Keynote Lecture by Eiichi Saitoh, Japan
Dysphagia rehabilitation is a relatively new but rapidly growing area in physical and rehabilitation medicine. For example, Krusen's Handbook of Physical Medicine and Rehabilitation, it was a textbook so called bible of rehabilitation medicine, did not have a chapter of swallowing until the version 4th (1991). In Japan, with the major contribution of physiatrists, Japanese Society of Dysphagia Rehabilitation (JSDR) was established in 1995 with 500 members, and its membership rapidly increases to 13,500 in 2017. In the latest annual meetings of Japanese Association of Rehabilitation Medicine, dysphagia related presentations accounted for about 6~8%. The growing tendency in this field reflects rapidly graying society in Japan.
Here I will touch on three topics in dysphagia management.
1) Eating is very common activity in life. And physiologically there is a large difference between eating and drinking in human being. However, until recent years, we didn't know its physiological mechanism despite we have known drinking mechanism very well for long period. Actual eating mechanism of human was discovered and explained by the Process model (Professor Palmer JB, Johns Hopkins University). We added the clinical significance to it by doing the experiment of two-phase food eating. This experiment clearly showed bolus propulsion into hypopharynx during chewing before start to swallow. Now we know more clearly about the suitable bolus property easy to drink and eat using this model.
2) Videofluoroscopic and videoendoscopic examinations are used commonly now as diagnostic and treatment-oriented assessment tools. They were implemented in clinical setting during these 30 years. Dysphagia management is a process of PDCA cycle. In this cycle, C (check) is a key for success of management. We will talk about the mean of treatment-oriented assessment as "knowledge of result" and " knowledge of performance" for effective motor learning in exercise.
3) Recently we introduced an innovative methodology using CT for revealing swallowing dynamics. The 320-row area detector CT (320-ADCT) is a quite strong tool for revealing swallowing kinematics. It has excellent spatial resolution (0.5 mm voxel) and adequate time resolution (10 frames/s) providing superb dynamic 3D images of swallowing. The importance of swallowing CT is summarized in two points; 3D imaging and quantitative measures. These include event timing, kinematic analysis of tongue, hyoid, and laryngeal motion, and volumetric analysis of the pharynx. In this talk, we will show beautiful pictures or movies of swallowing you have never seen before.