=0.012) earlier than the contraction of protractor muscle group in all subjects. Generally, the peak activity of each muscle group was observed in the order of retractor (0 ms), protractor (592 ms, 95% CI 429-755), and depressor (717 ms, 95% CI 535-899) muscle group. The contraction of the protractor muscle measured by surface electromyography showed an earlier onset latency with a median of 82 2 ms (95% CI 615-102 9, P=0.012 ) compared to the contraction of the protractor muscle calculated by kinetic modeling. Conclusion Kinetic modeling reflects the pattern of contraction in the order of retractor, protractor, depressor muscle groups, as previously known. And it was possible to evaluate the activity of the retractor muscle, which is difficult to evaluate by electromyogram.

Objective: To evaluate the longitudinal changes of swallowing kinematics based on videofluoroscopic swallowing studies (VFSSs) in subacute stroke patients grouped according to the method of dietary intake. Methods: Sixty-nine subacute stroke patients who had taken at least 2 successive VFSSs were included. Subjects were allocated into 3 groups according to the degree of swallowing function recovery—not improved group (tube feeding recommended to patients at both studies), improved group (tube feedings recommended initially to patients and oral feeding recommended at follow-up study), and well-maintained group (oral feeding at both studies recommended to patients). Initial VFSS was performed during the subacute stage of stroke, 1 to 12 weeks after the onset of stroke, and follow-up VFSS was performed at least once. Kinematic variables were calculated by two-dimensional motion analysis of multiple structures, including the hyoid bone, epiglottis, and vocal cord. Changes of kinematic variables were analyzed in serial VFSSs. Results: At the initial VFSS, the well-maintained group showed significantly larger angles of epiglottic folding than the not improved group, while at the follow-up VFSS, the improved and the well-maintained groups showed significantly larger epiglottic folding angles than the not improved group. The distribution of epiglottic folding angles was in a dichotomous pattern, and each cluster was related to the swallowing function. Conclusion This study showed that improved epiglottic folding angles are associated with the recovery of the swallowing process and suitability for oral feeding among various kinematic variables in subacute stroke patients.

OBJECTIVE: To investigate the proportion of aspiration pneumonia cases among patients with community-acquired pneumonia in Korea. METHODS: This retrospective study included patients with community-acquired pneumonia who had been admitted to the emergency department of a university-affiliated tertiary hospital in Gyeonggi Province, Korea between January 1, 2016 and December 31, 2016. Among these patients, those with aspiration pneumonia were identified using ICD-10 codes (J69.*). Patients with recurrent pneumonia were excluded, as were those who were immunocompromised. The proportion of cases of aspiration pneumonia was calculated, and the characteristics and clinical outcomes of patients with aspiration pneumonia and non-aspiration pneumonia were compared. RESULTS: The proportion of aspiration pneumonia cases among patients with community-acquired pneumonia was 14.2%. Patients with aspiration pneumonia were significantly more likely to be older (p<0.001) and male (p<0.001), and to have a higher confusion, uremia, respiratory rate, blood pressure, and age ≥65 years (CURB-65) score (p<0.001) as compared to patients with non-aspiration pneumonia. They were also more likely to require admission to the intensive care unit (p<0.001) and a longer hospital stay (p<0.001). CONCLUSION: Aspiration pneumonia accounts for 14.2% of all cases of community-acquired pneumonia in Korea. These data may contribute to the establishment of healthcare strategies for managing aspiration pneumonia among Korean adults.
Adult ; Blood Pressure ; Community-Acquired Infections ; Delivery of Health Care ; Emergency Service, Hospital ; Gyeonggi-do ; Humans ; Intensive Care Units ; International Classification of Diseases ; Korea ; Length of Stay ; Male ; Pneumonia ; Pneumonia, Aspiration ; Respiratory Rate ; Retrospective Studies ; Tertiary Care Centers ; Uremia

OBJECTIVE: To investigate the differences in hyolaryngeal kinematics at rest and during swallowing in the upright sitting (UP) and the lateral decubitus (LD) postures in healthy adults, and delineating any potential advantages of swallowing while in the LD posture. METHODS: Swallowing was videofluoroscopically evaluated in 20 healthy volunteers in UP and LD postures, based on the movements of hyoid bone, vocal folds, and the bolus head. Parameters included the Penetration-Aspiration Scale (PAS), horizontal and vertical displacement, horizontal and vertical initial position, horizontal and vertical peak position, time to peak position of the hyoid bone and vocal folds, and pharyngeal transit time (PTT). RESULTS: Nine participants were rated PAS 2 in the UP and 1 was rated PAS 2 in the LD (p=0.003) at least 1 out of 3 swallows each posture. The hyoid and vocal folds showed more anterior and superior peak and initial positions in the LD. In addition, swallowing resulted in greater vertical and smaller horizontal displacement of the hyoid in LD posture compared with UP. Time to peak position of the hyoid was shorter in LD. The maximal vertical and horizontal displacement of the vocal folds, and PTT were comparable between postures. CONCLUSION: The results showed that the peak and initial positions of the hyoid and larynx and the pattern of hyoid movement varied significantly depending on the body postures. This study suggests that the LD posture was one of the safe feeding postures without any increased risk compared with UP posture.
Adult ; Biomechanical Phenomena ; Deglutition Disorders ; Deglutition* ; Head ; Healthy Volunteers ; Humans ; Hyoid Bone ; Larynx ; Posture* ; Swallows ; Vocal Cords

OBJECTIVE: This study evaluated the temporal variables of hyolaryngeal movements during normal swallowing using kinematic analysis of the video fluoroscopic swallowing study (VFSS) to present the normal cut-off values of those variables. METHODS: Seventy-five healthy volunteers (17 men, 58 women) without swallowing dysfunctions were recruited to examine the swallowing of 2-ml diluted barium by a VFSS. Kinematic analysis was conducted by digitization of video files for movements of hyolaryngeal structures, including the vocal cords, hyoid bone, and epiglottis during normal swallowing. The time points and duration of hyolaryngeal movements were measured. The time points were the start point, maximal point, and the end point of the LE (Laryngeal Elevation), HE (Hyoid Excursion), and EF (Epiglottic Folding). The durations of LE, HE, and EF were obtained by subtracting the time of the start point from the time of the maximal point. The onset time of LE was defined as the reference time point (0 sec). The upper and lower limits of the 95% confidence interval were adopted as the normal cut-off values for the temporal variables of hyolaryngeal movements after transformation to a normal distribution. If a transformation formula to a normal distribution was not found in a variable, the values of the 2.5–97.5 percentile were adopted. RESULTS: The cut-off values of the maximal and end points of the LE were 0.281 to 0.916 sec, and 0.830 to 2.205 sec, respectively. The cut-off values of the start, maximal and end points of the HE were −0.233 to 0.400 sec, 0.320 to 0.874 sec, and 0.889 to 2.055 sec, respectively. The cut-off values of the start, maximal, and end points of the EF were 0.017 to 0.483 sec, 0.364 to 1.055 sec, and 0.774 to 1.773 sec, respectively. The cut-off values of the duration of LE, HE, and EF were 0.281 to 0.916 sec, 0.258 to 0.767 sec, and 0.255 to 0.787 sec, respectively. CONCLUSION: This study presented the normal cut-off values of temporal variables of hyolaryngeal movements during normal swallowing. This study can serve as a basis for classifying and analyzing the patterns of patients with dysphagia.
Barium ; Deglutition Disorders ; Deglutition* ; Epiglottis ; Healthy Volunteers ; Humans ; Hyoid Bone ; Male ; Vocal Cords

OBJECTIVE: This study was conducted to evaluate the influence of supraglottic swallowing maneuver on swallowing kinematics using kinematic analysis of a videofluoroscopic swallowing study (VFSS). METHOD: Twenty healthy volunteers (10 in a young group ( < 40 years) and 10 in an elderly group (≥60 years)), participated in this study. After structured instruction by a skilled physician, the subjects swallowed 5 ml of diluted barium in the neutral position without any swallowing maneuvers, as well as with supraglottic swallow maneuver under digital videofluoroscopy, three times each. Kinematic analysis was conducted by digitization of video files for movements of hyolaryngeal structures, including the hyoid bone, larynx, arytenoid, and epiglottis. We measured the maximum displacements and velocities of the hyolaryngeal structures during swallowing. RESULT: The most remarkable change in supraglottic swallow was the maximum vertical displacement (mm) of the hyoid bone during swallowing in both groups (11.5±3.34–19.7±6.88 in the young group, P=0.009; 13.4±2.13–22.8±5.35 in the elderly group, P < 0.001). For velocity variables, patterns of change differed between the young and elderly groups. In the young group, the maximum vertical velocities of the larynx and arytenoid were decreased (P < 0.05), but in the elderly group, the maximum 2D velocity of hyoid bone, maximum horizontal and 2D velocity of the larynx and maximum horizontal velocity of the arytenoid were increased (P < 0.05). There were no significant differences in changes between the young and elderly groups. CONCLUSION: This study showed that supraglottic swallow could affect hyolaryngeal movements, particularly vertical hyoid movement, during swallowing. Beneficial kinematic changes in supraglottic swallow were more pronounced in the elderly group. Therefore, supraglottic swallow may contribute to swallowing improvement by enhancing hyolaryngeal movements during swallowing, in addition to laryngeal closure.
Aged ; Barium ; Biomechanical Phenomena ; Deglutition ; Epiglottis ; Healthy Volunteers ; Humans ; Hyoid Bone ; Larynx ; Methods