The Effects of Neuromuscular Electrical Stimulation on Swallowing Function in Healthy Older Adults

OBJECTIVE: To evaluate the effects of neuromuscular electrical stimulation on the swallowing function in healthy older adults without clinical dysphagia. METHOD: The subjects were 18 healthy older adults aged >70 years and 10 young adults aged <30 years without symptoms or a history of dysphagia. Both groups were evaluated by the functional dysphagia scale (FDS) and pharyngeal transit time (PTT), using a videofluoroscopic swallowing study with semisolid material. Only the healthy older adults group received neuromuscular electrical stimulation (NMES) on suprahyoid and infrahyoid muscles, 60 min/day, 5 days/wk, for 2 weeks. The healthy older adults group was then re-evaluated by FDS and PTT. RESULTS: The average PTT in young adults was lower than in healthy older adults. FDS of the oral phase was larger in the older adults than in the young adults. After NMES for 2 weeks in older adults, there was a significant improvement in the averages for PTT and FDS. CONCLUSION: The results of this study showed that healthy older adults without clinical dysphagia had decreased swallowing function when they were compared with young adults. After NMES, the swallowing function, evaluated by FDS and PTT, was improved in healthy older adults.

Swallowing Pattern according to Controlled Food Viscosity in Patients with Brain Lesion

OBJECTIVE: The response of the pharyngeal phase during swallowing is influenced by various factors including viscosity, shape, firmness, fracturability, and cohesive power. These factors affect the pharyngeal phase simultaneously, but little research has been conducted into their individual effects on the pharyngeal phase. This study investigated the relationship between controlled viscosity and pharyngeal transit time (PTT). METHOD: The subjects were 81 patients with naso-gastric tube due to brain dysfunction. PTT was assessed by video- esophageal fluoroscopy and the viscosity of the processed starch by Brookfield viscometer. High viscosity was defined as a controlled viscosity of 12% and 9%, medium viscosity as a controlled viscosity of 7.5%, 6%, and 4.5%, and low viscosity as a controlled viscosity of 3%, 1.5%, and 0% (liquid viscosity). RESULTS: PTT was prolonged with increasing viscosity in the experimental group. There were no significant differences between PTT of the experimental and control groups at any viscosity. Aspiration prevalence was 1.85%, 7.82%, and 22.22% in the high, medium, and low viscosity groups, respectively, and the three prevalences showed significant differences. CONCLUSION: PTT showed a tendency to be prolonged with increasing food viscosity in the experimental group.

The Effects of Viscosity on Oropharyngeal Phase

OBJECTIVE: The videofluoroscopic swallowing study (VFSS) has been accepted for standard method of dysphagia evaluations. But there is no research for oropharyngeal effects depending on the change of viscosity. METHOD: The 10 normal subjects without dysphagia symptom or history were participated. 4 test foods were selected according to viscosity which was measured by line spread test (LST); thick semiblended diet: LST 1 cm, Yoplait: LST 2.44 cm, tomato juice: LST 3.67 cm, 35% diluted barium: LST 4.15 cm. Each foods were swallowed 3 times during VFSS. We measured oral transit time (OTT), pharyngeal delay time (PDT), pharyngeal transit time (PTT), and cricopharyngeal opening time (CPOT) RESULTS: There was linear correlation between OTT and LST (cm)(r= 0.965, P<0.05). As the score of LST increased, PDT tended to increase linearly, but there was no statistical significance (r=0.949, P=0.509). PTT and CPOT had no significant correlation with viscosity. CONCLUSION: The viscosity affected OTT and PDT. The test foods of VFSS and dysphagia diet shoud be selected by viscosity measures.

The Effect of Neck Posture in Swallowing of Stroke Patients

Dysphagia is a disorder of the swallowing mechanism and presents a major problem in the rehabilitation of stroke patients. In-the present study, computerized laryngeal analyzer (CLA) was used for noninvasive assessment of the pharyngeal phase of the swallowing mechanism. Laryngeal elevation was measured with pressor sensor placed on the skin over the thyroid cartilage. In the study. CLA was applied at each posture of neck flexion, neutral, and extension in stroke group and control group. Significant differences were found in each of the these parameters measured in control group and stroke group. The quantitative measurements may aid the physician in choosing the appropriate therapy during the course of recovery. The onset latency of swallowing was delayed in stroke group than control group at all posture of neck(p0.05). The amplitude of swallowing was decreased in stroke group at extension and neutral posture of neck compared to those of control group (p0.05).