S-3-11-02
MATHEMATICAL MODELING OF PHARYNGEAL BOLUS TRANSPORT
Michael W. Chang, M.D., Ph.D. (University of Washington, Seattle, WA, U.S.A.)
Brigette Rosendall, Ph.D., Bruce Finlayson, Ph.D.
Dysphagia is a common clinical symptom which causes serious pulmonary complications such as choking, and aspiration pneumonia. Pharyngeal swallowing involves complex actions that must be properly coordinated to avoid laryngeal penetration. Many factors affect laryngeal penetration, and the interplay of these factors cannot be thoroughly investigated with barium videofluorography (VFG). Consequently, current clinical assessments cannot derive safe guidelines for oral feeding. However, it is important to timely advance patients toward oral feeding in order to enhance the recovery of swallowing and preserve quality of life. Mathematical modeling of pharyngeal bolus transport emerges as a promising method for improving our understanding of swallowing. A computational fluid dynamics software was used to solve the equations of motion that mathematically describe bolus movement. Lateral view of VFG images allowed us to determine the motion of the pharyngeal chamber and construct a two-dimensional model. We investigated the effects of many factors on the normal swallow. Bolus viscosity was found to have the most profound effect. The head of the bolus for a low-viscosity fluid moves faster than that of a high-viscosity fluid, so a low-viscosity fluid is more likely to reach the larynx before it can close. Recirculations form during the swallowing of low-viscosity fluids, but not when high-viscosity fluids are swalloed. These recirculations plus fast arrival could contribute to laryngeal penetration. Dysphagic patients often have the most trouble with low-viscosity fluids, and their diets are commonly restricted to thick liquids, a practice that is supported by the modeling results. On the other hand, the simulation indicates that the pharyngeal muscles must generate a greater force to propel higher viscosity boluses, and thus that patients with impairment of the muscles required to propel the bolus would do better with low-viscosity foods. Simulations based on VFG data from a patient with brainstem stroke validate this hypothesis. Mathematical modeling improves our understanding of dysphagia and can supplement clinical tests to improve patient care.
S-3-11-03
THE CLA-SYSTEM IN A TRAINING PROGRAMME FOR NEUROLOGICALLY IMPAIRED PATIENTS
C. Pistarini*, A. Contardi*, G. Bertotti*, F. Ferri*, G. Bettoni°
* Department of Neurorehabilitation, S. Maugeri Foundation, Montescano Medical Centre - Italy
｡?Department of Radiology, S. Maugefi Foundation, Montescano Medical Centre - Italy
Dysphagia is a frequent symptom in neurologically impaired patients.
The Computerized Laryngeal Analyzer (CLA) system has been described as an essential tool for assessing and correcting laryngeal function during swallowing for booth the physician and therapist in everyday practice. In this study we have used the CLA for the evaluation and treatment of swallowing disorders in 10 patients with cerebrovascular accident (CVA) and in 10 patients with cranial trauma. The goals of the treatment were: 1) to strengthen laryngeal musculature; 2) to improve laryngeal and swallow coordination; 3) to improve swallow efficiency reducing fatigue; 4) to increase the rate, rhythm and intensity of the spontaneous swallow reflex.
In this study, patients were evaluated as follows:
- Evaluation of swallowing function performed by a therapist before entering the programme;
- Computerized training with a therapist;
- Assessment of the swallowing ability;
- Six-month interval with no CLA training;
- New assessment of the swallowing ability;
We found that in all of the cases examined the use of CLA was practical and not time-consuming for both the patient and for the operator. The real-time display of the laryngeal activity facilitate the patient's comprehension of the tasks to be performed, thus enhancing the efficacy of the rehabilitation program.
S-3-11-05
REHABILITATION OF SWALLOWING DIFFICULTY THE BAYLOR EXPERIENCE
BARRY S. SMITH, M.D., CHIEF OF REHABILITATION SERVICES BAYLOR HEALTHCARE SYSTEMS DALLAS, TEXAS
PURPOSE: This presentation will describe the training program for patients at the Baylot Institute of Rehabilitation. This program uses a team approach in which both Speech Pathologists and Occupational therapists are trained in swallowing therapy and then treat or co-treat as indicated by the needs of the patient.
METHOD: Traditionally in the United States Speech Pathologists have been trained in swallowing therapy and have done all of the true swallowing therapy and the testing for dysphagia with the Radiologists. Initially at the Baylot Institute this role was given to the Occupational Therapists. In the large teaching hospital next door, Baylor Medical Center, this role was given to the Speech Pathologists. As these institutions began sharing patient training a program developed using the expertise of all the therapists.
RESULT: The combining of these disciplines with their unique approaches to swallowing disability led to a much improved patient care delivery especially in regards to the interwining of swallowing and feeding aspects of rehabilitative care. Additionally cost savings could be added at times when one therapist could combine the roles of both disciplines when indicated.
CONCLUSION: Swallowing therapy as a combined patient training effort by two rehabilitation disciplines is beneficial to patients with improved outcomes and can be cost effective as well.
