Pathogenic mechanism analysis of cochlear key structural lesion and phonosensitive hearing loss.

Due to ethical issues and the very fine and complex structure of the cochlea, it is difficult to directly perform experimental measurement on the human cochlea. Therefore, the finite element method has become an effective and replaceable new research means. Accurate numerical analysis on human ear using finite element method can provide better understanding of sound transmission and can be used to assess the influence of diseases on hearing and to treat hearing loss. In this research, a three-dimensional (3D) finite element model (FEM) of the human ear of cochlea was presented to investigate the destruction of basilar membrane (BM), round window (RW) sclerosis and perilymph fistula, the key structures of the cochlea, and analyze the effects of these abnormal pathological states in the cochlea on cochlear hearing, resulting in the changes in cochlear sense structure biomechanical behavior and quantitative prediction of the degree and harm of the disorder to the decline of human hearing. Therefore, this paper can deepen reader's understanding of the cochlear biomechanical mechanism and provide a theoretical foundation for clinical otology.

Traumatic Stapediovestibular Dislocation With Intact Stapes: Report and Review.

Stapediovestibular dislocation is a rare disorder as a result of traumatic injury to the structures in the middle ear. We described a case of a 60-year-old female with stapediovestibular dislocation with associated perilymph fistula. She presented with symptoms including hearing loss, vertigo, and tinnitus after a penetrating injury by an ear pick. After 4 months of conservative management, her symptoms failed to improve. Therefore, she underwent surgery which resolved completely her vestibular symptoms and her hearing loss had partially improved. The restoration of the stapes to its normal anatomical position coupled with ossiculoplasty and closure of the tympanic membrane are effective in patients with stapediovestibular dislocation.

New model of superior semicircular canal dehiscence with reversible diagnostic findings characteristic of patients with the disorder.

Background: Third window syndrome is a vestibular-cochlear disorder in humans in which a third mobile window of the otic capsule creates changes to the flow of sound pressure energy through the perilymph/endolymph. The nature and location of this third mobile window can occur at many different sites (or multiple sites); however, the most common third mobile window is superior semicircular canal dehiscence (SSCD). There are two essential objective diagnostic characteristics needed to validate a model of SSCD: the creation of a pseudoconductive hearing loss and cVEMP increased amplitude and decreased threshold. Methods: Adult Mongolian gerbils (n = 36) received surgical fenestration of the superior semicircular canal of the left inner ear. ABR and c+VEMP testing were carried out prior to surgery and over acute (small 1 mm SSCD, 1-10 days) or prolonged (large 2 mm SSCD, 28 days) recovery. Because recovery of function occurred quickly, condenser brightfield stereomicroscopic examination of the dehiscence site was carried out for the small SSCD animals post-hoc and compared to both ABRs and c+VEMPs. Micro-CT analysis was also completed with representative samples of control, day 3 and 10 post-SSCD animals. Results: The SSCD created a significant worsening of hearing thresholds of the left ear; especially in the lower frequency domain (1-4 kHz). Left (EXP)/right (CTL) ear comparisons via ABR show significant worsening thresholds at the same frequency representations, which is a proxy for the human pseudoconductive hearing loss seen in SSCD. For the c+VEMP measurements, increased amplitude of the sound-induced response (N1 2.5 ms and P1 3.2 ms) was observed in animals that received larger fenestrations. As the bone regrew, the c+VEMP and ABR responses returned toward preoperative values. For small SSCD animals, micro-CT data show that progressive osteoneogenesis results in resurfacing of the SSCD without bony obliteration. Conclusion: The large (2 mm) SSCD used in our gerbil model results in similar electrophysiologic findings observed in patients with SSCD. The changes observed also reverse and return to baseline as the SSCD heals by bone resurfacing (with the lumen intact). Hence, this model does not require a second surgical procedure to plug the SSCD.

[Does sealing the oval window in addition to the round window bring an advantage in reserve therapy of acute idiopathic deafness?] / Bringt die Abdeckung des ovalen Fensters zusätzlich zum runden Fenster bei der Reservetherapie der akuten idiopathischen Ertaubung einen Vorteil?

BACKGROUND: Following sudden unilateral deafness or severe sensorineural hearing loss, patients with unsuccessful intravenous steroid therapy can be treated with explorative tympanotomy with sealing of the round (RW) and/or oval window (OW), due to suspected rupture of the RW with perilymph fistula (PLF) or a fissula ante fenestram (FAF). This study investigated whether additional sealing of the oval window (RW+OW) achieved an improved hearing benefit as compared to sealing of the round window only (RW) . METHODS: This retrospective study investigated 54 patients with acute profound hearing loss who underwent tympanoscopy. Audiometric examinations were performed preoperatively and at two postoperative intervals (1 month and 3-6 months after surgery). In 28 patients, the OW was sealed in addition to the RW. RESULTS: No intraoperatively visible PLF or FAF were reported. Hearing thresholds were significantly reduced in the early postoperative follow-up period and further improvement was observed 3-6 months later. No significant differences between the RW and RW+OW subgroups were seen at either follow-up timepoint. In 65% (Kanzaki criteria) and 74% (Siegel criteria) of patients, partial or complete postoperative hearing improvement was observed. Upon comparing the groups of patients with and without hearing improvement, no statistical significance was found in terms of gender, age, secondary diagnoses, or latency period between symptom onset and surgery. CONCLUSION: Additional sealing of the OW did not lead to significantly better postoperative hearing thresholds. In general, postoperative hearing improvement corresponds to published spontaneous remission rates.

Congenital Membranous Stapes Footplate Producing Episodic Pressure-Induced Perilymphatic Fistula Symptoms.

Introduction: Recent third window syndrome studies have revealed that the intact bony labyrinth and differences in the stiffness of the oval and round windows are essential for proper cochlear and vestibular function. Herein we report a patient with a congenital dehiscence of the right stapes footplate. This dehiscence caused long-standing episodic pressure-induced vertigo (Hennebert sign). At the time of presentation, her increased thoracic pressure changes induced the rupture of the membranous stapes footplate. Perilymph leakage was confirmed by imaging and a biochemical test [perilymph-specific protein Cochlin-tomoprotein (CTP) detection test]. Case Report: A 32-year-old woman presented with a sudden onset of right-sided hearing loss and severe true rotational vertigo, which occurred immediately after nose-blowing. CT scan showed a vestibule pneumolabyrinth. Perilymphatic fistula (PLF) repair surgery was performed. During the operation, a bony defect of 0.5 mm at the center of the right stapes footplate, which was covered by a membranous tissue, and a tear was found in this anomalous membrane. A perilymph-specific protein CTP detection test was positive. The fistula in the footplate was sealed. Postoperatively, the vestibular symptoms resolved, and her hearing improved. A more detailed history revealed that, for 15 years, she experienced true rotational vertigo when she would blow her nose. After she stopped blowing her nose, she would again feel normal. Discussion: There is a spectrum of anomalies that can occur in the middle ear, including the ossicles. The present case had a dehiscence of the stapes, with a small membranous layer of tissue covering a bony defect in the center of the footplate. Before her acute presentation to the hospital, this abnormal footplate with dehiscence induced pathological pressure-evoked fluid-mechanical waves in the inner ear, which resulted in Hennebert sign. When patients have susceptibility (e.g., weak structure) to rupture, such as that identified in this case, PLF can be caused by seemingly insignificant events such as nose-blowing, coughing, or straining. Conclusion: This case demonstrates that PLF is a real clinical entity. Appropriate recognition and treatment of PLF can improve a patient's condition and, hence, the quality of life.

Perilymphatic Fistula: A Review of Classification, Etiology, Diagnosis, and Treatment.

A perilymphatic fistula (PLF) is an abnormal communication between the perilymph-filled inner ear and the middle ear cavity, mastoid, or intracranial cavity. A PLF most commonly forms when the integrity of the oval or round window is compromised, and it may be trauma-induced or may occur with no known cause (idiopathic). Controversy regarding the diagnosis of idiopathic PLF has persisted for decades, and the presenting symptoms may be vague. However, potential exists for this condition to be one of the few etiologies of dizziness, tinnitus, and hearing loss that can be treated surgically. The aim of this review is to provide an update on classification, diagnosis, and treatment of PLF. Particular attention will be paid to idiopathic PLF and conditions that may have a similar presentation, with subsequent information on how best to distinguish them. Novel diagnostic criteria for PLF and management strategy for PLF and PLF-like symptoms is presented.

Membranous or Hypermobile Stapes Footplate: A New Anatomic Site Resulting in Third Window Syndrome.

Objectives: To describe a potentially underappreciated pathology for post-traumatic persistent intractable dizziness and third window syndrome as well as the methods to diagnose and surgically manage this disorder. Study Design: Observational analytic case studies review at a tertiary care medical center. Methods: Patients suffering persistent dizziness following head trauma and demonstrating Tullio phenomena or Hennebert signs are included. All had reportedly normal otic capsules on high resolution temporal bone CT scans (CT). The gray-scale invert function was used to visualize the stapes footplate, which helped determine the diagnosis. Gray-scale inversion can be used to improve visualization of temporal bone anatomy and pathologic changes when diagnoses are in doubt. A search to check for the presence of perilymph leakage was performed in all cases. This was accomplished using intraoperative Valsalva maneuvers. Fat grafting of round and oval windows was performed. Results: Over an 11-year period between January 2009 and December 2019, 28 patients (33 ears) were treated. Follow-up with balance testing and audiograms were performed 6-8 weeks following surgery. Follow-up ranged from 6 months to 7 years. Prior to surgery all patients reported dizziness in response to loud sounds and/or barometric pressure changes. Seven out of 33 ears had demonstrable perilymph leakage into the middle ear; the rest (26 ears) appeared to have membranous or hypermobile stapes footplates. Membranous stapes footplates were better visualized using the invert function on CT. Thirteen patients had a fistula sign positive bilaterally while 15 had unilateral pathology. Twenty-four of the 28 patients (85.7%) showed both subjective and objective improvement following surgery. No patients suffered from a deterioration in hearing. Conclusions: A previously underappreciated membranous or hypermobile stapes footplate can occur following head trauma and can cause intractable dizziness typical of third window syndrome (TWS). Durable long term success can be achieved by utilizing fat graft patching of the round and oval windows. High resolution temporal bone CT scans using the gray-scale inversion (invert) function can assist in preoperative diagnosis.

Third Window Syndrome: Surgical Management of Cochlea-Facial Nerve Dehiscence.

Objective: This communication is the first assessment of outcomes after surgical repair of cochlea-facial nerve dehiscence (CFD) in a series of patients. Pre- and post-operative quantitative measurement of validated survey instruments, symptoms, diagnostic findings and anonymous video descriptions of symptoms in a cohort of 16 patients with CFD and third window syndrome (TWS) symptoms were systematically studied. Study design: Observational analytic case-control study. Setting: Quaternary referral center. Patients: Group 1 had 8 patients (5 children and 3 adults) with CFD and TWS who underwent surgical management using a previously described round window reinforcement technique. Group 2 had 8 patients (2 children and 6 adults) with CFD who did not have surgical intervention. Interventions: The Dizziness Handicap Inventory (DHI) and Headache Impact Test (HIT-6) were administered pre-operatively and post-operatively. In addition, diagnostic findings of comprehensive audiometry, cervical vestibular evoked myogenic potential (cVEMP) thresholds and electrocochleography (ECoG) were studied. Symptoms before and after surgical intervention were compared. Main outcome measures: Pre- vs. post-operative DHI, HIT-6, and audiometric data were compared statistically. The thresholds and amplitudes for cVEMP in symptomatic ears, ears with cochlea-facial nerve dehiscence and ears without CFD were compared statistically. Results: There was a highly significant improvement in DHI and HIT-6 at pre- vs. post-operative (p < 0.0001 and p < 0.001, respectively). The age range was 12.8-52.9 years at the time of surgery (mean = 24.7 years). There were 6 females and 2 males. All 8 had a history of trauma before the onset of their symptoms. The mean cVEMP threshold was 75 dB nHL (SD 3.8) for the operated ear and 85.7 dB (SD 10.6) for the unoperated ear. In contrast to superior semicircular canal dehiscence, where most ears have abnormal ECoG findings suggestive of endolymphatic hydrops, only 1 of 8 operated CFD ears (1 of 16 ears) had an abnormal ECoG study. Conclusions: Overall there was a marked improvement in DHI, HIT-6 and symptoms post-operatively. Statistically significant reduction in cVEMP thresholds was observed in patients with radiographic evidence of CFD. Surgical management with round window reinforcement in patients with CFD was associated with improved symptoms and outcomes measures.

Comorbidities confounding the outcomes of surgery for third window syndrome: Outlier analysis.

Objective: Patients with third window syndrome and superior semicircular canal dehiscence (SSCD) symptoms whose surgical outcomes placed them as outliers were systematically studied to determine comorbidities that were responsible for their poor outcomes due to these confounding factors. Study Design: Observational analytic case-control study in a tertiary referral center. Methods: Twelve adult patients with clinical SSCD syndrome underwent surgical management and had outcomes that did not resolve all of their subjective symptoms. In addition to one of the neurotologists, 2 neurologists (one specializing in migraine and the other a neuro-ophthalmologist), and a psychologist clinician-investigator completed comprehensive evaluations. Neuropsychology test batteries included: the Millon Behavioral Medicine Diagnostic; Patient Health Questionnaire (PHQ-9) and Generalized Anxiety Disorder Screener (GAD-7); Adverse Childhood Experiences Scale; the Wide Range Assessment of Memory and Learning, including the 3 domains of verbal memory, visual memory, and attention/concentration; Wechsler Adult Intelligence Scale; and the Delis-Kaplan Executive Function System. The control cohort was comprised of 17 participants who previously underwent surgery for third window syndrome that resulted in the expected outcomes of resolution of their third window syndrome symptoms and cognitive dysfunction. Results: There was a high rate of psychological comorbidity (n = 6) in the outlier cohort; multiple traumatic brain injuries were also a confounding element (n = 10). One patient had elevated cerebrospinal fluid (CSF) pressure requiring ventriculoperitoneal shunting to control the recurrence of dehiscence and one patient with a drug-induced Parkinson-like syndrome and idiopathic progressive neurological degenerative process. Conclusions: Components of the Millon Behavioral Medicine Diagnostic, PHQ-9 and GAD-7 results suggest that these instruments would be useful as screening tools preoperatively to identify psychological comorbidities that could confound outcomes. The identification of these comorbid psychological as well as other neurological degenerative disease processes led to alternate clinical management pathways for these patients. Level of Evidence: 2b.

The Clinical Uses of Electrocochleography.

The clinical uses of electrocochleography are reviewed with some technical notes on the apparatus needed to get clear recordings under different conditions. Electrocochleography can be used to estimate auditory thresholds in difficult to test children and a golf club electrode is described. The same electrode can be used to obtain electrical auditory brainstem responses (EABR). Diagnostic testing in the clinic can be performed with a transtympanic needle electrode, and a suitable disposable monopolar electrode is described. The use of tone bursts rather than click stimuli gives a better means of diagnosis of the presence of endolymphatic hydrops. Electrocochleography can be used to monitor the cochlear function during surgery and a long coaxial cable, which can be sterilized, is needed to avoid electrical artifacts. Recently electrocochleography has been used to monitor cochlear implant insertion and to record residual hearing using an electrode on the cochlear implant array as the non-inverting (active) electrode.

Diagnostic criteria of barotraumatic perilymph fistula based on clinical manifestations.

CONCLUSIONS: Patients with sudden hearing loss and dizziness after barotrauma should be suspected of barotraumatic perilymph fistula (PLF). Early surgical repair of PLF showed better hearing outcomes. Therefore, diagnostic criteria should help surgical indications of barotraumatic PLF. OBJECTIVES: The aim of this study was to establish diagnostic criteria for barotraumatic PLF. METHODS: Twenty-four patients (26 ears) underwent surgery on suspicion of barotraumatic PLF. The causes of barotrauma and clinical symptoms were analyzed by surgical findings. Diagnostic criteria of PLF were proposed according to its clinical manifestations. RESULTS: Definite PLF (17 subjects) was confirmed by any evidence of perilymph leak through oval and round windows. For the other seven subjects (probable PLF), even though there was no evidence of perilymph leak, their clinical manifestations were similar to definite PLF. High frequency hearing loss occurred as an early symptom after barotrauma. Positional dizziness occurred a few hours after auditory symptoms (67%). Positional nystagmus was observed in 10 cases. The characteristics of positional nystagmus were multi-directional, longer in duration, smaller in amplitude, no reversibility, and no response to repositioning maneuver. Regarding the surgical outcomes, hearing was significantly improved in the early repaired PFL group, and dizziness was improved in 96% of patients.

Cochlin-tomoprotein test and hearing outcomes in surgically treated true idiopathic perilymph fistula.

CONCLUSION: Approximately 50% of patients with sPLF based on the clinical diagnosis criteria were definitively diagnosed with CTP-positive sPLF. These results suggest that early surgery within 7 days of the disease onset contributes to improvements in the therapeutic response of hearing loss. OBJECTIVES/HYPOTHESIS: Idiopathic spontaneous perilymph fistula (sPLF) cannot be diagnosed reliably. It is speculated that this condition occurs in patients with vertigo-accompanied acute sensorineural hearing loss that progresses rapidly in spite of steroid therapy. This study herein evaluated cochlin-tomoprotein (CTP) test results in patients with sPLF who underwent exploratory tympanotomy and considered surgical outcomes with true sPLF. STUDY DESIGN: Retrospective study. METHODS: Twenty-three patients diagnosed with sPLF based on the clinical diagnosis criteria who underwent exploratory tympanotomy were included. RESULTS: CTP test results were positive in 11 cases. In CTP-positive cases, the mean hearing level was 66.5 dB pre-operatively and 42.3 dB post-operatively. The hearing level post-operatively completely recovered in four cases, markedly recovered in three cases, slightly recovered in one case and showed no response in three cases. Hearing level improvements were significantly better in CTP-positive patients who underwent surgery within 7 days of the disease onset than in those treated 8 or more days after the disease onset.

A case of intractable suspected perilymph fistula with severe depression.

A 68-year-old woman presented dizziness whenever she put her finger into the right ear and also complained of water-streaming tinnitus, which indicated she would have been suffering from perilymph fistula. An exploratory tympanotomy was conducted. Leakage of perilymph from the round window was suspected, although the cochlin-tomoprotein (CTP) results were negative. After the procedure, the patient's finger-induced dizziness, tinnitus, and vertigo spells disappeared completely. However, her dizzy symptom did not improve. The patient also complained of general fatigue, weight loss, and insomnia, which led us to suspect comorbid depression. Antidepressants and vestibular rehabilitation treatment resulted in a significant improvement in her dizziness. Although it is not apparent whether the patient had a perilymph fistula, this case demonstrates the importance of evaluating not only physical symptoms but also psychological comorbidity, especially when the physical symptoms are intractable despite treatment.

A Case of Intractable Suspected Perilymph Fistula with Severe Depression

A 68-year-old woman presented dizziness whenever she put her finger into the right ear and also complained of water-streaming tinnitus, which indicated she would have been suffering from perilymph fistula. An exploratory tympanotomy was conducted. Leakage of perilymph from the round window was suspected, although the cochlin-tomoprotein (CTP) results were negative. After the procedure, the patient's finger-induced dizziness, tinnitus, and vertigo spells disappeared completely. However, her dizzy symptom did not improve. The patient also complained of general fatigue, weight loss, and insomnia, which led us to suspect comorbid depression. Antidepressants and vestibular rehabilitation treatment resulted in a significant improvement in her dizziness. Although it is not apparent whether the patient had a perilymph fistula, this case demonstrates the importance of evaluating not only physical symptoms but also psychological comorbidity, especially when the physical symptoms are intractable despite treatment.

Superior Semicircular Canal Dehiscence Syndrome Presenting with Sudden Deafness and Vertigo after Trauma / 대한평형의학회지

Superior semicircular canal dehiscence syndrome (SCDS) is characterized by cochleovestibular hyper-responsiveness symptoms including sound- and pressure-evoked vertigo and oscillopsia, autophony, hyperacusis and ear fullness. The typical audiometric feature of SCDS is known as conductive hearing loss at low frequency. A 43-year-old man presented with unilateral sudden deafness after several events of heading during soccer game. High-resolution temporal bone computed tomography revealed a dehiscence of superior canal encased by superior petrous sinus. We reviewed audio-vestibular findings in this patient and speculated potential pathogenic mechanisms of sudden deafness in SCDS with literature review.

Effects of early surgical exploration in suspected barotraumatic perilymph fistulas.

OBJECTIVES: Treatment of traumatic perilymph fistula (PLF) remains controversial between surgical repair and conservative therapy. The aim of this study is to analyze the outcomes of early surgical exploration in suspected barotraumatic PLF. METHODS: Nine patients (10 cases) who developed sudden sensorineural hearing loss and dizziness following barotrauma and underwent surgical exploration with the clinical impression of PLF were enrolled. Types of antecedent trauma, operative findings, control of dizziness after surgery, postoperative hearing outcomes, and relations to the time interval between traumatic event and surgery were assessed retrospectively. RESULTS: All patients had sudden or progressive hearing loss and dizziness following trauma. Types of barotrauma were classified by the origin of the trauma: 4 external (car accident, slap injury) and 6 internal traumas (lifting, nasal blowing, straining). Surgical exploration was performed whenever PLF was suspected with the time interval of 2 to 47 days after the trauma. The possible evidence of PLF was found during surgery in 9 cases: a fibrous web around the oval window (n=3), fluid collection in the round window (RW; n=6) and bulging of the RW pseudomembrane (n=1). In every patient, vestibular symptoms disappeared immediately after surgery. The hearing was improved with a mean gain of 27.0±14.9 dB. When the surgical exploration was performed as early as less than 10 days after the trauma, serviceable hearing (≤40 dB) was obtained in 4 out of 7 cases (57.1%). CONCLUSION: Sudden or progressive sensorineural hearing loss accompanied by dizziness following barotrauma should prompt consideration of PLF. Early surgical exploration is recommended to improve hearing and vestibular symptoms.

Effects of Early Surgical Exploration in Suspected Barotraumatic Perilymph Fistulas

OBJECTIVES: Treatment of traumatic perilymph fistula (PLF) remains controversial between surgical repair and conservative therapy. The aim of this study is to analyze the outcomes of early surgical exploration in suspected barotraumatic PLF. METHODS: Nine patients (10 cases) who developed sudden sensorineural hearing loss and dizziness following barotrauma and underwent surgical exploration with the clinical impression of PLF were enrolled. Types of antecedent trauma, operative findings, control of dizziness after surgery, postoperative hearing outcomes, and relations to the time interval between traumatic event and surgery were assessed retrospectively. RESULTS: All patients had sudden or progressive hearing loss and dizziness following trauma. Types of barotrauma were classified by the origin of the trauma: 4 external (car accident, slap injury) and 6 internal traumas (lifting, nasal blowing, straining). Surgical exploration was performed whenever PLF was suspected with the time interval of 2 to 47 days after the trauma. The possible evidence of PLF was found during surgery in 9 cases: a fibrous web around the oval window (n=3), fluid collection in the round window (RW; n=6) and bulging of the RW pseudomembrane (n=1). In every patient, vestibular symptoms disappeared immediately after surgery. The hearing was improved with a mean gain of 27.0+/-14.9 dB. When the surgical exploration was performed as early as less than 10 days after the trauma, serviceable hearing (< or =40 dB) was obtained in 4 out of 7 cases (57.1%). CONCLUSION: Sudden or progressive sensorineural hearing loss accompanied by dizziness following barotrauma should prompt consideration of PLF. Early surgical exploration is recommended to improve hearing and vestibular symptoms.

Transtympanic Endoscopic Diagnosis of Perilymph Fistula / 대한이비인후과학회지

Perilymph fistula (PLF) is a disease for which diagnostic criteria have not been established yet. For this reason, at the present time, the definitive diagnosis of PIS can only be made by direct identification of perilymphatic leak during exploratory tympanotomy. But it can be difficult to distinguish between serous transudates from operative incisions and the clear fluid expected with a true fistula. Infiltrated lidocaine makes the distinction even more difficult as well. Recently, endoscopies have been used in middle ear by transtympanic or transtubal approach. However, endoscopic diagnosis of PLF in the literature is very rare. We diagnosed 2 cases of PLF by transtympanic endoscopy. Because transtympanic endoscopy did not require lidocaine infiltration nor performing a tympanomeatal flap, confirmation of perilymphatic leakage was easier. This study therefore recommends transtympanic endoscopy as one method of improving diagnosis of PLF.