Tomoko Shintani

The effect of adenotonsillectomy in children with OSA

Adenotonsillar hypertrophy and abnormal facial morphology are thought to be important for the occurrence of obstructive sleep apnea syndrome (OSA). We evaluated the effects of adenidectomy and/or tonsillectomy and the relationship between the treatment results and facial morphology in 134 children with OSA. Significant improvements in apnea-hypopnea indes (AHI) and lowest blood oxygen saturation (SaO2) were noted and 78.5% of the patients improved after adenoidectomy and/or tonsillectomy. Additional operations were needed in two out of 13 cases of the adenoidectomy group and two out of four cases of the adeno-monotonsillectomy group. In the adenotonsillectomy group, the unimproved children tended to have smaller tonsils, narrower epipharyngeal airspace, and more poorly-developed maxillary and mandibular protrusion than the improved children.

Evaluation of the Role of Adenotonsillar Hypertrophy and Facial Morphology in Children with Obstructive Sleep Apnea

We evaluated the role of adenotonsillar hypertrophy and facial morphology in children with obstructive sleep apnea (OSA) and compared these data with an age-matched control group. We performed cephalometric analysis to evaluate facial morphology using lateral facilal roentgenograms. Adenotonsillar and maxillary hypertrophy was remarkable in OSA children. Maxillary protrusion was significantly smaller in the OSA group than in the control group in older children (5-9 years old). Mandibular protrusion was significantly smaller in the OSA group even at younger ages (1-2 years old). The hyoid bone was significantly lower in the OSA group than in the control group at age 3-6 years. Both environmental factors due to upper airway obstruction and genetic factors are suspected as causes of abnormal facial morphology in OSA children.

Aminoglycoside-Induced Hearing Loss in a Patient with the 961 Mutation in Mitochondrial DNA

The A1555G mutation in the mitochondrial 12S ribosomal RNA gene is often found in patients with hearing loss after aminoglycoside exposure. A second pathogenic mutation in this gene, deletion of thymidine at position 961 with varying numbers of cytosines inserted (delT961Cn), has recently been found to predispose patients to aminoglycoside-induced deafness. We report on a Japanese patient bearing the delT961Cn who had streptomycin-induced deafness. Our report suggests that the delT961Cn plays an important secondary role in the pathogenesis of deafness caused by aminoglycosides. The combination of taking family histories and molecular screening at the 1555 and 961 positions is thought to reduce the frequency of tragic irreversible deafness due to aminoglycosides.

Non-invasive positive pressure ventilation for laryngeal contraction disorder during sleep in multiple system atrophy

We examined the usefulness of non-invasive positive pressure ventilation (NPPV) in the management of nocturnal laryngeal stridor associated with vocal cord dysfunction in five cases of multiple system atrophy (MSA). First, the patients were investigated during sleep induced by a minimal dose of propofol. Laryngoscopy showed paradoxical vocal cord movement resulting in inspiratory stridor. Electromyographic (EMG) study revealed synchronized bursts in the thyroarytenoid muscles and diaphragm in every inspiratory phase whenever the stridor emerged. NPPV was initiated after paradoxical movement was recognized with laryngoscopy. The NPPV mask was equipped with an additional channel for laryngoscopic monitoring. The optimal pressure for treatment was determined according to laryngoscopic and EMG findings. Next, NPPV was applied to natural sleep using the conditions determined in propofol-induced sleep. In all cases, NPPV eliminated nocturnal stridor and oxygen desaturation during natural sleep. Laryngoscopic observation during induced sleep is recommended as a useful procedure to titrate the optimal pressure for NPPV therapy. Since central hypoventilation progresses in the course of MSA, the choice of NPPV rather than continuous positive airway pressure should be encouraged to treat laryngeal contraction disorder associated with MSA.

Middle Ear Imaging Using Virtual Endoscopy and Its Application in Patients with Ossicular Chain Anomaly

Virtual endoscopy (VE) is a recently developed technique to provide a realistic surface rendering of various organs, which can be applied to the use of three-dimensional (3D) studies of several lesions. However, its advantages in otological disease have not been well investigated. In this study, we evaluated the application of VE in patients with ossicular chain anomalies. Virtual middle ear endoscopy was a time-saving method, however, we needed the appropriate technical procedures of algorithm and reconstruction spacing to generate accurate 3D images of ossicles. We obtained virtual surgical views of middle ear structures and related anomalies, and confirmed by intraoperative findings that these images were mostly compatible with the actual lesions of ossicles. VE allowed an identification of the anatomy of the ossicles and adjacent structures simultaneously. The elements of the stapedial crura were clearly visualized with VE images in 93.3% of normal ears. Pathological ossicular chain findings such as malleus or incus fixation, dislocation and disruption, except footplate fixation were investigated successfully. One possible procedure, using alterable CT value in the obtained VE images on the monitor, is proposed for further detection of fine lesions of the ossicles. These observations suggest that virtual middle ear simulations accurately represent major intraoperative findings. This technique may have an important role in preoperative planning, surgical training, and/or postoperative evaluation in otology.

Surgical Strategy of Cochlear Implantation in Patients with Chronic Middle Ear Disease

We report 10 postlingually deafened adults in whom the electrophysical criteria for cochlear implant were fulfilled, except that they showed the following unfavorable middle ear lesions: otitis media with effusion, chronic perforative otitis media, cholesteatoma and previous radical ear operation. Staged operations for cochlear implant were performed in 8 cases, and 2 patients who had undergone radical ear operation had a single-stage operation. As a first step, one of the following was performed in each patient as surgically indicated: myringoplasty with or without mastoidectomy, mastoidectomy with reconstruction of the posterior wall of the external canal, mastoidectomy with the insertion of a ventilation tube, radical mastoidectomy or surgical cleansing of the radical cavity. From 6 months to 2.5 years after the first operation, the actual cochlear implant was performed in the second or third stage. There was no major complication as a result of electrode insertion into the cochlea and the results of speech perception in these cases were not different from those in patients with normal middle ears. In our experience, it was considered that the staged operations would enable successful cochlear implants in selected patients with pathological middle ear lesions even if they had previously been diagnosed as contraindicated for this procedure. In a case with radical ear cavity a single-stage operation could be performed when there was no cavity problem.

Epithelial barrier and antigen uptake in lymphoepithelium of human adenoids

Abstract Invasion of antigens through the mucosal surface can be prevented by the common mucosal immune system, including Peyers patches (PPs) and nasopharyngeal-associated lymphoreticular tissue (NALT). The adenoids (nasopharyngeal tonsils) comprise one of the NALTs and constitute the major part of Waldeyers lymphoid ring in humans. However, the role of the lymphoepithelium, including M cells and dendritic cells (DCs), in the adenoids is unknown compared with the epithelium of PPs. NALTs also have unique functions such as the barrier of epithelial cells and uptake of antigens by M cells and DCs, and may play a crucial role in airway mucosal immune responses. The lymphoepithelium of adenoids has well-developed tight junctions that play an important role in the barrier function, the same as nasal epithelium but not palatine tonsillar epithelium. Tight junction molecules are expressed in both M cells and DCs as well as epithelial cells, and various antigens may be sampled, transported, and released to lymphocytes through the cells while they maintain the integrity of the epithelial barrier. This review summarizes the recent progress in our understanding of how M cells and DCs control the epithelial barrier in the adenoids.

Obstructive sleep apnea by analysis of MRI findings

Abstract To predict the presence and the severity of obstructive sleep apnea (OSA), we studied 41 adult cases, using a dynamic MRI during sleep. We performed a quantitative analysis of the presence of occlusions and of the narrowing of the pharyngeal airway and soft tissue and compared the distance and area in each of the epi-, meso-, and hypopharynx levels in the awake and asleep conditions. The correlation between AHI, mean SpO 2 , lowest SpO 2 , body mass index (BMI), and the value of each measurement was assessed. In sleep, each airway distance was significantly narrower than the value when awake. The severity of AHI and SpO 2 are significantly correlated with the width of the airway space at the base of the tongue and hypopharynx. Obesity is an important factor in OSA because it affects the volume of the tongue and of the soft tissue of the hypopharynx. It is impossible to get information on the level of occlusion during sleep or on the severity of OSA by studying the patient in the awake condition. Therefore, dynamic MRI during sleep is useful to detect the level of occlusion during sleep and the severity of OSA, and this can assist in treatment.

Audiological chronological findings in children with congenital anomalies of the central nervous system

OBJECTIVE To determine the frequency of hearing impairment in children with congenital anomalies of the central nervous system (CNS) by using detailed audiological evaluation methods. METHODS The patients were 78 children with congenital anomalies of the CNS with a mean age of 29.5 months. They had been observed for a mean period of 38.5 months. Hearing levels were evaluated behavioral observation audiometry (BOA), visual reinforcement audiometry (VRA) and distortion product otoacoustic emissions (DPOAEs) were performed. Auditory brainstem responses (ABRs) and computed tomography (CT) scans of the temporal bone were performed in the cases in which the minimum response levels (MRLs) were above 30 dBHL. All cases were assessed in terms of developmental age. RESULTS A total of 14.1% (11/78) of the children with congenital anomalies of the CNS were initially diagnosed with bilateral sensorineural hearing loss (SNHL). However, the hearing levels of nine of them improved by the time of the last diagnosis. Therefore, the patients with bilateral SNHL were only 2.6% (2/78) of the total patients with congenital anomalies of the CNS at last diagnoses. As shown by our results, many children with bilateral SNHL at initial diagnosis showed improved ABR thresholds and behavioral hearing thresholds with age. In this series, the use of hearing aids was arranged for six patients. However, four patients stopped using hearing aids when their hearing threshold levels improved. In two cases, there were no changes in hearing levels and the children continued using hearing aids. CONCLUSION Our results suggest that hearing level recovery can occur in some children with CNS anomalies. Confirmation of hearing loss in children with congenital anomalies of the CNS takes a long time. There are improvements in hearing loss during the observation period. Therefore periodic assessment of hearing is important.

Relation between Vestibular Function and Speech Recognition in Postlingually Deafened Adults with Cochlear Implantation

Thirty-one postlingually deafened adults with 22-channel cochlear implants were evaluated preoperatively using vestibular function tests, the caloric test and stabilometry. The results of caloric response were classified into two diagnostic groups: normo- or hyporeflexia and areflexia. Stabilometric recordings were made using a computerized static posturographic platform. Between the two categories of caloric response, there was a significant difference in consonant recognition, but the recognition of vowels showed no significant difference. The results of the distance of body sway in stabilometry, but not of the area, correlated to the results of consonant recognition in speech perception tests. The degree of residual vestibular function seems to be one of the indicators influencing postoperative speech recognition by cochlear implant patients.