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Objective Spasmodic dysphonia (SD) is a complex neurological communication disorder characterized by a choked, strain-strangled vocal quality with voice stoppages in phonation. Its symptoms are exacerbated by situations where communication failures are anticipated, and reduced when talking with animals or small children. Symptoms are also reduced following selected forms of treatment. It is reasonable to assume that surgical alteration reducing symptoms would also alter brain activity, though demonstration of such a phenomenon has not been documented. The objective of this study is to reveal brain activity of SD patients before and after surgical treatment. Methods We performed lateralization thyroplasties on three adductor SD patients and compared pre- and post-operative positron emission tomography recordings made during vocalization. Results Pre-operatively, cordal supplementary motor area (SMA), bilateral auditory association areas, and thalamus were activated while reading aloud. Such activity was not observed in normal subjects. Type II thyroplasty was performed according to Isshiki's method and the strained voice was significantly reduced or eliminated in all three patients. Post-operative PET showed normal brain activation pattern with a significant decrease in cordal SMA, bilateral auditory association areas and thalamus, and a significant increase in rostral SMA compared with pre-operative recordings. Conclusion This is the first report showing that treatment to a peripheral organ, which reverses voice symptoms, also reverses dysfunctional patterns of the central nervous system in patients with SD.

Immunoglobulin A1 (IgA1) concentration in the plasma of patients with IgA nephropathy (IgAN) as the cause of renal failure is higher than that in the plasma of normal controls. IgA1 with abnormal sugars is considered to deposit in the glomerular mesangium, aggravating nephritis in IgAN. Jacalin is a lectin that recognizes sugars on IgA1. However, its selective-recognition for normal-type (ST type, NeuAc-α(2,3)-Gal-β(1,3)-GalNAc) and abnormal-type (T type, Gal-β(1,3)-GalNAc; Tn type, GalNAc; STn type, NeuAc-α(2,6)-GalNAc) sugars α-O-linked to serine/threonine in IgA1 is weak. Therefore, jacalin cannot be used for recognizing specific sugar types on IgA1. We attempted to develop a new recognition method for specific sugar types on IgA1 by utilizing the multirecognition capability of jacalin. Its binding abilities were regulated by heat denaturation with suitable template sugar (galactose or N-acetylgalactosamine). Further, we successfully prepared denatured-jacalin derivatives, which recognized ST-/T-type sugars on IgA1, by sugar-immobilized affinity chromatography. Enzyme-linked immunosorbent assay of denatured-jacalin derivatives, showed the ratios of abnormal sugars on IgA1 in the plasma of IgAN patients and normal controls to be approximately 60% and 20%, respectively. The results proved that profiling of sugar types in IgAN can successfully be performed by solely using jacalin derivatives.

Aneurysms of the superficial temporal artery are infrequent, and most of them are traumatic aneurysms located on the superior temporal line. We present a rare case of preauricular aneurysm of the superficial temporal artery. The patient was an 81-year-old woman who had a pulsating mass in the preauricular lesion. It was successfully removed by surgery. Histopathologically, it was suggested to be an aneurysm of the superficial temporal artery caused by atypical arteritis. She has not had active inflammatory findings, but follow-up is needed.

Since 1990, we have performed steroid injection into the vocal fold by fiberoptic laryngeal surgery (FLS) under local anesthesia. In this study, the usefulness of this method was evaluated in 28 patients with vocal nodules. Under monitoring using a fiberoptic laryngoscope, a curved injection needle was inserted via the oral cavity and steroid was injected. Endoscopic findings showed that the vocal nodule had disappeared in 17 patients of the 27 patients and decreased in 10 after injection. The maximum phonation time was 10.9 s before operation and 13.9 s after operation, showing a significant increase (P

The aim of this study was to regenerate the injured vocal fold by means of selective cultured autologous mesenchymal stem cells (MSCs). Eight adult beagle dogs were used for this experiment. Selective incubation of MSCs from bone marrow was done. These MSCs were submitted to 3-dimensional incubation in 1% hydrochloric acid atelocollagen. Three-dimensional incubated MSCs were injected into the left vocal fold, and atelocollagen only was injected into the right vocal fold of the same dog as a control. Four days after injection, the posterior parts of the vocal folds were incised. The regeneration of the vocal fold was estimated by morphological and histologic evaluations. Our results showed that 3-dimensional incubated MSCs were useful in the regeneration of the injured vocal fold. This study shows that damaged tissues such as an injured vocal fold would be able to be regenerated by tissue engineering.

The recurrent laryngeal nerve (RLN) does not regenerate well after it has been cut, and no current surgical methods achieve functional regeneration. Here, we evaluate the functional regeneration of the RLN after reconstruction using a biodegradable nerve conduit or an autologous nerve graft. The nerve conduit was made of a polyglycolic acid (PGA) tube coated with collagen. A 10-mm gap in the resected nerve was bridged by a PGA tube in 6 adult beagle dogs (group 1) and by an autologous nerve graft in 3 dogs (group 2). Fiberscopic observation revealed functional regeneration of the RLN in 4 of the 6 dogs in group 1. No regeneration of the RLN was observed in any dog in group 2. We also tested for axonal transport, and measured the compound muscle action potential. The RLN can be functionally regenerated with a PGA tube, which may act as a scaffold for the growth of regenerating axons.

We examined cortical activation by speech in patients with moderate inner ear hearing loss using PET to investigate the response of the language network to insufficient speech input. We made two word lists, well-perceived words and poorly-perceived words, and measured rCBF during monaural presentation of these words. Well-perceived words activated bilateral temporal lobes, bilateral inferior frontal gyri (IFG) and left angular gyrus (AG) regardless of the ear stimulated, Poorly-perceived words activated contralateral temporal lobe and bilateral IFG, while little or no activation was observed in the ipsilateral temporal lobe and left AG. Insufficient activation of the temporal lobe ipsilateral to the ear stimulated might correlated with less accurate word comprehension in patients with inner ear hearing loss.

Thirty patients with primary hyperparathyroidism (PHPT), who were all surgically treated with a parathyroidectomy, were retrospectively studied. Ultrasonography was the most useful preoperative imaging. Pathological findings revealed 28 adenomas, 1 hyperplasia, and 1 carcinoma. In all cases, only one swollen gland was removed, and values of serum calcium and parathyroid hormone were normalized after surgical treatment. There were no significant postoperative problems. The suggested treatment for PHPT is the extirpation of one swollen gland, which is detected with preoperative imagings.

Automotive parts produced using a powder metallurgy (P/M) process are commonly used in automobiles because they can be produced without the use of machining and with a special alloy design. This paper describes how the P/M process can be applied to the production of environmentally friendly automotive parts. The paper begins with a discussion on how the utilization of P/M for net-shape manufacturing makes it possible to conserve both energy and materials due to the fact that machining is unnecessary. Evidence is then presented that shows that it is possible to produce warm-compacted automotive P/M parts with sufficient strength even without the use of special alloy elements and/or heat treatments. As a final example, magnet materials made using spark-plasma sintering are described. This spark-plasma sintering process makes it possible to create high-performance magnet parts that are highly energy efficient. Finally, taking into consideration the above-mentioned example, the ideal P/M process is discussed from an environmentally benign point of view.

頸部食道の陳旧性腔外魚骨異物例を報告した。症例は32歳の女性で5カ月前にカレイを摂食したことによる異物であった。他院にての食道鏡検査上，異物は発見されず，1カ月後のCT検査結果から異物の残存が指摘された。症状が軽微であったため放置していたが，誤飲から5カ月後，摘出を希望して来院。頸部外切開にて頸部食道筋層内に埋没する異物を粘膜損傷なく摘出し得た。頸部食道の陳旧性腔外異物例は渉猟し得た限り，国内2例目であった。

Congenital piriform sinus fistula, which is usually unilateral, is recognized as a cause of acute suppurative thyroiditis. We have encountered a rare case of bilateral piriform sinus fistulae. The patient, a 53-year-old female, was referred to our hospital because of right neck swelling, which improved after conservative treat. Three months later, an abscess of the left thyroid lobe was presented and was improved after incision and drainage. The diagnosis of bilateral piriform sinus fistulae was made by hypopharyngeal enhancement radiography. Total fistulectomies were performed. There was no recurrence observed six months after surgery.

We designed a new type of nonlinear digital hearing aid (TD-1) with near-instantaneous amplitude compression for sensorineural hearing-impaired people. The amplification method utilized by the TD-1 normalizes the signal waveforms within a time window bounded by two adjacent positive going zero-crossing points. The signals within this window are amplified so that the maximum amplitude reaches a preset value, thus allowing a consistent peak amplitude to be maintained. To test this, we examined the efficacy of the TD-1 device in 31 patients with sensorineural hearing loss. When tested for recognition of Japanese sentences in a quiet environment, 7 of 25 (28.0%) subjects wearing the TD-1 showed a 20% or greater increase in the maximum intelligibility score than that obtained when wearing their own linear hearing aids. In addition, 7 of 31 (22.6%) subjects showed the same increase with the TD-1 relative to that obtained when they wore HA70 or HA73 devices (Rion Co., Ltd., Tokyo, Japan), which are conventional analogue hearing aids. These results indicate that TD-1 can be effective for patients with sensorineural hearing loss.

京都大学耳鼻咽喉科で過去4年間に手術を行った甲状腺腫瘍228例のうち,術前の穿刺吸引細胞診でクラスIII（境界病変）の診断を得ていた37例を対象に，術前所見と良悪性との関連について検討した。37例中悪性であったものは17例（46％）と約半数を占めていた。さらに術前の病歴，触診，画像所見から手術除外例を予測し得ないか検討した結果，触診上軟らかく石灰化がない症例，境界明瞭で軟らかい症例では14例中13例が良性とほとんどが良性であったが，濾胞癌の1例を含んでいた。悪性例が半数を占めていたこと，良性の可能性が高い例は見いだせるものの濾胞癌の可能性は否定できないことより，クラスIIIであれば手術適応とするのが妥当と思われた。

Since the introduction of warm compaction in 1994, several new warm-compacted powder metallurgy (P/M) parts have been developed. However, the main applications to date have been limited to machine tool parts and parts for agricultural tools, for example. Only a few automotive parts have been developed by using the warm-compaction method. Engine parts have not yet to be developed, particullary. Here, we investigate the mechanical properties and wear resistance of warm-compacted P/M materials, and the developed warm-compacted P/M engine sprockets. A method of controlling the powder temperature is also described.

In 289 benign thyroid tumor operations performed at our hospital between 1988 and 1999, we treated 8 patients with mediastinal goiter, 4 of which were adenomas and 4 were adenomatous golters.It was possible to remove the goiter entirely via acervical approach in all 8 patients and even goiters extending to the aortic arch were safely removed without requiring sternotomy. There were no complications such as recurrent nerve palsy or postoperative hemorrage in those patients.The surgical approach, operative technique and results of therapy are discussed and transcervical approach for resection is emphasized.

Background: it is believed that the number of neurons of the human cortex increases rapidly in the first postnatal year, and then decreases gradually towards adult level as their functions are revised up to 11 years of age (‘synaptic revision’). It is also confirmed that regional cerebral blood flow (rCBF) at rest represents the density of the neurons and decreases in accordance with the synaptic revision in process. If synaptic revision does not occur, rCBF remains at high level. Thus, we can evaluate whether functional differentiation has occurred in the human cortex by measuring rCBF at resting state. Objective: to examine functional differentiation of the auditory association area (A2) in prelingually deaf subjects. Methods: six postlingually and six prelingually deaf subjects who had undergone cochlear implant (CI) were involved in the current study. All prelingually deaf subjects underwent CI over 8 years old. The rCBF in A2 was examined during resting and listening to speech sounds using positron emission tomography (PET) and H 2 15 O intravenous injection. Twelve normal subjects’ rCBFs were also measured as control. Furthermore, three prelingually deaf subjects underwent follow up PET studies in which cortical activities in A2 for listening and lipreading were examined. Results: in the examination of rCBF at rest, rCBFs of prelingually deaf subjects in A2 showed significantly higher than those of either the postlingually deaf subjects or normal subjects. During listening, rCBFs in A2 increased in postlingually deaf subjects and normal subjects, while there was no significant rCBF increase in the prelingually deaf. High rCBF level in A2 at rest observed in prelingually deaf subjects implied a lack of synaptic revision, and it was suggested that the functional differentiation for auditory processing was little in the A2 of prelingually deaf subjects. In the follow up study for three prelingually deaf subjects, activation of A2 was observed during lipreading but not during listening in two cases, who had developed the skill of lipreading while speech recognition was not improved by CI. In contrast, the other case had not used any visual clues in daily communication prior to CI, and the hearing acuity was well improved by CI. This case demonstrated an activity in A2 during listening, while lipreading induced no activation. Conclusion: it is suggested that functional differentiation of A2 should differ according to which of visual and auditory clue is chiefly used during critical periods for speech acquisition. The findings are thought to be important for us to schedule the education and treatment for prelingually deaf children.

We report a patient with a ranula extending into the parapharyngeal space. A 21-year-old male visited our clinic with complaints of right submandibular swelling for three months. Several tests including MRI were performed that led to the diagnosis of the ranula. Resection of the right sublingual gland was performed, which satisfactorily treated the cyst. We think the best treatment of a ranula is to resect the sublingual gland.

We report two cases of chronic thyroiditis that caused dyspnea due to tracheal stenosis. The first patient was a 50-year-old male and the other was a 45-year-old female. Both patients complained of dyspnea. A CT scan demonstrated a diffuse large goiter and tracheal stenosis. They both had caught a common cold, and after that they complained of dyspnea. We performed a total thyroidectomy in the first patient, and a subtotal thyroidectomy in the second one. After the operation, in both cases, the tracheal compression and dyspnea disappeared. A thyroidectomy is useful for dyspnea that is due to tracheal stenosis and caused by chronic thyroiditis.

A newborn male baby was referred to our clinic with upper airway obstruction caused by a huge mass in the mesopharynx. A CT scan revealed a huge tumor existing from the left parapharyngeal space to just under the skullbase. No communication with the inside of the skullbase was detected. The tumor was determined to be heterotopic brain tissue of the parapharyngeal space and was partially excised. Since the infant was asymptomatic with normal breathing and feeding, follow up is planned in the future.

Objective To ascertain effects of medialization thyroplasty on vocal fold vibration in glottic incompetence dysphonia. Study Design Quantitative videostroboscopic glottic measurements and vocal function study were perioperatively undertaken in 20 patients undergoing Isshiki's thyroplasty type I. Methods In digitized images, the glottal area, glottal width, posterior glottal width, and amplitude over an entire glottal cycle were measured and normalized by membranous vocal fold length. The ratio of closed phase to total phase of vibratory cycle was calculated from the data of the glottal area and the glottal width at the middle point of the membranous vocal fold. Well-accepted acoustic, aerodynamic, and perceptual measures analyzed vocal function. Results Glottal area and glottal width were reduced after surgery. While preoperative closure of glottal area was incomplete in all 20 patients, incomplete closure was obtained in 16 patients after surgery. In these 16 patients, closure of glottal width at the middle point of the membranous vocal fold was complete, whereas a posterior glottal gap remained in 14 patients. Closed phase over one cycle of glottal width waveform and amplitude of vocal fold vibration were increased after surgery. Glottal area, glottal width, posterior glottal width, and closed phase over one cycle of glottal width waveform correlated with vocal function measures. Conclusions Thyroplasty type I reduces a glottal gap and increases closed phase over one cycle and amplitude of vocal fold vibration, although a posterior glottal gap remains. With the improved glottic vibration, thyroplasty type I provides more efficient phonation in patients with glottic incompetence dysphonia.

高齢群と対照群の人工内耳装用者について術後の語音弁別成績と文章了解度, 質問紙法による主観的評価を検討し, 高齢者の人工内耳装用効果を評価した。 その結果, 術後高齢者の母音, 子音弁別成績は有意に改善し, 更にその経時的推移と文章了解度においても高齢群は対照群と差がなかった。 また, 主観的評価では人工内耳単独使用時に高齢群と対照群に一部の項目で有意差を認めた。 しかし, 総合的に見ると高齢者においても人工内耳の有用性が確認された。

The purpose of the present study was to examine vibratory patterns of the neoglottis and to ascertain the neoglottic conditions that could cause failure in tracheoesophageal shunt phonation. We studied 30 tracheoesophageal shunt speakers while using "trap-door" type voice prostheses. Videostroboscopy was undertaken to investigate vibratory patterns of the neoglottis during phonation of the sustained vowel sound /e/ in these patients. The voice qualities of the patients were judged perceptually. A regular neoglottic vibration was observed in 21 patients. Nine patients had irregular neoglottic vibrations. In this latter group, two patients had incomplete neoglottic closures with breathy voices, four patients had multiple contacts of several mucosal walls with rough voices, and three patients had tight neoglottic closures with strained voices. During stroboscopic evaluation of tracheoesophageal shunt phonation, regularity of the neoglottic vibration may be the most significant finding. These findings show that it is as important to evaluate neoglottic vibration in alaryngeal voicing as it is to study glottic vibration in laryngeal voicing. Stroboscopic examination may be a help to elucidate a cause of failure in cases of poor tracheoesophageal shunt speech.

To attain posterior medialization by thyroplasty type I, we simulated the surgery using 3 cadaveric larynges. Two approaches were applied to adduct the arytenoid cartilage: one involved compression of the vocal process, and the other, compression of the muscular process inward. The inner perichondrium was incised to reach the arytenoid cartilage from the framework. To compress the vocal process, a large silicone plug was required. In this method, there was some difficulty in compressing the vocal process precisely, and there was the risk of postoperative extrusion of the large plug. In contrast, the muscular process was more superficial relative to the framework, and it could be precisely compressed, resulting in sufficient posterior glottal closure. The silicone plug required for this procedure has a shallow depth that may provide the advantage of preventing postoperative extrusion. In conclusion, the compression of the muscular process is preferable for safely achieving posterior glottal closure.

We consider PET (positron emission tomography) measurement with SPM (Statistical Parametric Mapping) analysis to be one of the most useful methods to identify activated areas of the brain involved in language processing. SPM is an effective analytical method that detects markedly activated areas over the whole brain. However, with the conventional presentations of these functional brain images, such as horizontal slices, three directional projection, or brain surface coloring, makes understanding and interpreting the positional relationships among various brain areas difficult. Therefore, we developed three-dimensionally reconstructed images from these functional brain images to improve the interpretation. The subjects were 12 normal volunteers. The following three types of images were constructed: 1) routine images by SPM, 2) three-dimensional static images, and 3) three-dimensional dynamic images, after PET images were analyzed by SPM during daily dialog listening. The creation of images of both the three-dimensional static and dynamic types employed the volume rendering method by VTK (The Visualization Toolkit). Since the functional brain images did not include original brain images, we synthesized SPM and MRI brain images by self-made C++ programs. The three-dimensional dynamic images were made by sequencing static images with available software. Images of both the three-dimensional static and dynamic types were processed by a personal computer system. Our newly created images showed clearer positional relationships among activated brain areas compared to the conventional method. To date, functional brain images have been employed in fields such as neurology or neurosurgery, however, these images may be useful even in the field of otorhinolaryngology, to assess hearing and speech. Exact three-dimensional images based on functional brain images are important for exact and intuitive interpretation, and may lead to new developments in brain science. Currently, the surface model is the most common method of three-dimensional display. However, the volume rendering method may be more effective for imaging regions such as the brain.

The purpose of this investigation was to examine how speech intelligibility is affected by an impact noise for listeners wearing a hearing aid. In this experiment, the subjects consisted of 10 sensorineural hearing-impaired and five normal hearing listeners. Sentences mixed with a single impact noise or without noise were presented randomly to subjects wearing a hearing aid. The hearing aids used in this experiment were digital hearing aids (TD-1) which compress the signals in the time domain, and conventional analog hearing aids with peak clipping (PC) or automatic gain control (AGC). The results demonstrated that the intelligibility of sentences mixed with an impact noise decreased when the hearing-impaired subjects wore the analog hearing aid. Interestingly, the decline in intelligibility arose in the phrases not only after the impact noise, but also before the noise. On the other hand, there was none or only a slight decrease in intelligibility, regardless of the impact noise, in the normal hearing subjects and the hearing-impaired wearing TD-1. These results indicate that the compression method adopted by TD-1 is useful for patients with sensorineural hearing loss even under conditions with impact noises. We believe that incompletely suppressed impact noises mask the speech signal, and thus causes a decrease in the speech recognition of hearing-impaired subjects wearing analog hearing aids.

Three cases of laryngotracheal stenosis were treated by a staged operation called the `trough method' in our hospital. After removing the stenotic tissues in the inner space, a trough was created. A composite auricular cartilaginous graft with overlying skin was used for the closure of the trough. First, the graft was embedded beneath the skin near the trough, with the skin graft facing the inner space of the trough. About 2 weeks later, the embedded grafts were slid over the trough. Using this procedure, the trough was closed and a firm framework could be reformed. This method has an advantage for the survival of the graft, and makes framework reconstruction safely.

A rare case of nasolacrimal duct carcinoma is reported. A 64 year-old man visited our hospital complaining of left lacrimation and a mass in his left medial canthus. CT and MRI showed a solid heterogenous mass lesion in the nasolacrimal duct which was projected into the orbita and maxillary sinuses. Part of maxillary sinus not occupied by the lesion was filled with effusion. A preoperative cytological study using fine needle aspiration revealed a class V carcinoma, and the mass was suspected to be an adenocarcinoma. The mass was removed surgically and the bulb of the eye was preserved. A histological examination revealed a squamous cell carcinoma. Radiation therapy was performed postoperatively with a dosage of 50 Gy. The patient has been free of tumor for 24 months after the surgery.

Hemangiomas often occur in the head and neck region, and when they are removed surgically, postoperative functional deficit may appear.KTP laser is easily absorbed into the hemoglobin and makes it possible to perform photocoagulation for hemangiomas. We treated 8 patients of hemangiomas in the oral cavity, the pharynx and the larynx using KTP laser. Laser surgery could be easily performed in all cases without hemorrhage, and postoperative complication such as edema was not observed. Two cases demonstrated recurrence of tumor after operation, and were well controlled by repeated KTP laser surgery_??_KTP laser is a first choice for treatment of hemangiomas, because the surgery can be done easily in safe and repeatedly with good results.

A new operative technique for the treatment of floppy epiglottis is introduced in this report. Though its diagnosis is not so difficult by close observations using a flexible fiberscope, it is likely to be treated as an asthma attack or a paradoxical vocal cord movement. In previous reports of upper airway obstruction caused by adult floppy epiglottis: epiglottis prolapse during inspiration, the cause of this condition has been divided broadly into two categories: idiopathic cases and secondary cases. Partial or total epiglottectomy has been usually reported for the treatment of the relief of airway obstruction caused by a floppy epiglottis. It is very difficult to decide adequately how much volume of epiglottis to cut without postoperative sequelae. A V-shaped partial epiglottidectomy is described for its treatment. This technique is very easy, simple, and effective.

Paragangliomas often occur in the head and neck region and the carotid body is the most common site. However, a catecholaminesecreting carotid body tumor is rare, and dopamine-secreting tumors are especially unusual. In treatment of the tumor, the intraoperative control of hypertension is important. In this article, we report one case of a dopaminesecreting carotid body tumor that was operated on successfully under good control of blood pressure.

A rare case of a papillary carcinoma without a cyst arising from the thyroglossal duct remnant is reported. A 70 year-old woman visited our hospital complaining of a mass in the anterior midline of her neck. CT, ultrasonography and MRI showed a solid mass lesion over the hyoid bone, and a nor-mal thyroid gland. Fine needle aspiration biopsy of the mass yielded papillary carcinoma cells. The mass was removed surgically by Sistrunk's procedure, and a histological examination revealed a papillary carcinoma with a small part of normal thyroid tissue. The serum thyrogloblin levels, which had been 172ng/ml, were reduced to 5.4ng/ml after the surgery.

Speech discrimination and hearing aid performance in patients with hearing loss have been evaluated by speech audiometry where a tape or CD is utilized as a sound source. Since all sound samples in a list on the tape or CD are consecutively presented to the examinee, this conventional method provides the perception rate of the whole list. It has been difficult however, to evaluate the perception of a specific sound in the list.We developed a new method of interactive speech audiometry. Using this method, the patient's response to each sound sample can be monitored at any required sound level. All sound samples such as the 5 vowels, 13 consonant-vowel syllables, and sentences are stored in a computer as sound files. Any sound sample can be randomly selected to present to the examinee, who replies verbally. Interactive speech audiometry can provide a more accurate evaluation of speech discrimination in patients with hearing loss.

We assessed the possibility and limitations of preserving the larynx in the treatment of Supraglottic laryngeal carcinoma. Over the period from 1988 to 1997, we treated forty-one cases which included four T1, twenty T2, five T3 and twelve T4 patients. The three year preservation rates of the larynx and three year survival rates of the patients were 75% and 100% in T1 patients, 45% and 95% in T2, and 0% and 52.9% in T3 and T4 cases. Ordinary once-a-day radiotherapy was effective in T1N0 cases, but preservation of the larynx was possible in only 37.5% of T2N0 cases. Using hyperfractionated radiotherapy, the preservation rate was improved to 75%. Supraglottic hemilaryngectomy was available to three T2 cases, whose tumors were larger than 2 cm in diameter, but had not advanced downward over the aryepiglottic fold and had no lymph node metastasis. Five advanced cases of T2 with invasion to the glottis or lymph node metastasis needed total laryngectomy. As for T3, T4 cases, although total laryngectomy and bilateral neck dissection were performed in operable cases, the three year survival rate was poor. These observations suggest that it may be difficult to preserve the larynx in T3, T4 cases.

This paper discusses the cortical processing of speech recognition and the vocalization function from the results of previous PET studies, and speculates that the neuronal network encompassing the right ear, the left auditory area, and the cerebellum is engaged in accurate cognition of acquired speech, and the network of the left ear, right auditory area, and the supplementary motor area (SMA) is contributed to analyzing unknown language. A system of categorized word sounds may exist in the cerebellum, for the comparison and inspection of sound stimuli, which facilitates accurate and prompt cognition. On the other hand, for unknown speech sound, the SMA may propagate categorization of the sound input by analyzing the pattern of vocalization action.

The effects of a speech-coding strategy of cochlear implant (CI) on cortical activity were evaluated using positron emission tomography. The CIs used in the present study were those of a 22-channel system using the Multipeak speech-coding strategy (MPEAK) and the spectral peak strategy (SPEAK). On comparing the 2 groups, it was found that the speech-tracking performance was significantly higher in the SPEAK group than in the MPEAK group. Regional cerebral blood flow (rCBF) was measured during the silent resting, noise stimulus and speech stimulus periods. The increase in rCBF was localized mainly in the primary auditory area during the noise stimulus period. The increase in rCBF in the auditory association area during the speech stimulus period was stronger in the SPEAK group than in the MPEAK group. This finding suggests that the SPEAK strategy activates more speech processing neuronal networks in the auditory association area than the MPEAK strategy.

Videostroboscopic glottic measurements and vocal function were evaluated in 41 vocal fold atrophy patients with bowed vocal folds. The amount of bowing in the resting position and the glottal gap area and vibratory amplitude during phonation were measured from digitized videostroboscopic images. Vibratory amplitude was not decreased on atrophic vocal folds. With the same amount of total bowing, the glottal gap area for bilateral atrophy was smaller than for unilateral atrophy. These results suggest that vocal fold atrophy is not disadvantageous to thyroplasty type I, and that bilateral procedures may produce a better outcome than a unilateral procedure in the treatment of bilateral atrophy. Acoustic, aerodynamic, and perceptual parameters of vocal function were measured. The acoustic high-frequency power ratio and the H-index correlated with the glottal gap area. The mean flow rate correlated with the amount of bowing. The degree of dysphonia was related to the size of the glottal gap and bowing.

To elucidate the temporal coding system for speech recognition, we synthesized stimulation sounds which do not contain formant information but do contain temporal information by transforming original sound wave to click sequences. Using this stimulation sound, we performed a recognition test and used PET to examine the cortical activities in normal subjects listening to this sound. The results of the recognition test showed a good perception of the sounds made from sequential speech. The PET study demonstrated significant activation of the superior temporal gyri while listening to the stimulation speech sounds. Our results imply that these stimulation sounds were processed semantically in the auditory cortices. The temporal processing system is thought to make an important contribution to speech recognition.

The pectoralis major myocutaneous flap (PMMC flap) is extremely popular in head and neck reconstruction. This flap has many advantages over local cutaneous flaps, free flaps, and fasciocutaneous flaps. At our institute, this flap is the first choice among the various reconstructive methods used for the correction of tongue defects after primary tumor resection. We experienced synchronized contraction of the PMMC flap with adduction of the ipsilateral arm over a 1 year postoperative period. After severing of the nerves innervating the flap, this unusual contraction disappeared.

Over the last 4 decades remarkable progress has been made in the treatment of cleft palate: the rate of attaining normal or nearly normal speech after surgery has risen from about 65% 40 years ago to nearly 90% or more nowadays. One of the main factors is intratracheal intubation anesthesia that has made the surgery much safer and easier. Improved surgical technique and speech therapy also played a great role. This paper deals with two problems: (1) Slight velopharyngeal incompetence: The combined use of fiberscopy and fluorovideoscopy can provide useful information as to: (a) the exact place of the faulty articulation, (b) the detailed pattern of inconsistent velopharyngeal function, (c) changes in articulation induced by speech therapy, and (d) the relation between velopharyngeal function and faulty articulation. All the above information greatly facilitates speech therapy for cleft palate speech. It should be done with utmost care though due to possible adverse effects of radiation. (2) Analysis of faulty articulation. It was revealed that faulty articulations such as laryngeal fricative and affricates, pharyngeal stop, and glottal stop in cleft palate speech, secondary to velopharyngeal incompetence, were produced by articulation in the larynx at various sites such as the epiglottis, arytenoids, aryepiglottic folds and vocal folds. These faulty articulation points were located lower than supposed on the basis of auditory perception.

Thirty-eight patients suffering from tinnitus resistant to several medical therapies for more than 6 months were treated by low power laser irradiation. A 40 mW laser with a wavelength of 830 nm was irradiated via their external auditory meatus toward the cochlea for 9 min once a week, 10 times or more. Patients were asked to score their symptoms on a 5 point scale before and after the treatment for a subjective evaluation of the effect. The results were estimated by the change of the loudness and duration of tinnitus, and the degree of annoyance due to tinnitus. Although only 26% of the patients had improved duration, loudness and degree of annoyance were relieved in up to 58 and 55%, respectively, without major complication. Laser therapy seemed to be worth trying on patients with intractable tinnitus.

Imperfect glottal closure is usually the most important factor causing dysphonia in patients with bowing of the vocal folds. We have performed laryngeal framework surgery, which allows the medialization of the vocal folds from the outside without creating any scar tissue on them. Over the past 6 years, however, we encountered three cases with marked bowing of the vocal folds that could not be cured by laryngeal framework surgery alone. We used an open laryngeal procedure in these cases, even though such procedures had been considered contraindicated in the treatment of hoarseness. After performing a laryngofissure, we made a small pocket beneath the vocal fold mucosa at the anterior commissure. The superiorly based omohyoid muscle flap was then transposed into the mucosal pocket and sutured to the vocal process. This procedure should be considered an option in treating highly bowed vocal folds.