The subjects studied were 10 patients who were diagnosed with lateral medullary infarction according to the results of magnetic resonance imaging (MRI). They consisted of seven males and three females and their mean age was 58.3 years． Dysphagic symptoms were severe in four patients and mild in four patients． The remaining two patients showed no dysphagic symptoms． Two patients who needed tube feeding were discharged from this hospital． The patient who showed the most severe symptoms was placed on conservative therapy for four months after the onset of this disease． Fortunately the conservative therapy was effective for the improvement of symptoms and oral feeding was initiated． Except for dysphagia， no difficulties were recognized in the activity of daily living in all the cases except for dysphagia． MRI revealed the lesion in the medial part of the lateral portion of medulla oblongata in four cases of severe dysphagia， Regarding the etiology of lateral medullary infarction， thrombosis was recognized in six cases and the dissection of vertebral artery (VA) in four cases． The latter patient group were younger and at lower risk of cerebral infarction than the former patient group． Three of four patients with severe dysphagia suffered from VA dissection． VA dissection， which was regarded as the causative factor in about half of the cases of lateral medullary infarction， was recognized in most of the patients with severe dysphagia． The movement of head and neck should be carefully controlled in the cases of VA dissection． lt is of prime importance to identify the etiology of lateral medullary infarction and to establish the adequate treatment strategy at its early stage．
It is a well-known fact that food texture is affected by various factors such as compression methods，forms of plungers and clearance．The effects of compression speed on food texture，however，have not been sufficiently clarified．ln this situation，we adjusted the compression speed to the maximum and minimum levels to study the changes of food crushing property．Five types of food were used in the present experiments．Statistically significant differences in measurement values were recognized in all five types of food for the rupture stress．These differences were revealed in two of the five types of food concerning rupture strain and in one of them for the initial modulus．These results demonstrated that the compressiom speed remarkably affected the physical property levels of food．The speed of human masticatory movement is approximately ten times faster than that of the measurement equipment used in these experiments．Therefore，the physical state of food reported in this study might be significantly different from that in the human during their masticatory movement．The present study pointed out the necessity to establish a new simulated measurement system of human masticatory movement and the classification of food so that the relationship between human masticatory movement and the physical state of food might be correctly evaluated．
Videofluorography（VF）has been used often in recent years as a technique to evaluate the feeding/swallowing function．Only a few researchers，however，have used the results of VF to perform a dynamic study of feeding and swallowing movement and to evaluate the progress of feeding and swallowing rehabilitation．In the present study，we used video tape recorded from VF for three post-operative oral/pharyngeal cancer patients to dynamically represent the movement as time-series reconstructed images in order to objectively evaluate feeding functions．Using the video tape obtained from the patients，the movement of the tongue and epiglottis during swallowing was extracted as reconstructed images and the results were evaluated through the time-series visual analysis system．In order to observe the dynamics of each movement more clearly， we shifted the traced time-series reconstructed images of the tongue and epiglottis movement by 37 and 8 degrees respectively．This technique enabled us to compare the level of feeding and swallowing functions to evaluate the improvement of the tongue and epiglottis movement quantitatively and qualitatively．This analysis system which reconstructs the video through the time-series technique can be thought of as an effective method to compare each movement first and second the feeding and swallowing rehabilitation，and objectively and dynamically evaluate the movement of each particular section． Furthermore this time-series reconstructed analysis system seems to contribute significantly to the observation and evaluation of the changes of the soft tissues due to feeding and swallowing movement．
A new type of rice gruel was developed for dysphagic patients．ln order to evaluate the impression and texture，a questionnaire was conducted． Thirty-eight healthy young volunteers were registered as the participants in the first questionnairing．Of these 35 participated in the second questionnairing．Six dysphagic patients were selected as the subjects of the present study and submitted their replies to some of the questions． The data obtained from those who tasted the newly developed rice gruel were compared with the data obtained from those who tasted two types of conventional Japanese rice gruel； zengayu (polished rice content 20％) and gobugayu (polished rice content 10％). The texture of the three types of rice gruel was measured at 20℃．The hardness of the newly developed rice gruel ［(0.30±0.01)×103N/m2］ was significantly lower than that of the two types of conventional Japanese rice gruel ［zengayu (6.62±0.32)×103N/m2；gobugayu (0.44±0.02)× 103N/m2］．The adhesiveness of the newly developed rice gruel ［(1.55±0.15)×10J/m3］was significantly lower than that of the two types of conventional Japanese rice gruel ［zengayu (104.08 ±3.73)×10J/m3； gobugayu (7.53±0.49)×10J/m3］．Cohesiveness of the newly developed rice gruel (0.52± 0.02) was significantly lower than that of zengayu （0.62 ±0.01） and significantly higher than that of gobugayu (0.30 ±0.04). The temperature of rice gruel was adjusted to 55℃ so that its texture could be accurately evaluated at the temperature when it was usually ingested．The results obtained in this experiment were similar to those obtained in the experiment carried out at 20℃ except for the significant difference in cohesiveness between the newly developed rice gruel and zengayu． According to the replies obtained from the healthy young volunteers， there were no differences in swallowability and residual sensation in the mouth between the newly developed rice gruel and gobugayu． However，they reported that the newly deveioped rice gruel was inferior to gobugayu in visual， tactile and gustatory aspects and that the new gruel was superior to zengayu in tactile aspect including the feeling in the throat， palatability，swallowability and residual sensation in the mouth． The dysphagic patients reported that the new rice gruel was superior to the two types of Japanese conventional rice gruel in swallowability and the residual sensation in the mouth．The results obtained in this questionnairing suggested the higher swallowability of the newly developed rice gruel.