Laryngeal Closure during Swallowing in Stroke Survivors with Cortical or Subcortical Lesion.

BACKGROUND: One of the major, and most harmful, symptoms of dysphagia in stroke survivors is aspiration. Survivors of unilateral cortical strokes with dysphagia and resulting aspiration have been reported to have greater initiation delays in laryngeal closure than those who did not aspirate. Few studies have reported such data in survivors of subcortical stroke. METHODS: This study measured initiation of laryngeal closure (ILC) and laryngeal closure duration (LCD) in 2 groups of subjects: 15 stroke survivors with cortical lesions and 15 stroke survivors with subcortical lesions. Means and standard deviations of ILC and LCD were analyzed on 5-mL thin liquid and 5-mL puree boluses using a 100-ms timer during subsequent analysis of videofluoroscopic swallowing examinations. Statistical comparisons were used by repeated measures analysis of variance. Significance level was set at P < .05. RESULTS: ILC was significantly longer in stroke survivors with a subcortical lesion than in those with a cortical lesion for both bolus consistencies. However, there were no significant differences between the 2 groups in LCD. Stroke survivors with a subcortical lesion had a greater incidence of penetration or aspiration and silent aspiration than those with a cortical lesion and a longer delay in the ILC. CONCLUSIONS: Subcortical lesions may put these survivors at greater risk of aspiration due to delayed initial laryngeal closure and reduced oral and laryngeal sensation. The subcortical damage, which occurs at the basal ganglia, may interrupt the ILC.

Effects of tongue pressing effortful swallow in older healthy individuals.

INTRODUCTION: The risk of swallowing disorders is increased for older individuals due to weak tongue and pharyngeal muscle strength. This study was appraised the value of a preventative approach by developing the tongue pressing effortful swallow (TPES) applied using a home-based and self-administered procedure. The TPES was developed by combining two swallowing exercises: tongue strengthening exercise and the effortful swallow. The purpose of this study was to examine the effects of the TPES on maximum tongue pressure and peak amplitude of submental muscle activity in older individuals. MATERIAL AND METHODS: 27 older individuals (mean 73 years) performed a 4-week TPES. The exercise program was adapted to a home-based and self-administered procedure. The maximum tongue pressure was measured by the Iowa Oral Performance Instrument and peak amplitude of submental muscle activity by surface electromyography (sEMG). Statistical comparisons were made by a matched pairs t-test (p<0.05). RESULTS: The results of this study showed that the TPES had statistically significant and positive effects on increasing maximum tongue pressure, but the peak amplitude of the submental sEMG did not differ between before and after exercises. CONCLUSIONS: The TPES had a positive impact in older individuals. The TPES, a combining exercise, was possible because two exercises had common physiological events. The TPES was a more innovative and efficient approach than the tongue strengthening exercise alone. In addition, older individuals were able to perform the swallowing exercise at home and by themselves with little assistance. Future research needs to refine the TPES and apply it to patients with dysphagia.

The Relation Between the Presence of Aspiration or Penetration and the Clinical Indicators of Dysphagia in Poststroke Survivors.

OBJECTIVE: To examine the relation between the presence of penetration or aspiration and the occurrence of the clinical indicators of dysphagia. The presence of penetration or aspiration is closely related to the clinical indicators of dysphagia. It is essential to understand these relationships in order to implement proper diagnosis and treatment of dysphagia. METHODS: Fifty-eight poststroke survivors were divided into two groups: patients with or without penetration or aspiration. Medical records and videofluoroscopic swallowing examinations were reviewed. The occurrence of clinical indicators of dysphagia between two groups was analyzed with Cross Tabulation and the Pearson chi-square test (p<0.05). RESULTS: Poststroke survivors with penetration or aspiration had significantly high occurrences of delayed initiation of the swallow (p=0.04) and reduced hyolaryngeal elevation (p<0.01) than those without penetration or aspiration. CONCLUSION: The results of this study indicate that delayed initiation of the swallow is a strong physiological indicator of penetration or aspiration during the oral stage of swallowing in poststroke survivors. For the pharyngeal stage of swallowing, hyoid and laryngeal elevation is a key event related to occurrence of penetration or aspiration. Clinical indicators should be investigated further to allow appropriate implementation of treatment strategies for stroke survivors.

Upper esophageal sphincter opening during swallow in stroke survivors.

OBJECTIVE: Timely and efficient upper esophageal sphincter (UES) opening may be critical to safe transport of food or liquid to the stomach and to prevent aspiration during the swallow. The purpose of this study was to examine the temporal and biomechanical characteristics of the UES opening in stroke survivors. METHOD: Maximum duration and width of the UES opening were obtained from 15 stroke survivors with aspiration and 15 stroke survivors with no aspiration. The control group was composed of 15 normal subjects undergoing videofluoroscopic swallowing examinations. The videofluoroscopic swallowing examination protocol was as follows: two swallows of 5 ml thin liquid and two swallows of 10 ml thin liquid. Statistical comparisons were made by repeated measurements of analysis of variance, and the significance level was set at P < 0.025. RESULT: The stroke survivors with aspiration, the stroke survivors without aspiration, and the control group differed significantly for duration of UES opening (P < 0.01) but not maximum width of UES opening. CONCLUSION: Prolonged UES opening may be related to prolonged pharyngeal transition of the bolus and slower UES muscle contraction and hyolaryngeal excursion after stroke.

Oropharyngeal transition of the bolus in post-stroke patients.

OBJECTIVE: The purposes of this study were to determine whether two bolus transition durations (oral transit time and pharyngeal transit time) were different during oropharyngeal swallowing in post-stroke patients who aspirated and who did not aspirate and to examine those differences across varying bolus viscosities. DESIGN: Means and standard deviations of oral transit time and pharyngeal transit time were analyzed on 5 ml of thin and nectar thick liquids and puree swallows from videofluoroscopic swallowing examinations of 30 post-stroke patients. Statistical comparisons were made by repeated measures analysis of variance, with the within-subject variable being the three consistencies and the between-subject variable being the two groups. Significance level was set at P < 0.025. RESULTS: Oral transition of the bolus did not differ between the two patient groups. Pharyngeal transition of the bolus differentiated the patients who aspirated from the patients who did not aspirate. Both the oral and pharyngeal transitions differed significantly for the puree compared with the thin and nectar thick liquids. CONCLUSIONS: Patients who demonstrate prolonged pharyngeal transit times may be at risk for aspiration.

Initiation and duration of laryngeal closure during the pharyngeal swallow in post-stroke patients.

As a bolus enters the pharynx during the swallow, the airway is protected by laryngeal closure, a process characterized by approximation of the vocal folds plus approximation of the arytenoid cartilages to the base of the epiglottis. The purpose of this study was to measure initiation of laryngeal closure (ILC) and laryngeal closure duration (LCD) in three groups of subjects: (1) ten stroke patients who aspirated before and during the swallow (aspirators), (2) ten stroke patients who did not aspirate (nonaspirators), and (3) ten normal control subjects. Means and standard deviations of ILC and LCD were analyzed for both 5-ml and 10-ml thin-liquid boluses using a 100-ms timer during subsequent analysis of videofluoroscopic swallowing examinations. There were significant differences between aspirators and control subjects for both ILC and LCD, and significant differences between aspirators and nonaspirators for ILC. There were no significant differences between aspirators and nonaspirators for LCD. Both delayed ILC and reduced LCD were associated with post-stroke aspiration. Delayed ILC is a significant indicator of overall risk of aspiration. Clinical implications for these findings are discussed.