Isolated Congenital Round Window Atresia: Report of 2 Cases.

Round window atresia (RWA) is an uncommon condition and can result in a conductive hearing loss. Two cases of nonsyndromal bilateral RWA in 2 members of the same family are reported. Both cases presented with a conductive hearing loss of 20 to 30 dB. High-resolution computed tomography scanning was used to diagnose the condition. The patients were rehabilitated with hearing aids. Review of the literature has shown disappointing results in hearing improvement with cochlear fenestration in an attempt to address this condition. Patients presenting with unexplained conductive hearing loss should be offered computed tomography scanning. The cases we report add to the literature to benefit future patients in preoperative counseling and better inform management.

The Forgotten Second Window: A Pictorial Review of Round Window Pathologies.

The round window serves to decompress acoustic energy that enters the cochlea via stapes movement against the oval window. Any inward motion of the oval window via stapes vibration leads to outward motion of the round window. Occlusion of the round window is a cause of conductive hearing loss because it increases the resistance to sound energy and consequently dampens energy propagation. Because the round window niche is not adequately evaluated by otoscopy and may be incompletely exposed during an operation, otologic surgeons may not always correctly identify associated pathology. Thus, radiologists play an essential role in the identification and classification of diseases affecting the round window. The purpose of this review is to highlight the developmental, acquired, neoplastic, and iatrogenic range of pathologies that can be encountered in round window dysfunction.

Effect of Oval Window Blockage on Bone Conduction in Cadaver Heads.

OBJECTIVE: This study aimed to explore the feasibility of medical adhesive in the molding of oval window (OW) blockage in cadaver heads and to study the effect on bone conduction (BC). METHODS: Four cadaver heads were selected to establish OW blockage model. The daub type of medical adhesive was used to immobilize OW. The vibration properties of the round window membrane (VRWM) in response to the acoustic stimulation, and the vibration properties of the round window membrane and cochlear promontory (VCP) in response to the BC transducer B-71 stimulation were assessed by laser Doppler vibrometer in both pre-OW blockage and post-OW blockage. RESULTS: After blocking the oval window, the mean values of the sound-induced velocities amplitude responses of the round window membrane by air conduction were decreased significantly beyond 30 dB in all measured frequencies (p < 0.05). The round window membrane relative velocity (VRWM/VCP) shows a decrease of about 1 dB at 1 and 3 kHz frequencies and a slight increase of around 0.5 dB from 4 to 8 kHz frequencies in post-OW blockage. However, it should also be noted that the VRWM/VCP is a significant decrease of 1.2 dB at 3 kHz in post-OW blockage compared with pre-OW blockage (p < 0.05). CONCLUSION: Medical adhesive was available for the immobilization of oval window. In cadaver heads, the effect of OW blockage on the BC was the notching at 3 kHz.

Cochlear-Internal Canal and Cochlear-Facial Dehiscence: A Novel Entity.

Different types of otic capsule dehiscence restricted to the cochlea have been described. Here we describe the case of a patient with a cochlear-internal auditory canal dehiscence associated with a cochlear-facial dehiscence not reported before. A 53-year-old patient with severe to profound sensorineural hearing loss due to bilateral Meniere's disease underwent a cochlear implant surgery on the right ear. Preoperative brain magnetic resonance imaging findings were reported to be normal; during surgery, a cerebrospinal fluid gusher occurred at the time of round window opening. Postoperative computed tomography imaging showed a bony dehiscence at two levels of the otic capsule.

Round Window Occlusion Affects Bone Conduction in Cadaver Heads.

OBJECTIVE: To explore the feasibility of ear mold glue in the molding of round window occlusion (RWO) in cadaver heads and to study the effect on bone conduction (BC). METHODS: Ten cadaver heads were selected to establish RWO model. Ear mold glue was used to immobilize round window niche. The vibration properties of the stapes footplate (VST) in response to the acoustic stimulation, and the vibration properties of the stapes footplate and cochlear promontory (VCP) in response to the B-71 stimulation were assessed by laser Doppler vibrometer in both pre-RWO and post-RWO. RESULTS: The mean velocities of the stapes footplate in response to the acoustic stimulation in post-RWO were decreased significantly beyond 14 dB for frequency from 0.5k to 3k Hz and decreased beyond 11 dB for frequency above 4 kHz compared with pre-RWO (p<0.05). The stapes footplate relative velocity (VST/VCP) for pre-RWO and post-RWO conditions showed almost no difference (the difference was around 0.5 dB for 0.5k, 1k, 2k, 5k, 6k, and 7k Hz frequencies), except a slight decrease of around 1.5 dB at 3k and 8k Hz frequencies in post-RWO. However, the VST/VCP was a significant decrease of 1.7 dB at 4k Hz in post-RWO compared with Pre-RWO (p<0.05). CONCLUSION: Ear mold glue was available for the immobilization of round window niche in cadaver heads. The RWO have an impact on the BC hearing threshold. The effect of RWO on the BC was similar to that of otosclerosis, but the feature frequency for the depressed BC threshold at 4k Hz.

CT findings of the temporal bone in CHARGE syndrome: aspects of importance in cochlear implant surgery.

To provide an overview of anomalies of the temporal bone in CHARGE syndrome relevant to cochlear implantation (CI), anatomical structures of the temporal bone and the respective genotypes were analysed. In this retrospective study, 42 CTs of the temporal bone of 42 patients with CHARGE syndrome were reviewed in consensus by two head-and-neck radiologists and two otological surgeons. Anatomical structures of the temporal bone were evaluated and correlated with genetic data. Abnormalities that might affect CI surgery were seen, such as a vascular structure, a petrosquamosal sinus (13 %), an underdeveloped mastoid (8 %) and an aberrant course of the facial nerve crossing the round window (9 %) and/or the promontory (18 %). The appearance of the inner ear varied widely: in 77 % of patients all semicircular canals were absent and the cochlea varied from normal to hypoplastic. A stenotic cochlear aperture was observed in 37 %. The middle ear was often affected with a stenotic round (14 %) or oval window (71 %). More anomalies were observed in patients with truncating mutations than with non-truncating mutations. Temporal bone findings in CHARGE syndrome vary widely. Vascular variants, aberrant route of the facial nerve, an underdeveloped mastoid, aplasia of the semicircular canals, and stenotic round window may complicate cochlear implantation.

Congenital oval or round window malformations in children: Surgical findings and results in 17 cases.

OBJECTIVES/HYPOTHESIS: To prospectively evaluate surgical findings and hearing results in children undergoing surgery for congenital oval or round window malformations (class IV malformations). STUDY DESIGN: A nonrandomized, nonblinded, case series of prospectively collected data. METHODS: Fourteen consecutive pediatric patients who underwent 17 surgical procedures for congenital oval or round window malformations in a tertiary referral center were included. Postoperative pure-tone audiometry was available in 15 cases. The surgical technique for repair of the ossicular chain was dictated by the surgical findings at the time of surgery. The majority of the cases underwent ossiculoplasty using a Teflon piston, bucket-handle prosthesis, or total ossicular replacement prosthesis. Associated surgical techniques included malleus relocation and oval window drill-out procedure. The main outcome measures were preoperative and postoperative hearing status using four-frequency (0.5, 1, 2, and 4 kHz) audiometry. Air-conduction thresholds, bone-conduction thresholds, and air-bone gap were measured. Postoperative audiometry was performed at 3, 6, 9, 12, 18, and 24 months after surgery and at a yearly interval thereafter. RESULTS: Postoperative air-bone gap closure to 10 dB or less was achieved in 47%. A postoperative air-bone gap closure to within 20 dB or less was achieved in 60%. Postoperative sensorineural hearing loss did not occur in this series. CONCLUSIONS: Middle ear surgery for class IV abnormalities is feasible, but success percentages are much lower compared to other types of congenital ossicular malformations. Surgeons should be particularly careful in case of facial nerve abnormalities on computed tomography or during middle ear exploration. LEVEL OF EVIDENCE: 4 Laryngoscope, 126:2552-2558, 2016.

The location of the mastoid portion of the facial nerve in patients with congenital aural atresia.

In order to investigate the location of the mastoid portion of the facial nerve in patients with congenital aural atresia and to assess its effect on the round window middle ear implant (MEI) transducer implantation approach, 70 patients with unilateral congenital aural atresia were examined by computer tomography (CT). The patients were divided into two groups based on their ages: 44 patients in Group A (2-12 years) and 26 patients in Group B (13-29 years). CT scans were reviewed for each patient. Based on the CT findings, the mastoid portion of the facial nerve's spatial configuration with respect to the oval and round windows was qualitatively recorded. Additionally, the exact location of the facial nerve was measured quantitatively. The results suggested that of the 70 deformed ears, 57 had facial nerves located at the round window, six at the oval window, and seven at the normal site. Of the 70 normal opposite ears, 63 had facial nerves located at the normal site, and the other seven had facial nerves located at the round window. Based on the quantitative measurements, the mastoid portion of the facial nerve was more anteriorly positioned in the deformed ears: 3.44-6.09 mm more anteriorly located in Group A and 4.35-7.41 mm more anteriorly located in Group B. In conclusion, in patients with congenital aural atresia, the dislocation of the facial nerve could have significant effects on the surgical approach to round window MEI transducer implantation.

Cochlear implantation in children with "CHARGE syndrome": surgical options and outcomes.

CHARGE syndrome is a rare, polymalformative disease, representing one of the major causes of associated blindness and deafness. Bilateral, severe-profound, sensorineural hearing loss is common in CHARGE children. Aim of this study is to present our results in children with "CHARGE syndrome" submitted to cochlear implantation (CI). The frequency of anatomic anomalies, possible variations in the surgical technique of CI, and the audiological/rehabilitative benefits attained in our patients are reported. we submitted 5 children affected by CHARGE syndrome with profound, bilateral, sensorineural hearing loss to CI. Otoacoustic emissions, auditory brainstem response, acoustic impedance testing, cranial computed tomography and magnetic resonance were carried out preoperatively in all children. CI was performed using the mastoidotomy-posterior tympanotomy approach in two cases, and the suprameatal approach in three children. Infant toddler-meaningful auditory integration scale was used to evaluate kid's audiological performance before and after CI. Intra-operatory findings and postsurgical complications were evaluated. Among our patients, intraoperative anatomical malformations were cochlear hypoplasia (100 %), ossicles malformations (100 %), semicircular canals aplasia (100 %), oval window atresia (60 %), round window atresia (40 %), widening of the aqueduct of the vestibule (20 %), and aberrant course of the facial nerve (20 %). No intra- or postoperative complication was recorded in relation to implant positioning. After a follow-up ranging from 1 to 4.5 years, only 2/5 patients used oral language as the sole mean of communication, 1 started utilizing oral language as the main mean of communication, while 2 patients did not develop any linguistic ability. In conclusion, CI in patients with CHARGE association is feasible and, despite results variability, it should be carried out in CHARGE children with severe hearing loss as soon as possible. Although the selection of a specific surgical technique does not seem to influence the audiological outcome, the suprameatal access is valuable when important surgical landmarks (i.e. lateral semicircular canal and incus) are absent.

Congenital oval or round window anomaly with or without abnormal facial nerve course: surgical results for 15 ears.

OBJECTIVES: To describe the audiometric results in a consecutive series of patients with congenital ossicular aplasia (Class 4a) or dysplasia of the oval and/or round window (Class 4b), which might include a possible anomalous course of the facial nerve. STUDY DESIGN: Retrospective chart study. SETTING: Tertiary referral center. PATIENTS: A tertiary referral center study with a total of 14 patients with congenital minor ear anomalies as part of a consecutive series (n = 89) who underwent exploratory tympanotomies (15 ears). MAIN OUTCOME MEASURES: Audiometric results. RESULTS: In 8 of 15 ears, ossicular reconstruction was attempted. In the short term (1 mo), there was a serviceable hearing outcome (air-bone gap closure to within 25 dB) in 4 ears. However, the long-term results showed deterioration because of an increased air-bone gap in all but 1 ear. No facial nerve lesion was observed postoperatively. CONCLUSION: Congenital dysplasia or aplasia of the oval and/or round window is an uncommon congenital minor ear anomaly. Classical microsurgical opportunities are rare in this group of anomalies. Newer options for hearing rehabilitation, such as the osseointegrated passive bone conduction devices, have become viable alternatives for conventional air conduction hearing devices. In the near future, upcoming active bone conduction devices might become the most preferred surgical option. In cases in which the facial nerve is only partially overlying the oval window, a type of malleostapedotomy procedure might result in a serviceable postoperative hearing level.

[Recurrent meningitis in inner ear malformations]. / Nawracajace zapalenia opon mózgowo-rdzeniowych w wadach wrodzonych ucha wewnetrznego.

Authors present two cases of children with reccurent meningitis and unilateral deafness. Implemented diagnostics (CT, NMR, ABR) revealed one side inner ear congenital malformation in one case and anterior fossa bony defect accompanied by labirynthine deformation in the other case. The presence of perilymphatic fistulae in oval and round windows and cerebrospinal fluid leakage has been confirmed in both cases during surgery. Carefull obliteration of the Eustachian tube and both windows has been performed. Non- complicated postoperative course (2 months and 6 years - respectively) has prooved the effectiveness of applied treatment.

Non-syndromal round window atresia: an autosomal dominant genetic disorder with variable penetrance?

Round window atresia can be seen in association with syndromal anomalies such as mandibulofacial dysostosis, Mondini type anomalies or cretinism, or with extensive otosclerosis. Non-syndromal round window atresia is extremely rare and until today there is no proof whether non-syndromal round window atresia can be inherited. We present two family members with non-syndromal round window atresia. Based on this case and on an extensive literature review, we discuss the possible ways of sound transmission with round window occlusion as well as the possibility of an autosomal dominant inheritance pattern of these two non-syndromal cases. Evaluating the hearing test results, the effect of round window atresia in non-syndromal cases cannot be thoroughly explained by current theories of sound transmission. In general, full occlusion of the round window should result in a complete air-bone-gap and a surgical procedure to open the window, e.g. a cochlear fenestration which creates a new pressure outlet for the inner ear fluids, should result in normalizing the hearing levels. Astonishingly, patients with non-syndromal round window atresia, show hearing tests similar to those in patients with otosclerosis. In contrast to otosclerosis, complete closure of the air-bone-gap by surgery in patients with round window atresia does not seem to be possible according to currently reported cases. Therefore, routine examination of the round window in stapes surgery should be part of every stapes surgery and a high resolution CT scan should be considered in particular prior to revision of unsuccessful stapes surgery. As a genetic inheritance pattern can be assumed, specific emphasis should also be laid on the patient's family history.

Round window atresia and its effect on sound transmission.

OBJECTIVE: To document isolated round window atresia and to discuss its impact on current theories of inner ear function. PATIENTS AND STUDY DESIGN: Retrospective analysis of isolated round window atresia suggesting an autosomal dominant inheritance pattern and review of current concepts of cochlear macromechanics. SETTING: Tertiary referral center. RESULTS: The unexpected finding of isolated round window atresia in two female patients of the same family was confirmed intraoperatively as well as postoperatively using high-resolution computed tomography. The current audiograms and the review of the literature highlight a mixed, but predominantly conductive, hearing impairment with thresholds at 30 to 40 dB. Implying that there is no pressure release mechanism for inner ear fluid displaced by the stapes footplate, a total conductive hearing loss would be expected. CONCLUSIONS: The rare finding of round window atresia can be overlooked at surgery because of insufficient exposure of the round window niche. High-resolution computed tomography confirms the round window obliteration. It seems that an alternative way of cochlear stimulation takes place besides the concept of fluid bulk shifting. Surgery seems not to guarantee favorable results.

Isolated congenital round window absence.

Absence of the round window as a congenital defect is a rare entity that causes a conductive hearing loss. To the best of our knowledge, isolated and nonsyndromal round window absence has only been reported 3 times; the diagnoses were made during surgery. We are reporting on another case that was diagnosed before operation by virtual endoscopy of the middle ear during a high-resolution computed tomography scan. Although this new technique requires further validation, it may be an alternative to surgery as a means of confirming this rare diagnosis.

Round window atresia in association with congenital stapes fixation.

OBJECTIVE: To document an association of round window atresia with congenital stapes fixation, discuss the diagnostic role of computed tomography, and implicate the clinical significance of these anomalies. STUDY DESIGN: Retrospective chart review and review of the literature. RESULTS: The authors report three pediatric cases of round window atresia. All cases presented with hearing loss of a conductive nature (two cases bilateral, one unilateral). Two patients underwent middle ear exploration, demonstrating stapes fixation and the absence of a round window. Stapedectomy was performed in both cases without postoperative hearing improvement. Subsequent revision stapedectomy was also unsuccessful in one of these cases. The unoperated case represents the fraternal twin of one patient. In all cases, computed tomography scanning demonstrated findings consistent with atresia of the round window niche without cochlear anomaly. CONCLUSIONS: An association of round window atresia and congenital stapes fixation is apparent. The mechanism of the conductive hearing loss following stapedectomy remains poorly understood. Computed tomography imaging and surgical confirmation are probably both necessary to establish the diagnosis of round window atresia.

[High resolution computerized tomography of middle ear abnormalities]. / Hochauflösende Computer-tomographie fehlgebildeter Mittelohren.

BACKGROUND: The aim of this study was to analyze malformed petrous bones with computed tomography and to develop a radiologic score which can help to judge the indication for operative reconstructions. METHODS: One hundred forty-two petrous bones in 71 patients with unilateral or bilateral microtia, atresia of the external auditory canal, and malformations of the middle ear were evaluated with high-resolution CT. RESULTS: In 97% of patients with severe auricular dysplasia, there was dysplasia of the middle ear ossicles; in 70% the stapes was malformed. In 32% the oval window was occluded, and in 7% the round window. In 75%, the canal of the facial nerve was displaced, and 16% also showed abnormalities of the labyrinth. A close correlation between the malformation of the auricle and of the middle ear was not found. CONCLUSIONS: High-resolution CT is necessary for the evaluation of malformed middle ears. Based on the abnormalities described, we propose a radiologic score for the assessment of malformed petrous bones. This consists of the following criteria: external auditory meatus, pneumatization of the mastoid and of the tympanic space, size of the tympanic space, facial nerve, vessels, malleus and incus, stapes, oval and round window. The graded points of each structure are added up to the score, which might range between 0 and 28. This score can help to judge the indication for reconstruction of the middle ear. In bilateral malformation we suggest a middle ear reconstruction of the better hearing ear if the score is greater than or equal to 15, and in unilateral malformation if it is at least 20. In patients with lower scores, we only suggest hearing aids.

Congenital perilymphatic fistula: computed tomography appearance of middle ear and inner ear anomalies.

Congenital perilymphatic fistula is an abnormal communication between the inner ear and middle ear. Inner ear anomalies have been described on computed tomography scans. Middle ear anomalies have been found at surgery; the most frequent are anomalies of the stapes and round window. This retrospective study describes the appearance of the inner and middle ear on computed tomography scans, and of the middle ear at surgery, in 10 patients (15 ears) in whom perilymphatic fistula was found at surgery. Twelve of 15 stapes were abnormal at surgery; 4 of these 12 (33%) could be seen on computed tomography scans. Two stapes normal at surgery were normal on computed tomography. Three round windows were abnormal at surgery; none of these was seen on computed tomography scans. There were also four dysplastic cochleas, four dysplastic vestibules, and three dilated vestibular aqueducts. Computed tomography scans identified an abnormal inner ear, middle ear, or both in 8 (53%) of the 15 ears with perilymphatic fistula. An inner ear or middle ear anomaly on computed tomography may heighten clinical suspicion of congenital perilymphatic fistula.

The enlarged vestibular aqueduct syndrome (EVA syndrome).

The presentation to the Department of Pediatric Otolaryngology at the Children's Hospital of Michigan of a series of patients with sensorineural hearing loss and enlargement of the vestibular aqueduct prompted exploratory tympanotomy in three patients (two unilateral and one bilateral), for a total of four ears. These explorations were prompted by progression and/or fluctuation of hearing levels. The discovery of abnormal round windows in all four ears with a post-traumatic fistula present in one ear suggested the presence of a new association. A previously undescribed association of an enlarged vestibular aqueduct, sensorineural hearing loss and round window abnormality with potential fistula formation was identified. A review of the anatomy and physiology, literature review, and a prospective analysis with discussion of eight patients with enlarged vestibular aqueduct syndrome evaluated and treated at Children's Hospital of Michigan, is presented. We conclude that all children with sensorineural hearing loss should undergo extensive evaluation to determine etiology, including radiographic studies of the temporal bone. Further, the presence of an enlarged vestibular aqueduct should prompt the otolaryngologist to consider the presence of a round window abnormality and the potential for predisposition to perilymph fistula.

Classification of congenital middle ear anomalies. Report on 144 ears.

The surgical findings in 144 successive ears operated on for congenital conductive hearing loss were analyzed, and the results were evaluated in terms of hearing gain. All the patients underwent middle ear surgery at the University Hospital Nijmegen between 1964 and 1990. A classification system was developed to analyze the findings. Class 1 comprises ears with congenital isolated stapes ankylosis. Class 2 comprises ears with congenital stapes ankylosis in combination with a congenital anomaly of the ossicular chain. Class 3 comprises ears with congenital anomalies of the ossicular chain and at least a mobile stapes footplate. Class 4 comprises ears with aplasia or severe dysplasia of the oval window or round window.