Lingual resistance training has been proposed as an intervention to improve decreased tongue pressure strength and endurance in patients with dysphagia. However, little is known about the impact of lingual resistance training on swallow physiology. This systematic review scrutinizes the available evidence regarding the effects of lingual resistance training on swallowing function in studies using Videofluoroscopic Swallowing Studies (VFSS) with adults. Seven articles met the inclusion criteria and underwent detailed review for study quality, data extraction, and planned meta-analysis. Included studies applied this intervention to a stroke and brain injury patient populations or to healthy participants, applied different training protocols, and used a number of outcome measures, making it difficult to generalize results. Lingual resistance training protocols included anterior and posterior tongue strengthening, accuracy training, and effortful press against hard palate with varying treatment durations. VFSS protocols typically included a thin barium stimulus along with one other consistency to evaluate the effects of the intervention. Swallowing measures included swallow safety, efficiency, and temporal measures. Temporal measures significantly improved in one study, while safety improvements showed mixed results across studies. Reported improvements in swallowing efficiency were limited to reductions in thin liquid barium residue in two studies. Overall, the evidence regarding the impact of lingual resistance training for dysphagia is mixed. Meta-analysis was not possible due to differences in methods and outcome measurements across studies. Reporting all aspects of training and details regarding VFSS protocols is crucial for the reproducibility of these interventions.
Future investigations should focus on completing robust analyses of swallowing kinematics and function following tongue pressure training to determine efficacy for swallowing function.
Sensory input can alter swallowing control in both the cortex and brainstem. Electrical stimulation of superior laryngeal nerve afferents increases reflexive swallowing in animals, with different frequencies optimally effective across species. Here we determined 1) if neck vibration overlying the larynx affected the fundamental frequency of the voice demonstrating penetration of vibration into the laryngeal tissues, and 2) if vibration, in comparison with sham, increased spontaneous swallowing and enhanced cortical hemodynamic responses to swallows in the swallowing network. A device with two motors, one over each thyroid lamina, delivered intermittent 10-s epochs of vibration. We recorded swallows and event-related changes in blood oxygenation level to swallows over the motor and sensory swallowing cortexes bilaterally using functional near infrared spectroscopy. Ten healthy participants completed eight 20-min conditions in counterbalanced order with either epochs of continuous vibration at 30, 70, 110, 150, and 70 + 110 Hz combined, 4-Hz pulsed vibration at 70 + 110 Hz, or two sham conditions without stimulation. Stimulation epochs were separated by interstimulus intervals varying between 30 and 45 s in duration. Vibration significantly reduced the fundamental frequency of the voice compared with no stimulation demonstrating that vibration penetrated laryngeal tissues. Vibration at 70 and at 150 Hz increased spontaneous swallowing compared with sham. Hemodynamic responses to swallows in the motor cortex were enhanced during conditions containing stimulation compared with sham. As vibratory stimulation on the neck increased spontaneous swallowing and enhanced cortical activation for swallows in healthy participants, it may be useful for enhancing swallowing in patients with dysphagia.NEW & NOTEWORTHY Vibratory stimulation at 70 and 150 Hz on the neck overlying the larynx increased the frequency of spontaneous swallowing. Simultaneously vibration also enhanced hemodynamic responses in the motor cortex to swallows when recorded with functional near-infrared spectroscopy (fNIRS). As vibrotactile stimulation on the neck enhanced cortical activation for swallowing in healthy participants, it may be useful for enhancing swallowing in patients with dysphagia.
To investigate whether patterns of swallowing difficulties were associated with the location of the brain lesion, cognitive function, and severity of stroke in stroke patients.
Seventy-six patients with first-time acute stroke were included in the present investigation. Swallowing-related parameters, which were assessed videofluoroscopically, included impairment of lip closure, decreased tongue movement, amount of oral remnant, premature loss of food material, delay in oral transit time, laryngealelevation, delay in pharyngeal triggering time, presence of penetration or aspiration, and the amount of vallecular and pyriform sinus remnants. The locations of brain lesions were classified into the frontal, parietotemporal, subcortical, medulla, pons, and cerebellum. The degree of cognitive impairment and the severity of stroke were assessed by the Mini Mental Status Examination (MMSE) and the National Institute of Health Stroke Scale (NIHSS), respectively.
An insufficient laryngealelevation, the amount of pyriform sinus, and vallecular space remnant in addition to the incidence of aspiration were correlated with medullary infarction. Other swallowing parameters were not related to lesion topology. Lip closure dysfunction, decreased tongue movement, increased oral remnant and premature loss were associated with low MMSE scores. A delayed oral transit time were associated with NIHSS scores.
In-coordination of the lip, the tongue, and the oropharynx were associated with the degree of cognitive impairment and the stroke severity rather than with the location of the lesion, whereas incomplete laryngealelevation and aspiration were predominant in medullary lesions.
To investigate the relationship between removable dentures and swallowing and describe risks.
Twenty-four patients with removable dentures who were referred for videofluoroscopic swallowing study (VFSS) were enrolled. We evaluated the change of swallowing function using VFSS before and after the removal of the removable denture. The masticatory performance by Kazunori’s method, sensation of oral cavity by Christian’s method, underlying disease, and National Institutes of Health Stroke Scale for level of consciousness were collected. Functional dysphagia scales, including the oral transit time (OTT), pharyngeal transit time (PTT), percentage of oral residue, percentage of pharyngeal residue, oropharyngeal swallow efficiency (OPSE), and presence of aspiration were measured.
Four patients dropped out and 20 patients were analyzed (stroke, 13 patients; pneumonia, 3 patients; and others, 4 patients). The mean age was 73.3±11.4 years. There were significant differences before and after the removal of the denture for the OTT. OTT was significantly less after the removal of the denture (8.87 vs. 4.38 seconds, p=0.01). OPSE increased remarkably after the removal of the denture, but without significance (18.24%/sec vs. 25.26%/sec, p=0.05). The OTT and OPSE, while donning a removable denture, were correlated with the masticatory performance (OTT, p=0.04; OPSE, p=0.003) and sensation of oral cavity (OTT, p=0.006; OPSE, p=0.007).
A removable denture may have negative effects on swallowing, especially OTT and OPSE. These affects may be caused by impaired sensation of the oral cavity or masticatory performance induced by the removable denture.
Purpose of this review is the evaluation of speech and swallowing function after surgical treatment for advanced oral and oropharyngeal carcinoma. A systematic literature search (1993–2009), yielding 1,220 hits. The predefined criteria for inclusion in this systematic review were oral or oropharyngeal cancer, surgical treatment, speech and/or swallow function outcome, T-stage ≥ 2, patient cohort > 20, adequate description of the patient cohort in terms of tumor (sub) site, and low risk of bias (Cochrane criteria). Twelve studies fulfilled the predefined criteria. The results for speech more than 1 year after resection of oral or oropharyngeal cancer are reported to be moderate to good; although in the majority of patients speech is experienced as deviant. Overall sentence intelligibility scores are normal (92–98%). Swallowing is reported to be often already disturbed before treatment and is even more severely compromised after treatment. Aspiration rates of liquids vary from 12 to 50% and especially after oropharyngeal resection, pharyngeal transit times are delayed. Postoperative radiotherapy further increases function disturbances significantly. Critical subsites with regard to speech are the mobile tongue, and the soft palate and for swallowing, the floor of the mouth, the posterior base of tongue and the hard and soft palate. Prosthetic appliances (e.g., obturators, palatal augmentation prostheses) can diminish function losses considerably. Surgery for oral and oropharyngeal cancer yields function deficits, most notably with regard to swallowing. Series are small and outcome measurements vary. Therefore, to optimize pre-operative risk assessment, there is a need for internationally standardized outcome measurements.
Oropharyngeal swallowing is a complex sensorimotor phenomenon that has had decades of research dedicated to understanding it more thoroughly. However, the underlying neural mechanisms responsible for normal and disordered swallowing remain very vague. We consider this gap in knowledge the result of swallowing research that has been broad (identifying phenomena) but not deep (identifying what controls the phenomena). The goals of this review are to address the complexity of motor control of oropharyngeal swallowing and to review the principles of motor learning based on limb movements as a model system. We compare this literature on limb motor learning to what is known about oropharyngeal function as a first step toward suggesting the use of motor learning principles in swallowing research.
(1) To compare the kinematic motion of the hyoid bone and the epiglottis in healthy controls and a sample of patients with dysphagia of different etiologies, and (2) to evaluate the potential value of kinematic swallowing analysis to differentiate the mechanism of dysphagia.
We performed two-dimensional video motion analysis of the hyoid bone using videofluoroscopic images in nine controls without any swallowing difficulty, and seven patients with supratentorial stroke, three patients with inflammatory myopathy who showed dysphagia. Main outcome measures were: (1) horizontal and vertical excursion of the hyoid bone, and rotation of the epiglottis, and (2) trajectory of the hyoid bone and epiglottis during swallowing.
Horizontal excursion of the hyoid bone and rotation of the epiglottis were reduced in patients with myopathy as compared to control and patients with stroke (P<0.05). Patients with dysphagia showed different patterns as compared to control in trajectory analysis according to their etiology.
We conclude that extent and pattern of movement of the hyoid bone and the epiglottis during swallowing were different according to etiology of dysphagia, and swallowing motion analysis could be applied to differentiate the mechanism of dysphagia.