Perilymph fistula--45 case analysis

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.

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.

Detection of perilymphatic fistula in labyrinthine windows by virtual endoscopy and variation of reconstruction thresholds on CT scan

Background: Perilymphatic fistula (PLF) is a breach in a labyrinthine window. The opening might decrease the radiological density of the window.Aims/objectives: To evaluate the radiological density of the labyrinthine windows by virtual endoscopy on CT scan.Materials and methods: This prospective study included 47 adult patients with PLF and 98 control patients. Diagnosis of PLF was based on a composite radio clinical score and/or intra operative visualization of the fistula and/or resolution of the symptoms after surgery. On routine CT-scan, labyrinthine windows were examined by virtual endoscopy. The reconstruction threshold was gradually increased until a virtual opening appeared (opening threshold [OT]) and compared to the contralateral window (OT difference).Results: The OT difference was higher in patients than in controls (60.2 ± 10.36 (SEM), n = 47 versus 28.0 ± 2.29 Hounsfield units (HUs), n = 98, p < .01 unpaired t-test). A ROC analysis showed that at an OT difference of 31.5 UH had a sensitivity of 75% and a specificity of 75% for the PLF diagnosis.Conclusions: CT-scan virtual endoscopy and threshold variation provided high specificity and sensitivity in the PLF diagnosis.Significance: This post processing of radiological data appears to enhance the diagnostic value of CT scan.

The ineffectiveness of applying moisture to the ear on the incidence and severity of otic barotrauma for air passengers

OBJECTIVE

The application of moisture to the ear is anecdotally claimed to relieve the pain from otic barotrauma that can arise during aircraft descent. This claim was tested in a randomised double-blind study on an aircraft with eight participants heavily predisposed to barotrauma.

METHODS

On the outward flight, half the participants wore 'active' devices that applied moisture to the external ear; the remainder wore placebo devices that contained no moisture, but were otherwise identical. On the return flight, the groups were reversed. Participants wore the devices from just before descent until landing, unless they experienced symptoms of barotrauma, in which case they switched to what they knew was an active device.

RESULTS

There were no significant differences between conditions regarding the appearance of the tympanic membrane on landing or the discomfort levels immediately before and after any switch.

CONCLUSION

Applying moisture is ineffective for passengers heavily predisposed to otic barotrauma.

Case of perilymphatic fistula caused by medially displaced tympanostomy tube

Objective:

We present a rare case of perilymphatic fistula which occurred due to bony erosion by a tympanostomy tube that had migrated into and become interred in the middle-ear space.

Method:

We present a case report and a literature review concerning migration of tympanostomy tubes into the middle ear as a complication of tubes insertion.

Conclusion:

Medial migration of tympanostomy tubes into the middle-ear space is a rare complication of tympanostomy tubes insertion. To our knowledge, this is the first report of perilymphatic fistula caused by a tympanostomy tube which had migrated into the middle ear. This case highlights the need for early removal of tympanostomy tubes which migrate into the middle ear.

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.

Post-traumatic balance disorder

The causes of balance disorder are many and various, and the subjective syndrome of cranial trauma patients is diagnosed by elimination. Progress in otoneurologic functional exploration and brain imaging, however, now generally allow this functional complaint to be given an objective basis. In recent years, new diagnoses have improved recognition of such pathologies in the appraisal of corporal injury for compensation purposes. The present article seeks to detail etiology and, by a review of the literature, to determine factors liable to influence management and appraisal in particular.

Perilymphatic fistula of the round window after whiplash injury: another cause of inner ear conductive hearing loss

Perilymphatic fistula is usually associated with sudden or fluctuating sensorineural hearing loss. We present a case of whiplash injury in a patient who showed conductive hearing loss at low frequencies due to a perilymphatic fistula occurring in the round window. Although no middle ear pathology was found, the symptoms and laboratory findings were mimicking the so called "third mobile window" phenomenon, but without the presence of inner ear dehiscence. Following early surgical exploration with patching of the round window the hearing was restored and the patient was free of symptoms.

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.

Perilymph fistula presenting with contralateral symptoms

OUTCOME OBJECTIVES

To report the case of a contralateral Tullio phenomenon, suggest possible pathophysiology, and give insight into normal vestibular physiology.

PATIENTS

Twenty-year-old female subject who presented with 8-month symptoms of left-sided Tullio phenomenon after a motor vehicle collision. Testing suggested a right perilymphatic fistula.

INTERVENTION(S)

Bedrest and a right perilymphatic fistula repair.

MAIN OUTCOME MEASURE(S)

Cervical vestibular evoked myogenic potentials (cVEMPs), audiometry, and patient symptoms.

RESULTS

Postoperatively, the patient's symptoms of left-sided Tullio phenomenon abruptly abated, and the patient reported no activity limitations. Vertigo and phonodynia could not be reproduced. Postoperative VEMP demonstrated marked normalization (from abnormally decreased right-sided threshold and increased amplitude preoperatively). The left continued to demonstrate no abnormalities on audiogram, tympanogram, or VEMP.

CONCLUSION

This is the first known report of symptoms presenting contralateral to the side of perilymph fistula and represents a window of understanding to vestibular physiology. The cause of this unique finding may rest in the failure of commissural inhibition after labyrinth dysfunction. Clinicians should maintain heightened awareness for the possibility of inner ear dysfunction contralateral to 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 (≤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 a perilymphatic fistula on the passive vibration response of the basilar membrane

In this study, a three-dimensional finite-element model of the passive human cochlea was created. Dynamic behavior of the basilar membrane caused by the vibration of the stapes footplate was analyzed considering a fluid-structure interaction with the cochlear fluid. Next, the effects of a perilymphatic fistula (PLF) on the vibration of the cochlea were examined by making a small hole on the wall of the cochlea model. Even if a PLF existed in the scala vestibuli, a traveling wave was generated on the basilar membrane. When a PLF existed at the basal end of the cochlea, the shape of the traveling wave envelope showed no remarkable change, but the maximum amplitude became smaller at the entire frequency range from 0.5 to 5kHz and decreased with decreasing frequency. In contrast, when a PLF existed at the second turn of the cochlea, the traveling wave envelope showed a notch at the position of the PLF and the maximum amplitude also became smaller. This model assists in elucidating the mechanisms of hearing loss due to a PLF from the view of dynamics.

Perilymphatic fistula of the round window

OBJECTIVE

To highlight diagnostic and treatment pitfalls in perilymphatic fistula.

CASE REPORTS

Two cases of round-window fistula are reported, detailing clinical aspect, treatment and outcome. The triad comprising sensorineural hearing loss, tinnitus and vertigo with associated fistula sign is classical but in fact rarely encountered. Imaging is of limited contribution, but may reveal anatomic abnormalities suggestive of perilymphatic fistula. Outcome is improved by early management, especially in case of moderate hearing loss.

DISCUSSION/CONCLUSION

Diagnosis of perilymphatic fistula is challenging, but enables effective treatment. On any suspicion, surgical exploration should be undertaken, being the only reliable guide to diagnosis and etiologically adapted management.

[Perilymphatic fistula: diagnosis and treatment]

INTRODUCTION

Diagnosis and management of perilymphatic fistula (PLF) is a controversial topic in the international neurotologic literature. An illustrative case of post traumatic PLF with clear surgical indications is presented. This manuscript also reviews the various clinical presentations, pathogenesis, diagnostic examinations, and management options of PLF.

MATERIALS AND METHODS

Case report and literature review.

RESULTS

A 40 y/o female presented with paroxysmal vertigo, imbalance and severe sensorineural hearing loss (SNHL) following minor occipital head trauma from a fall six months prior to presentation. Laboratory examination included intermittently positive fistula sign on video-nystagmography. Patient failed to respond to trials of pharmacologic treatment and bedrest and ultimately underwent surgical exploration and repair. Patient had earlobe fat placed in the round and oval windows. Postoperatively, she had prompt resolution of vestibulopathy and ultimate full return of sensorineural function.

CONCLUSIONS

Patients with appropriate antecedent history demonstrating fluctuating SNHL and vestibulopathy, failing to respond to conservative medical treatments, should be considered for exploratory tympanotomy. In the absence of any other violations of labyrinthine integrity, connective tissue grafting of the round and oval windows should be performed even if no obvious flow of fluid is observed. This management protocol is safe and effective in properly selected patients.

[Exploratory tympanotomy for suspected traumatic perilymphatic fistula]

Firstly reported after stapedectomy, perilymph fistula (PLF), may occur due to trauma.

AIM

Preoperative symptoms and therapeutic results are described and analyzed after exploratory tympanotomy for traumatic PLF.

MATERIAL AND METHODS

Traumatic PLF was investigated in 90 patients (97 examinations) by exploratory tympanotomy at the Nantes University Hospital from 1995 to 1999. Preoperative symptoms were recorded and compared to results of tympanotomy to determine their diagnostic value. Similarly post-operative recovery was compared to results of tympanotomy.

RESULTS

This study showed the value of two symptoms: aural fullness and balance disturbance. During each surgical procedure, systematic grafting was performed even if fistulization was unapparent. The best results were achieved for vestibular symptoms and concerned more vertigo than auditory symptoms. There was no significant difference in postoperative symptoms, between patients with a leak and patients without a leak.

CONCLUSION

This demonstrates that the oval and round window should be grafted with connective tissue when an exploratory tympanotomy is performed.