It is my distinct pleasure to return to Japan．In particular，it is an honor to once again address the Japanese Society of Dysphagia Rehabilitation．Much has happened in four years．In discussions I have had with your colleagues，it is clear to me that this Society has made great strides toward educating medical personnel，and dysphagic patients and their families about the diagnosis and treatment of the dysphagic condition．I would congratulate the planning committee for the selection of this years’ theme，“the right to eat”．Personally，I have made a philosophical，but I think medically relevant change in my own thinking about dysphagia treatment． Rather than emphasizing the need to prevent aspiration pneumonia，our focus should be on allowing patients to continue eating in the safest manner possible，The implication of this philosophical stance is that we must take very seriously the impact of taking away a patient's right to oral alimentation． In the United States，dysphagia services are paid for by insurance companies．The regulation of the policies for financial reirnbursement is monitored by the Health Care Financing Administration．This group has asked the American Speech，Language，and Hearing Association to provide outcome data on the benefit of our services with dysphagic patients．Unfortunately，there are few data on this subject．To gather the data we have to decide what to measure and how to measure it．What I will talk about today is our preliminary thinking on this topic．
As a basic study to develop the technique to take care of the elderly patients with the difficulty in swallowing，we investigated the effects of aging on the changes of respiration during swallowing. The subjects swallowed 10 ml of water of the room temperature and their respirograms and surface electromyograms （EMGs） of the suprahyoid muscles were simultaneously recorded. The subjects who understood the purpose of the present study and expressed their consent classified into the following three groups： young group （n＝20，mean age 19.5 ± 2.7 years）， presenile group （n＝10， mean age 64.8 ± 3.2 years） and senile group （n＝17， mean age 85.6 ± 2.9 years）. Their respiration patterns during swallowing were classified and the frequency of each pattern was calculated. Furthermore these three groups were compared with one another as to the frequency of respiration pattern， the resting respiratory cycle and the duration of deglutition apnea. EMGs of the suprahyoid muscle activity were also compared between the young group and the senile group. The respiration pattern was classified into two types， each of which comprised three subtypes： subsequent expiration type （eae， ae and iae subtypes） and subsequent inspiration type （eai， ai and iai subtypes）． Although the frequency of the eae subtype （expiration-apnea-expiration） was the highest in all the three groups， the result of the senile group （42.6％） was significantly lower than the results of the young group （60.5％）and the presenile group （64.3％） （P＜0.05）. The duration of respiration cycle was 4.39 ± 1.10 sec in the young group， 3.50 ± 0.63 sec in the presenile group and 2.95 ± 0.44 sec in the senile group. This indicated that the duration significantly decreased with the increase in age （P＜0.01）. The duration of deglutition apnea was 0.94 ±0.20 sec in the young group， 1.02 ± 0.20 sec in the presenile group and 1.36 ± 0.46 sec in the senile group. This indicated that the duration in the senile group significantly increased （P＜0.01）. Regarding the muscle activity，the interval between the muscle contraction starting point and the peak EMG point and the interval between the muscle contraction starting point and the apnea starting point showed the significant increase in the senile group （P＜0.01）. ln the young group， the peak EMG was achieved 0.04 ± 0.08 sec after the onset of apnea and the coincidence between the apnea starting point and the peak EMG was recognized. ln the senile group，the achievement of the peak EMG was significantly delayed and observed 0.26 ± 0.30 sec after the onset of apnea. Although the average result of electromyography and the integrated result significantly increased in the senile group， no remarkable difference in the peak EMG point was recognized between the two groups. These results suggested that the respiration pattern during swallowing and the duration of deglutition apnea changed with the increase in age.
We developed a scale to evaluate the swallowing function in the patients with disturbance of consciousness and studied its clinical usefulness．The subjects were 17 inpatients treated in this medical center． All these patients suffered from prolonged consciousness disorder due to severe traumatic brain injury and depended totally on tube feeding． The newly developed evaluation scale for prolonged disturbance of consciousness comprised the following five categories： 1) mode of feeding， 2) lip closing function， 3) chewing function， 4) swallowing function and 5) coughing and reflux of nutritional supplement． The degree of impairment was evaluated on a scale of one to four： severe (10 points), moderate (8 points)，mild (5 points) and extremely mild (0 point)． According to this evaluation scale， a patient with the severest impairment was given a maximum score of 50．The patients were classified by their total scores into the following four groups： severe group of a score range of over 40 (n＝0)， moderate group of a score range of from 30 to 39 (n＝5)， mild group of a score range of from 20 to 29 (n＝11) and extremely mild group of a score range of under 19 (n＝1)．Regarding category 1， all the patients were given the maximum score because they were placed on tube feeding． As for other categories， the degrees of impairment were rated as mild or extremely mild in more than half of the cases． These results suggested that we could separately employ effective treatment depending on the severity of each criterion． The newly developed evaluation scale seemed to be useful for introducing the swallowing training into the treatment for prolonged consciousness disorder．
During the period between August，1990 and March，1996，a total of 106 patients with recurrent pneumonia due to accidental swallowing underwent tracheoesophageal diversion developed by Lindeman in 1975．Their underlying diseases included cerebral palsy and nerve degeneration． Of these 106 patients， 31 were treated in the department of neurology， 73 in the department of pediatric neurology and two in the department of neurosurgery．The trachea was horizontally divided either between the second and third tracheal rings or between the third and fourth tracheal rings． The tracheal stump on the laryngeal side was united with esophagus by end-to-side anastomosis and the tracheal stump on the pulmonary side was treated by tracheostomy．The purposes of the present study included the evaluation of various patients according to several parameters， the selection of the patients with pneumonia due to accidental swallowing who could be best treated by tracheoesophageal diversion and the determination of the right timing of conducting this surgical procedure． Furthermore the conditions for the selection of the patients who were advised to undergo complete laryngectomy were discussed．After the surgical treatment， accidental swallowing disappeared and the incidence of pneumonia decreased in 80 of 85 cases． The respiratory function and the sleeping and awakening rhythm were improved in most of the cases， The percentages of the patients who were allowed to orally take all the food were 58% （14/24） in the department of neurology and 21%（13/61） in the department of pediatric neurology． Whether the oral intake is allowed or not depends on the individual neurological potency． After the operation， two patients started to utter voice and got into communication by using swallowing and eructation． The dominant postoperative complication was the ruptured suture at the site of trachea-to-esophagus anastomosis． Five of 18 ruptured suture patients underwent complete laryngectomy． These patients were characterized by high tension due to the postoperative difficulty in maintaining the rest of neck， enhancement of vomiting and cough reflex and elderly males with rigid tracheal cartilages．Since the clinical application of tracheoesophageal diversion， an increasing number of patients have undergone this surgical therapy because of the following reasons： reconstructible surgical treatment， patients’ and their family members’ high tolerance toward the surgical treatment which allows the preservation of larynx， the relative increase in the number of severely disabled infants because of the improvement of survival rate and the demand for the improvement of the quality of life of the patients suffering from chronic diseases (e.g. respiratory care at home)．The present study demonstrated that tracheoesophageal diversion was a reconstructible surgical procedure which induced few severe complications and that this surgical procedure more effectively prevented accidental swallowing than other surgical therapy． Consequently we regarded tracheoesophageal diversion as an excellent surgical treatment．