New findings of morphological and physiological investigations into neural control of swallowing and swallowing disorders are described.
In cats and humans, free nerve endings and taste buds were observed in the laryngeal epithelium, and beaded nerve terminals forming a network were found in the subepithelium. These findings suggest that free nerve endings easily respond to mechanical and chemical stimulation.
Based on physiological investigations, we propose the existence of highly sensitive mechanoreceptors known as“chemoreceptors”. It is thought that the structures and characteristics of these receptors are appropriate for elicitation of the protective reflex and the swallowing act.
Brainstem projections of the sensory fibers in the glossopharyngeal nerve and superior laryngeal nerve (SLN) were studied. The results suggest that the majority of sensory impulses from the pharyngolaryngeal region are carried into the interstitial subnucleus of the nucleus tractus solitarius (NTS) through the glossopharyngeal nerve and the SLN.
The movements of the pharynx and larynx during the second (pharyngeal) stage of reflexogenic swallowing are highly reproducible. This circumstance suggests that the movements are not a sequence of reflexes but are controlled by output from the central pattern generator (CPG) for swallowing. The location in the medulla oblongata and characteristics of the swallowing-related neurons (SRN), which receive orthodromic input from the SLN and burst during swallowing, were studied in the cat. The SRNs were classified into three types. Type I is a sensory-relay neuron which exists in the NTS and relays input from the SLN. Type II is an interneuron which exists in the parvocellular reticular formation and receives oligosynaptic input from the SLN. Type III is a motoneur-on which drives the swallowing-related muscles in the pharyngolaryngeal region.
Clarification of pathophysiology in patients with dysphagia is necessary for appropriate treatment. From the results of the clinical investigation, dysphagia caused by disorders of the central nervous system divided into dysphagia caused by lesion of the corticobulbar tract and dysphagia caused by lesion of the brainstem involving the CPG. Pathophysiology and treatment are different for each group.

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A case of speech and language disturbance from congenital mixed deafness with microtia and meatal atresia was reported. The subject was a 29-year-old male who entered our rehabilitation center due to heavy hearing loss. Mean hearing level was 81 dB in the right side, 84 dB in the left. The air-bone gap at 1000 Hz was 55 dB in the right side, 65 dB in the left. Examination of speech and language was attempted and yielded a deviation value of reading ability of 55 (equivalent to third year of junior high school) . Verbal IQ was 94, performance IQ was 103 and total IQ was 97 according to WAIS-R (Japanese Wechsler Adult Intelligence Scale-Revised) . In the articulation test, palataliza-tion was observed at velar stops, dental-alveolar fricatives, palatal alveolar fricatives, palatal fricatives and palatal alveolar affricates. The subject did not wish for operational treatment, his reasons being as follows : 1) His opinion is that if hearing loss were to be recovered, his pains and efforts in his life until now would have no significance. 2) To make external auditory meatus incurs risk of otorrhea after the operation. 3) He did not strongly wish to recover his hearing loss. 4) It was difficult to make him understand what his condition would be like if his hearing loss were recovered. These findings suggest that when selecting a treatment plan, we must recognize that problems of speech and language may persist even after hearing loss may be recovered by operation.

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To study the causes of speechlessness in autism, we selected 24 schoolaged autistic children from among our 143 patients, who have been receiving communication therapy for at least one year who participated in summer camps, and in whom ADL and other conditions were recognized.
(1) Absolutely speechless children comprised 24 % of our 143 autistic subjects: including spealcers capable of a few words, about 40 % of all our patients had difficulty communicating.
(2) All speechless children with autism are mentally retarded, but the severity of retardation differs from case to case.
(3) The speechless group may be devided in to two Subgroups : one with conspicuous mental retardation and the other with autistic tendencies.
(4) Suspected cases of macrocephaly, cerebral palsy, abnormal EEG, chromosome aberra-tion or phenylketonuria are included in 24 % of our patients.
(5) Three autistic children showed signs of apraxia of speech.
(6) Basic communication abilities were insufficient, such as recognizing their environ menta circumstances or manifesting their own intentions. Over half of the subjects showed evidence of self-inflicted injuries and assaults.

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In the present study, the articulatory movements of lateral articulation before and after speech therapy were investigated using ultrasonic tomography and dynamic palatography. The subjects included the four cases reported in the previous study and one additional case in which expiratory airflow is discharged from the left side ; the other four cases showed expiratory airflow from the right side.
Results were as follows. 1) Observation by ultrasonic tomography showed that first the tongue moves upward, after which the edge of the posterior portion of the tongue on the same side as the airflow moves rapidly downward during lateralized segments in stops and affricates. The same portion of the tongue moves slightly downward in fricatives and vowels. The movements of the tongue edge were symmetrical in normal articulation after speech therapy. 2) Observation by dynamic palatography showed that the tongue continues to contact with the hard palate during lateral articulation, while there was a space at the center of the oral cavity during normal articulation after speech therapy.
These results show that the edge of the posterior portion of the tongue on the side of expiratory airflow makes the main contribution to the production of the pathological speech sounds of lateral articulation. Since with lateral articulation the elevated tongue blocks the midline channel for expiratory airflow, production of speech sounds is thought to be accomplished by expiratory airflow between the buccal mucosa and dental arch.

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It is postulated that the rate, fluency and rhythm of speech may be closely related to mental factors. To examine the relevance between “mental tempo” as a mental factor and “speech error” as a condition of stuttering, 8 stutterers who are aware of their stuttering and 21 non-stutterers were asked to read a sentence and tap a finger of their dominant hand.
When tapping was performed under natural conditions, it was defined as “mental tempo”. When tapping was done under mental stress, it was defined as “mental tempo with conditions”. Stability was defined according to “fluctuations”, and the rate was measured. The following results were found.
(1) The rate of mental tempo changed with mental state in all subjects. However, it was difficult to detect any abnormal situation recognizable only in stutterers. To examine stability, fluctuations between “mental tempo” and “mental tempo with conditions” were compared. (2) In the stutterers, a change was recognized in 6 of 8 (75%) due to the in conditions, whereas in the non-stutterers a change was recognized in 4 of 21 (19%) due to the in conditions. Therefore, it was found that individual homeostasis might be low in the mental tempo of stutterers. (3) In 4 stutterers fluctuations in mental tempo varied broadly from the average of the non-stutterers and an abnormal condition was suggested. (4) When fluctuations in mental tempo were compared with speech error, no statistical correlation in the same group was recognized. However, from the scores of the 4 stut-terers, it was thought that fluctuations in “mental tempo” influence attitude to stuttering more closely than speech error.

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Articulatory function was perceptually investigated in 58 individuals with dysarthria using an intelligibility test involving 100 Japanese monosyllabics. Major results include the following.
1. Comparison of syllables called“yoon”and syllables called“chokuon”showed that the mean intelligibility score for“chokuon”was significantly higher than that for“yoon”in all severity groups and in all types of dysarthria.
2. Comparison of vowel syllables and consonant syllables showed that the mean intelligi-bility score for vowel syllables was higher than that for consonant syllables in all severity groups and in all types of dysarthria.
3. Among vowel syllables, the highest intelligibility score was for /a/ and the lowest for /i/and /e/, which are classified as front vowels in all severity groups. Analysis of vowel intelligibility according to type of dysarthria showed that scores for the five vowels of types with pathophysiological motor paralysis are different from those of types without motor paralysis.
4. A confusion matrix showed that /i/ was apt to be replaced by /e/, and /e/ tended to be substituted by /i/.
Based on these findings, a treatment strategy for articulatory dysfunction in dysarthric speakers was discussed.

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Articulatory function for consonants was perceptually investigated in 58 individuals with dysarthria using an intelligibility test involving 100 Japanese monosyllabics. Major results include the following.
1. With respect to manner of articulation, intelligibility scores were high for nasal and fricative categories, and low for plosive, affricate, and flapped categories in all severity groups and in all types of dysarthria.
2. With respect to place of articulation, there were no significant differences in intelligi-bility scores among the 6 place categories in nearly all severity groups and in all types of dysarthria.
3. Intelligibility scores for unvoiced sounds were higher than those for voiced sounds in almost all severity groups and in all types of dysarthria.
4. Phonemic analysis showed that there was a remarkable difference among phonemes, with intelligibility scores ranging from 30.08% to 68.39%.
Based on these findings, a treatment strategy for articulatory dysfunction in dysarthric speakers was discussed.

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This study was performed with the following two goals. First, a survey was conducted to determine common modes of treatment for varying degrees of sulcus vocalis. A questionnaire was sent to 34 clinicians in the United States, and 28 responses (82%) were obtained. From the survey, I learned that surgical intervention becomes more common as the severity of the condition increases. Of the various facilitating techniques recommended by Boone, place the voice and respiration technique are among the popular options. The pushing exercise was one of the least frequent adopted.
Second, to test the efficacy of voice therapy in the treatment of sulcus vocalis I carried out the following study. The subjects were 4 male patients diagnosed with bilateral moderate sulcus vocalis.
The perceptual quality of these patients' voices was primarily breathy and strained. Place the voice was the therapy technique used for this study.
Therapy was continued over 3 months. After therapy, the following results were obtatined :
1. Perception : breathiness and strained decreased with GRBAS rating.
2. Laryngeal findings : decreased prominence of false vocal cords, and improved glottal closure.
3. Acoustic evaluation : clearer formants and reduced noise components in post-therapy spectrogram.

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The purpose of injecting atelocollagen to treat Sulcus vocalis until now has been to achieve a better voice by restoring vocal fold vibration during phonation. When unilateral recurrent nerve paralysis is present, voice improvement is often achieved by repeated injections into the muscle layer of the vocal fold on the paralyzed side. However, in sulcus vocalis there is little collagen accumulation even when injected into the muscle layer, and the limits of treatment seem to be reached without any improvement in hoarse-ness. Because there is no motor paralysis of the vocal folds, this is suspected to be due to the collagen diffusing as a result of muscle contraction movements during phonation and deglutition. Moreover, even when injected submucosally, because the collagenmerely hardens, it remains in a white state after it is injected, but with little subjective voice improvement. However, noting that the white portion persists, when we tried injecting atelocollagen submucosally on the unaffected side, we encountered cases in which a very good voice lasted for a long time. In this article we report on the effects of atelocollagen injection in animal experiments and its indications for in the treatment of sulcus vocalis.

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Background : It is well known that surgical treatment for sulcus vocalis is extremely difficult ; however, intracodal injection is one method for creating new free edges of a vocal fold by augmentation. Here, we report in detail good results achieved using autogenous fat as the injection material. We also discuss an additional approach for treating the sulcus itself.
Method : Two subjects with sulcus vocalis were treated with intracordal injections of autogenous fat harvested by suction from the abdominal wall. Voice production was evaluated prior to injection and at intervals after injection.
Results : Voice improved not only subjectively but also objectively.
Discussion : A major disadvantage of this method is that lasting effectiveness is rather limited due to the absorption of fat after injection, so transplantation also should be considered. Moreover, a potential direct approach for treating the sulcus itself includes resectioning of the sulcus and medicating with Tranilast, which our experimental findings showed contribute to further voice improvement.
Conclusions : Although we attained moderate improvement of phonation by autogenous fat injection, we conclude that resectioning of the sulcus and use of Tranilast as a direct approach for treating the sulcus itself might contribute to greater voice improvement.

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Thyroplasty type I+III is a laryngeal framework surgery, in which the thyroid cartilage is longitudinally incised in the anterior third of the thyroid ala and the cut posterior end is inserted into the inside of the anterior end of the cartilage. The vocal fold is medially compressed and stiffness of the vocal fold is reduced. This surgery was performed on three patients with salcus vocalis. All patients had severe hoarseness before surgery but showed some improvements of voice after surgery. Objectively, however, the voice was still hoarse and glottal incompetence remained.
To reduce the rigidity of the sulcus and enhance surgical effectiveness, we devised a pediculated dermis transplantation into the vocal fold with adaptation of the thyroplastic technique. In excised human larynges, large fenestration on the thyroid ala was shown to facilitate exposure of the vocal process of the arytenoid cartilage beneath the vocal ligament, and to enables the surgeon to fix the transplanted tissue on the arytenoid cartilage.

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