Speech analysis methods can be divided into two classes, parametric and nonparametric. The parametric method includes a speech production model in the analysis process, while the nonparametric method does not. The former is exemplified by the well-established linear prediction analysis and the latter often utilizes short-term Fourier analysis. Recent progress in speech analysis methods can be found in an ARX (Auto-regressive with exogenous input) method, a parametric approach, as well as STRAIGHT (Speech Transformation and Representation using Adaptive Interpolation of weighted spectrum) method, a nonparametric approach. The ARX method incorporates a sophisticated ARX-based speech production model, making it possible to separately estimate glottal flow parameters and formants. Basic and clinical applications of the ARX method are presented in the field of voice and speech disorders, including acoustic evaluation of dysarthria, esophageal voice and dysphonia.
A questionnaire survey of the incidence of vocal cord nodule (VCN) in children during the last year and the policies with regard to its treatment was made on selected medical institutions in Japan, and 54 replies were collected. The total number of VCN in children was 138. That is an average 2.5 cases per institution per year. The most common cause of VCN was reported to be shouting (72%). As for the policy of treatment of VCN in children, a regular follow-up was most common (56%), followed by leaving it alone (21%) and voice therapy (19%), while surgical removal was made only in 2 cases (1%). It appears to be difficult to establish a definite policy of treatment of VCN particularly because the system of voice treatment is still immature in Japan, and a long-term follow-up is often impossible. The surgical approach may be taken into consideration in strictly selected cases in future.
Juvenile laryngeal papillomatosis develops between the ages of 6 months and 4-5 years and runs a multiple and recurrent clinical course. There were 61 patients with laryngeal papillomatosis treated at Keio university hospital during the 20-year period between May 1981 and May 2001, of whom 20 patients were under the age of 15 at onset. The average number of repeated operations they received was 18.1, showing the pronounced multiple, recurrent trend of this disease. Treatment is basically laryngomicrosurgery using a CO2 laser, and attempts should be made to conserve normal mucosa as much as is practicable as well as to improve phonation and respiratory function, in addition to targeting the total resection of the tumor. As the human papilloma virus, which is etiologically responsible for the formation of papillomas, grows in the mucosal epithelium, it is in principle, sufficient to vapolize the epithelial layer alone, avoiding a deeper intervention than is required. Tracheostomy should be avoided wherever feasible because it may cause tumor dissemination. Development of effective adjuvant therapy, besides surgery, is also generally anticipated. Efficacy of interferon-α in this disease has been demonstrated and indole 3 carbinol (I3C), a major component of cabbage, and the antiviral agent cidofovir are also currently used. Independently, we focused on Chinese medicines, prescribing this type of herbal medicines in anticipation of their effects for contraction of residual tumor and preventive effects against recurrence. It is worth noting that favorable results have been observed in 6 of the 10 patients receiving Chinese medicines whose therapeutic responses could be evaluated.
Recurrent laryngeal nerve paralysis in children is a relatively rare disease. Its clinical features in children are considered dissimilar to those in adults. Here we present 11 cases of children with recurrent laryngeal nerve paralysis and discuss the manner of treatment for this disease. Clinical features compared and found to differ with those in adults are summarized as follows : 1) congenital paralysis is the most common cause, 2) bilateral paralysis is frequent, 3) congenital systemic abnormalities are frequently combined, 4) respiratory disorder is the most critical symptom especially in infants, 5) vocal cord movement ordinarily recovers in a few years especially in patients with congenital paralysis. Management strategies should be focused on the maintenance of a safe and stable airway and the acquisition of intelligible speech. Less traumatic laterofixation of the vocal cord by Ejnell's procedure is a preferable surgical treatment for prolonged respiratory disorder due to bilateral laryngeal paralysis.
Various controversial problems have been pointed out for the treatment modality for patients with cicatricious stenosis of the larynx as follows : 1) successive change of the autografted mucosa and/or skin, 2) timing of complete closure of the tracheostoma, 3) influence of puberty upon the air-way, and 4) influence of puberty upon vocal functions. Thirty-six patients more than 15-year-old and 23 patienets less than 15-year-old, both with cicatricious stenosis of the larynx, were retrospectively reviewed in this study. As a result, following conclusions were obtained.1) Autografted mucosa/skin can be alive accompanying prominent cicatricious change below the grafted mucosa/skin, suggesting this histopathological change may bring re-stenosis of the air-way. 2) The trachestoma should be closed preferably after puberty, especially for patients undergoing posterior cricoid split (PCS) maneuver. For patients without PCS complete closure in childhood may cause no serious problem. 3) Patients treated their stenosis in childhood may have no restenosis of the air-way even in adulthood. 4) Patient with laryngeal stenosis may experience voice change at puberty as like ordinary children.
Computed tomography (CT) is still the mainstay of imaging diagnosis for laryngeal carcinoma. Presented herein are the typical CT protocols for laryngeal carcinoma, the normal CT imaging of subglottis and a CT diagnosis of the subglottic extension of the laryngeal carcinoma, respectively. CT images are usually obtained after the administration of an intravenous contrast material with a slice thickness of 2 mm, intersection gap of 1-3mm and a field of view (FOV) of 14-16cm to evaluate the primary site of the laryngeal carcinoma. It is most important to obtain CT images parallel to the plane of the true cord for the accurate evaluation of the subglottic extension. The air-density lucency of the laryngeal ventricle, C4/5 or 5/6 intervertebral disc space, and the hyoid bone on the lateral scout view can be reference of the plane parallel to the true cord. Air-attenuation in the subglottic lumen directly abuts upon the internal surface of the cricoid cartilage on axial CT images of the normal larynx. Any soft tissue swelling adjacent to the cricoid cartilage is abnormal. The coronal and/or sagittal images on the multi-planar reformation well demonstrated the extent of tumor spread in the selected cases.
A clinico-pathological study of the extension to the subglottic area of the larynx was performed in T3 or T4 laryngeal cancer patients who received total laryngectomies at Kurume University Hospital between 1991 and 1997. There were 63 (21 glottic and 42 supraglottic) patients during this period and the following results are obtained : 1) The frequency of metastasis to the paratracheal or prelaryngeal lymph nodes was 29% in glottic cancers, and 10% in supraglottic cancers. 2) The frequency of metastasis to the paratracheal or prelaryngeal lymph nodes increased to 56% (glottic cancers) and 40% (supraglottic cancers) for those patients whose tumor extended to the subglottic area of the larynx. 3) In cases that were free from subglottic extension but CA invasion was detected, paratracheal or prelaryngeal lymph node metastasis was found in 50% of glottic and 33% of supraglottic cancer patients. 4) There was no metastasis to the paratracheal or prelaryngeal lymph nodes when the examined glottic and supraglottic cancers were free from invasion to both the subglottic and CA. 5) From these findings, we submit that the distance of the subglottic extension of laryngeal cancer is more than 10mm at the anterior commissure and was less than 10mm at the membranous vocal cord and the posterior commissure. 6) Dissection of the paratracheal lymph nodes as well as postoperative radiation is thought to be highly beneficial for preventing stomal recurrence.
Subglottic extension is one of the factors affecting the directions of treatments for patients with glottic cancer. The way in which the tumor involves the subglottic region may limit laryngeal preservation and affects the necessity of paratracheal dissection. The purpose of this paper is to assess the necessity of paratracheal dissection and also to evaluate how tumors invade deep structures of the larynx as well as the subglottic region. In this study, a series of 116 cases with glottic squamous cell carcinoma treated at our institution from January 1990 to December 1999 were reviewed. Of those patients, 87 had T2 tumors without paratracheal metastasis. The remainder included 14 patients with T3 tumors and 15 patients with T4 tumors. Paratracheal dissection was indicated for 23 patients (T3 : 8, T4 : 15) and paratracheal metastasis was pathologically confirmed in 4 patients (T3 : 1, T4 : 3). All the patients with pathological paratracheal metastasis were found to be at Grade 3 or 4 of Yoshino's subglottic extension grading. Based on this result, paratracheal dissection should be applied in patients with Grade 3 or 4 subglottic extension. Furthermore, pathological study on sections of 23 larynges described above suggested the importance of careful surgical approaches, especially to tumor dominantly involving the posterior portion of the larynx.
Over a 16-year period, from 1980 though 1995, 41 patients with T2 glottic squamous cell carcinoma (SCC) with subglottic extension were treated at the National Cancer Center Hospital. The treatment modalities included radiotherapy, partial laryngectomy (P.L), and total laryngectomy (TL). The treatment results were analyzed to determine a strategy for management of T2 glottic SCC with subglottic extension. The indication of radiotherapy in these patients was limited in cases with superficial and small subglottic extension. TL was required in a majority of the patients with recurrent carcinoma after radiotherapy. TL should be initially required for patients with invasion of cricothyroid ligament and with subglottic extension over 1cm in diameter at the posterior part of the vocal cord. PL was the first choice of the treatment in a majority of the patients without superficial and small subglottic extension nor invasion of cricothyroid ligament. The local control rates and the laryngeal preservation rates were 70% and 70% with PL, versus 40% and 50% with radiotherapy. The correct diagnosis of subglottic extension via long laryngo-bronchofiberscope was very important to determine the modality of treatment.
This study involved 424 patients with laryngeal cancer who underwent primary treatment during the 21-years period from 1978 to 1998. This group of patients comprised 401 males and 23 females, and ranged in age from 37 to 89 years with a mean age of 64.7 years. Among the 424 patients, 285 had glottic cancer. The subglottic region was defined as the area from 10 mm inferior to the free border of the vocal cords to the inferior border of the cricoid cartilage. Subglottic extension was noted in 23 of 81 cases (28.4%) at stage T2, 15 of 30 cases (50%) at stage T3, and 2 of 2 cases at the T4 stage. At T2, in the presence of subglottic extension, a total laryngectomy was performed in only 13 of 58 cases (22.4%), along with conservative treatment, especially radiotherapy, being frequently employed. At T3, total laryngectomy was frequently performed irrespective of the presence or absence of subglottic extension, and a partial resection was performed in 1 patient with subglottic extension, and in 4 cases without subglottic extension. Of the cases that were operated on, lymphatic metastasis was detected in 4 of 15 patients with subglottic extension at stage T2, and paratracheal lymphatic metastasis was recognized in 2 of the 4. Lymphatic metastasis was observed in 5 of 13 patients at stage T3, and paratracheal lymphatic metastasis in one. A laryngectomy was performed in patients with no subglottic extension, with whom lymphatic metastasis was occasionally observed but without paratracheal lymphatic involvement. The difficulty with larynx-trachea resection is problematic tracheal stoma construction after resection. This is associated with impeded blood flow resulting from peritracheal detachment, tension of suture due to unnatural raising of trachea, and anastomotic dehiscence at the tracheal stoma. Countermeasures against these problems accordingly include extensive tracheal resection with the addition of sternum resection, reduction of suture tension by constructing tracheal stoma at a lower position, and tracheal stoma construction with reconstructive material such as a musculocutaneous flap to prevent blood flow.
Laryngostroboscopy is one of the most useful clinical examination techniques in laryngology. We performed clinical tests of a trial laryngostroboscope system along with a videoendoscope. The system is composed of a videoendoscope, a video processor (PENTAX, EPK-700), a laryngostroboscope (Nagashima, LS-3A), a video recorder and a color printer. The videoendoscope has a small color charge coupled device (CCD) chip built into the tip of the endoscope. The outer diameter of the tip of this scope is 4.1mm. The endoscope was inserted through the nasal passage. Compared with Laryngostroboscopy using conventional flexible fiberscopy or rigid endoscopy, this system has several advantages. The videoendoscope shows clear, dynamic color images on a video monitor and provides excellent resolution and recording, and thus leading to its high diagnostic accuracy. The patient is allowed to phonate holding a normal head position thereby producing varying vocalization in a habitual and normal manner during examination. The diameter of this videoendoscope is relatively small, resulting in less discomfort for patients, even those that are children. Pernasal endoscopy enables the examination of patients with a strong gag reflex, an omega-shaped or infantile epiglottis, thus lessening limitations in the range of subjects for examination. Documentation of stroboscopic images is very useful for explanation of the disease to the patient. Laryngostroboscopy using a videoendoscope is a reliable procedure of stroboscopic examination of vocal fold vibration.
In a partial laryngectomy for T3 glottic cancer, a new method was developed for reconstructing the defects of the arytenoid region and the cricoid arch using parts of the thyroid cartilage and hyoid bone. After removal of the arytenoid region including the arytenoid cartilage and a periarticular region of the cricoid cartilage, a lateral half of the thyroid cartilage on the affected side, attached to the thyropharyngeal and sternothyroid muscles was utilized in the construction of a posterior-lateral wall of the larynx by way of suturing it with the incised end of the cricoid cartilage. After resecting the subglottis with an arch of the cricoid cartilage, a segmental defect of the cricoid cartilage was bridged by using half of the hyoid bone connecting to the sternohyoid muscle. Raw surfaces of the thyroid cartilage and the hyoid bone were covered with skin flaps of the anterior neck. This surgery was performed for a patient with T3 glottic cancer. Two months after surgery, the stoma was closed without respiratory disturbance. Normal food intake was possible. A hoarse voice remained, but phonatory function was fairly good.
Nineteen patients with transglottic cancer were reviewed, between September 1986 and December 1999. They were classified as T2 in 8 patients, T3 in 7, T4 in 4, N0 in 13, N1 in 2 and N2 in 1. All patients underwent total laryngectomy with modified neck dissection including one patient in whom a full course of radiation therapy failed. The five-year survival rate was 68.4%. Main cause of death was distant metastases. There were no difference in survival rates between lateral type and anterior type. There was a significant difference in survival rates between the group without neck metastasis and the group with neck metastases. We indicated the poorer prognosis for cases with transglottic cancer rather than other types of laryngeal cancer, and stressed the difficulty of early diagnosis and treatment.
Six patients with unilateral vocal fold paralysis underwent type I thyroplasty using an expanded polytetrafluoroethylene (Gore Tex®) patch for improvement of hoarse vocalization. Voice quality was successfully improved in all patients. Gore Tex® is a well-proven material, easy to trim and insert, therefore it is very useful for type I thyroplasty.
Adenoid cystic carcinoma of the larynx is very rare and only 31 cases have been reported in Japanese literature in the last 30 years. A 44-year-old-woman complained of hoarseness and dyspnea. Fiberscopic examination revealed fixation of the right vocal cord and a smooth mass involving the subglottic area. An excisional biopsy was performed with laryngeal microsurgery. The pathological diagnosis was adenoid cystic carcinoma. The patient underwent total laryngectomy with a right modified neck dissection and subsequent radiation therapy of 50 Gy. She has remained well for the last 24 months without any evidence of recurrence and metastasis.
A case of a 61 year-old male with a saccular cyst is reported. In the course of treating his laryngeal cancer (T1N0M0), the saccular cyst manifested itself after CO 2 laser vestibulectomy, named by Kashima, preceding laryngomicrosurgery with CO 2 laser cordectomy. Although the shapes of both the vocal and vestibular folds were restored normally up to 3.5 months after the surgery, the shape and the size of the vestibular fold increased in size after 4.5 months, and further continued to enlarge even after 6 months. The post-operative retention cyst was diagnosed radiologically via the findings of laryngeal MRI scans that included contrast-enhanced Ti-weighted imagery showing low-signal-intensity without enhancement, along with T 2-weighted imagery showing high-signal-density. The cyst was extracted by CO 2 laser-laryngomicrosurgery. It was covered with a thick wall of normal membrane and existed beneath the membrane of the vestibular fold. The cyst was comprised of a blue, transparent and gluey secretion. Microscopic examination of the specimen revealed that the inner wall of the cyst was lined with columnar epithelium, namely, respiratory epithelium. The resulting diagnosis was retention cyst pathologically, and saccular cyst, classified by De Santo, clinically. Recurrence was not found 12 months after the extraction.
A rare case of angioleiomyoma of the larynx is presented. The patient was a 71-year-old man with a chief complaint of bloody sputum. Laryngoscopy showed a globular tumor-like swelling of the right false cord at the margin of the aryepiglottic fold and arytenoid. The tumor was covered with normal mucosa. After tracheotomy, biopsy was performed under laryngomicroscopy. Histopathologically, the tumor mass composed of proliferating smooth muscle fibers and dilated blood vessels. The tumor was diagnosed as an angioleiomyoma. The tumor was removed completely by an external surgical approach and the bleeding was controlled. It was measuring 1.9×2.0×2.7cm. The patient has shown no evidence of recurrence over a 1 year and eight month period. Our extensive survey of the literature revealed 18 reports of angioleiomyoma of the larynx. Angioleiomyoma is a benign tumor. However, after the leiomyoma of the hypopharynx was removed, the tumor was recurrent as a leiomyosarcoma. And Two cases were recurrent because of incomplete resection. It suggests that complete resection of these lesions is important and that the patients showed be monitored for recurrence on a regular basis after surgery.