Retrograde mastoidectomy on demand with soft-wall reconstruction in pediatric cholesteatoma

金沢大学医薬保健研究域医学系Conclusion: Retrograde mastoidectomy with soft-wall reconstruction is an effective technique that can be used to lower the recurrence rate of cholesteatoma in the pediatric population. Objective: To evaluate surgical outcomes of retrograde mastoidectomy when using soft-wall reconstruction in pediatric cholesteatoma. Methods: A total of 25 children underwent cholesteatoma removal surgery employing soft-wall reconstruction. The cases were retrospectively reviewed. Average follow-up time was 48.7 months. In order to fully expose and extirpate the disease, the bony canal wall was removed in association with a retrograde-type mastoidectomy in all cases. The posterior ear canal defect was then reconstructed using soft tissue; i.e. temporal fascia and canal wall skin. The incidence and localization of residual and recurrent cholesteatoma, preoperative and postoperative audiogram results, pure-tone average (PTA), and airbone gap (ABG) were assessed. Results: Residual cholesteatoma was detected in 5 (20%) of 25 ears while recurrent cholesteatoma occurred in 1 (4%) of 25 ears. The mean preoperative PTA of air conduction (AC) was 39.1 dB, while the preoperative PTA of the ABGs was 28.8 dB. The mean postoperative PTA-AC and PTA-ABG were 20.9 dB and 11.7 dB, respectively. The mean hearing gain was 18.2 dB. The differences between the pre- and postoperative values were statistically significant (p < 0.05). © 2010 Informa Healthcare

Prognostic factors for squamous cell carcinoma of the temporal bone: Extensive bone involvement or extensive soft tissue involvement?

金沢大学医薬保健研究域医学系Conclusion: Extensive bone erosion correlated with a worse prognosis of the squamous cell carcinoma (SCC) of the temporal bone but extensive soft tissue involvement did not correlate with prognosis in this study. Resectability of the tumor seems to be major prognostic factor of temporal bone SCC. Objective: Prognostic factors for SCC of the temporal bone were evaluated regarding initial clinical symptoms and radiographic imaging. Patients and methods: Clinical symptoms of the patients with primary SCC of the external auditory canal (EAC) or middle ear (ME) were reviewed based on medical records. Correlation of clinical symptoms and cancer severity staging using the modified Pittsburgh classification was analyzed, along with disease-specific survival (DSS). Results: Sixteen patients with primary SCC of the EAC (n=13) or ME (n=3) were included in the study population. DSS was not influenced by whether a hearing disturbance or otalgia was noted at the first medical examination. Extended bone involvement identified with imaging studies significantly correlated with worse prognosis (p<0.05). Prognoses of patients without extensive bone erosion were good, and extensive (≥0.5 cm) soft tissue involvement did not correlate with prognosis in this study. Prognoses of patients with insufficient bone resection or no surgery were significantly poor (p<0.01)

Changes in calbindin-D28k and parvalbumin expression in the superior olivary complex following unilateral cochlear ablation in neonatal rats

金沢大学医薬保健研究域医学系Conclusion. Unilateral congenital deafness with a volume reduction in cochlear nucleus (CN) induced changes in the calcium-binding proteins (CaBPs) in the contralateral superior olivary complex (SOC) in the rat. With the loss of neurons and a volume reduction in the CN, a decrease in the input to the contralateral SOC may occur, which results in the down-regulation of CaBPs in these nuclei. This study may provide some implications regarding the neurochemistry in the auditory brainstem of deaf children. Objective. Hearing loss produced by cochlear damage during early development can result in persistent changes in the organization of the central auditory system in adults. The purpose of the present study was to investigate the neurochemical changes produced in the auditory brainstem of rats with unilateral cochlear ablation conducted before the onset of hearing. Materials and methods. Following unilateral cochlear ablation during early development, we examined the changes in the distribution of two CaBPs, calbindin-D28k (CB) and parvalbumin (PV), in the SOC. Results. Upon reaching adulthood, a marked decrease in CB- and PV-immunoreactive neurons was observed in the contralateral SOC, particularly in the medial nucleus of the trapezoid body (MNTB), although no neuronal cell death was observed. A volume reduction in the ipsilateral CN was also observed. © 2009 Informa UK Ltd

Anatomical plasticity in brainstem auditory nuclei following unilateral ablation of the inferior colliculus in neonatal rats

金沢大学附属病院耳鼻咽喉科Anatomical plasticity of projections from brainstem auditory structures to the inferior colliculus (IC) was examined in albino rats to determine the effects of unilateral destruction of the IC during early development. The IC in the right hemisphere was destroyed by aspiration on postnatal day 3. Upon reaching adulthood, the rats were examined by retrograde tract tracing methods with fluoro-gold (FG) and [3H]-glycine to determine patterns of brainstem projections to the undamaged left IC. In our FG experiments, the results confirmed the presence of aberrant crossed projections from the right medial superior olive (MSO) to the undamaged left IC. Following injections of [3H]-glycine or FG into the undamaged left IC, however, no other aberrant projections were found in the superior olive, including those from the ipsilateral lateral superior olive (LSO) or the superior paraolivary nucleus (SPN). These results suggest that projections from the MSO to the IC may have the latent ability to create aberrant crossed projections during development. On the other hand, the neurons in LSO and SPN do not form aberrant projections following early unilateral IC lesions. © 2008 Elsevier B.V. All rights reserved

Chondroblastoma of the temporal bone

Chondroblastomas are highly destructive tumors that are derived from immature cartilage cells. The occurrence of this tumor in the temporal bone or skull base is uncommon. Approximately 70 cases have previously been reported, several of which have involved the temporomandibular joint (TMJ). We report here the case of a 67-year-old woman who presented with right-sided mixed hearing loss, a right external auditory canal mass, ear fullness, otalgia, blood-stained otorrhea, and pain around the TMJ, associated with difficulty in opening the mouth. CT and MRI revealed a mass involving the TMJ, infratemporal fossa, and pterygopalatine fossa. The patient underwent tumor resection via an infratemporal fossa approach type B. Gross total tumor removal was achieved, with no facial nerve paralysis or other complications observed after surgery. No recurrence or residual tumors were observed on CT and MRI, even after 7.5 years of follow-up. We conclude that temporal bone chondroblastomas are extremely rare and aggressive, but the outcome after appropriate surgical treatment is favorable. From the review, it may be particularly important to deal with tumors that involve the TMJ, which could affect the long-term outcomes, as well as tumor recurrence. © 2011 Informa Healthcare

The effects of unilateral cochlear ablation on the expression of vesicular glutamate transporter 1 in the lower auditory pathway of neonatal rats

Objectives: Unilateral cochlear damage has profound effects on the central auditory pathways in the brain. Methods: We examined the effects of unilateral cochlear ablation on VGLUT1 expression in the cochlear nucleus (CN) and the superior olivary complex (SOC) in neonatal rats. Results: VGLUT1 expression in the CN subdivisions (the AVCN, the PVCN and the DCN-deep layers) and the SOC (the MnTB, the LSO and the MSO) ipsilateral to the ablated side was significantly suppressed by unilateral cochlear ablation. Interestingly, VGLUT1 expression in the PVCN and the DCN-deep layers contralateral to the ablated side was also reduced. Conclusion: Our findings indicate that unilateral cochlear ablation affects VGLUT1 expression in the central auditory pathways not only ipsilateral but also contralateral to the ablated side. © 2017 Elsevier B.V.in Press / Embargo Period 12 month

A case of chronic otitis media caused by Mycobacterium abscessus

金沢大学医薬保健研究域医学系Although it appears very uncommon in adult COM, Mycobacterium abscessus should be considered as a possible cause of a chronically draining ear. Multi-antibiotic chemotherapy including high-dose clarithromycin can effectively treat adult COM cased by M. abscessus. The first case report of adult chronic otitis media (COM) caused by M. abscessus is described here. A 61-year-old woman presented persistent otorrhea for 2 months, despite treatment with standard antimicrobial drugs. Physical examination revealed a small perforation of the tympanic membrane and edematous middle ear mucosa. Mycobacterial cultures and PCR yielded non-tuberculous mycobacteria (NTM); M. abscessus. Intravenous panipenem/betamipron and amikacin and oral clarithromycin were administered for 36 days. Computed tomography of the temporal bone showed improved aeration in the tympanic cavity, but soft tissue shadow remained unchanged in the mastoid 31 days after starting medication. She therefore underwent tympano-mastoidectomy at 36 days. At surgery, inflammation remained in the middle ear, and edematous pale mucosal tissue was noted around the stapes and ossicular chain. Histopathologic examination showed inflammation and granulation tissue, but no caseating necrosis or acid-fast bacilli. After surgery the symptoms resolved and remained well without evidence of infection recurrence 12 months after the operation. © 2010

Roles of epithelial-mesenchymal transition in squamous cell carcinoma of the temporal bone

金沢大学医薬保健研究域医学系Objectives: The authors recently demonstrated that extensive bone erosion correlated with a worse prognosis of the squamous cell carcinoma (SCC) of the temporal bone. The present objective was to investigate the expressions and the roles of epithelial-mesenchymal transition (EMT) in SCC of the temporal bone. Study Design: Retrospective patient file review and immunohistochemical study of tissues of patients with SCC of the temporal bone. Patients: The authors examined the expressions of vimentin in 16 patients with SCC of the temporal bone by immunohistochemical analysis. Results: As expected, vimentin was expressed on SCC of the temporal bone. We regard the patient who has vimentin-positive cells as EMT-positive patient because gain of vimentin is a hallmark in the EMT reported in several types of cancer. EMT positive tumors significantly correlated with extensive bone erosion, and extensive bone erosion correlated with a worse prognosis of the SCC of the temporal bone. Conclusion: The study results suggest that EMT in tumor cells becomes an important indicator of poor prognosis in SCC of the temporal bone. Copyright © 2011 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited

Clonal spread of β-lactamase-producing amoxicillin–clavulanate-resistant (BLPACR) strains of non-typeable Haemophilus influenzae among young children attending a day care in Japan

金沢大学医薬保健研究域医学系Objective: Resistant strains of non-typeable Haemophilus influenzae (NTHi) are one of the principal causes of recurrent acute otitis media (otitis prone), rhinosinusitis, and pneumonia in young children. β-Lactamase-nonproducing ampicillin-resistant (BLNAR) strains are particularly common in Japan, and β-lactamase-producing amoxicillin-clavulanate resistant (BLPACR) strains are now emerging. We investigated the nasopharyngeal carriage status of these resistant strains among children attending a same day care center during a 10-year period. Methods: From 1999 to 2008, we obtained nasopharyngeal swab specimens from young children attending a same day care center and examined the incidence of resistant strains of NTHi. Antimicrobial resistance of NTHi was identified based on PCR analysis of mutation of the penicillin binding protein (PBP) genes. Pulsed-field gel electrophoresis (PFGE) was performed to examine the clonal relationship of each resistant strain. Results: The prevalence of resistant strains of NTHi among the children attending this day care has significantly increased during the past 10 years and most of this day care children recently have resistant strains with PBP gene mutations in their nasopharynx. Genetically BLPACR (gBLPACR) strains have rapidly increased since 2007 and PFGE analysis demonstrated that all gBLPACR were clonally identical. This is the first report of apparent clonal dissemination of gBLPACR strains of NTHi occurring in a certain environment such as day care. Conclusions: The rapidly increasing prevalence of resistant strains, in particular gBLPACR, in this day care center may predict a high incidence of these resistant bacteria from clinical isolates in the near future and potential serious medical problems worldwide. © 2010 Elsevier Ireland Ltd