Late pneumolabyrinth after undiagnosed post-traumatic perilymphatic fistula. Case report illustrating the importance of systematic emergency management

Temporal Bone Fractures and Related Complications in Pediatric and Adult Cranio-Facial Trauma: A Comparison of MDCT Findings in the Acute Emergency Setting

PURPOSE

The purpose of this study was to analyze the prevalence of and complications resulting from temporal bone fractures in adult and pediatric patients evaluated for cranio-facial trauma in an emergency setting.

METHODS

A retrospective blinded analysis of CT scans of a series of 294 consecutive adult and pediatric patients with cranio-facial trauma investigated in the emergency setting was conducted. Findings were compared between the two populations. Preliminary reports made by on-call residents were compared with the retrospective analysis, which was performed in consensus by two experienced readers and served as reference standard.

RESULTS

CT revealed 126 fractures in 116/294 (39.5%) patients, although fractures were clinically suspected only in 70/294 (23.8%); p < 0.05. Fractures were longitudinal, transverse and mixed in 69.5%, 10.3% and 19.8% of cases, respectively. Most fractures were otic-sparing fractures (95.2%). Involvement of the external auditory canal, ossicular chain and the osseous structures surrounding the facial nerve was present in 72.2%, 8.7% and 6.3% of cases, respectively. Temporal bone fractures extended into the venous sinuses/jugular foramen and carotid canal in 18.3% and 17.5% of cases, respectively. Vascular injuries (carotid dissection and venous thrombosis) were more common in children than in adults (13.6% versus 5.3%); however, the observed difference did not reach statistical significance. 79.5% of patients with temporal bone fractures had both brain injuries and fractures of the facial bones and cranial vault. Brain injuries were more common in adults (90.4%) than in children (63.6%), p = 0.001. Although on-call residents reliably detected temporal bone fractures (sensitivity = 92.8%), they often missed trauma-associated ossicular dislocation (sensitivity = 27.3%).

CONCLUSIONS

Temporal bone fractures and related complications are common in patients with cranio-facial trauma and need to be thoroughly looked for; the pattern of associated injuries is slightly different in children and in adults.

Postoperative Pneumolabyrinth Following the Middle Cranial Fossa Approach for Superior Semicircular Canal Dehiscence Repair, 2014-2020

OBJECTIVE

The present study investigates risk factors and clinical outcomes of postoperative pneumolabyrinth following the middle cranial fossa approach for superior semicircular canal dehiscence repair, a complication that has not been documented previously.

STUDY DESIGN

Retrospective cohort study.

SETTING

Tertiary/quaternary care referral center.

METHODS

We conducted a retrospective review of 332 middle cranial fossa procedures from 2014 to 2020 at a tertiary/quaternary care institution. Upon identifying pneumolabyrinth cases from postoperative computed tomography temporal bone scans, we conducted multivariable logistic regression analysis to explore demographic and clinical factors that were independently linked to this complication. We also compared the rates of postoperative symptoms among patients with different grades of pneumolabyrinth.

RESULTS

We identified 41 (12.3%) pneumolabyrinth cases. Patients with older age, higher preoperative pure tone average, and frank dehiscence were at higher risk for pneumolabyrinth. Furthermore, patients with pneumolabyrinth reported significantly higher rates of postoperative dizziness and exhibited significantly greater pure tone average and air-bone gap postoperatively as compared with patients without pneumolabyrinth. Finally, higher-grade pneumolabyrinth was associated with increased rates of postoperative hearing loss, and grade III pneumolabyrinth was associated with higher rates of postoperative tinnitus vs grade I and II cases.

CONCLUSION

Pneumolabyrinth following the middle cranial fossa approach was associated with poor clinical outcomes, including dizziness and auditory impairment. Old age, high preoperative pure tone average, and frank dehiscence were risk factors for this complication. The highlighted parameters may be important to note when considering this approach as a treatment option and while monitoring postoperative recovery.

Pneumolabyrinth: a systematic review

PURPOSE

The aim of this study is to provide a systematic review of the literature about the etiology, clinical and radiological presentation, surgical management, and outcomes of pneumolabyrinth (PNL).

METHODS

A systematic review of the literature was performed including studies published up to September 2020 in electronic databases (PubMed/MEDLINE, EMBASE, Cochrane Library, and Scopus). The PRISMA standard was applied to identify English, Italian, or French-language studies mentioning PNL. Full texts lacking information on the etiology were excluded. Data concerning the cause, site of air bubbles/fistula, clinical presentation, treatment, and outcome were collected. A qualitative synthesis of the results was performed.

RESULTS

Seventy-eight articles were eventually included; 132 patients were involved in the qualitative synthesis. The most common causes were: stapes surgery (24/132, 18.2%), temporal bone fracture (42/132, 31.8%), head trauma without temporal bone fracture (19/132, 14.4%), penetrating trauma (21/132, 15.9%), and barotrauma (15/132, 11.4%). The site most commonly involved was the vestibule (102/107, 95.3%), followed by cochlea (43/107, 40.2%) and semicircular canals (25/107, 23.4%).

CONCLUSION

The etiopathogenesis of PNL can be summarized in traumatic, iatrogenic, or inflammatory/infective. Its management consists in exploratory tympanotomy and sealing the fistula, but also conservative treatments can be attempted. Vestibular symptoms disappear in the majority of cases. Instead, the prognosis of hearing function is widely variable, and complete recovery is less probable. The certainty of evidence is still too low to make it useful for clinical decision-making.

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.

[Traumatic perilymphatic fistula with the luxation of the stapes into vestibule]

A case of perilymphatic fistula with the luxation of the stapes into vestibule was described, which was caused by a direct damage of the eardrum (the patient cleaned the right ear with a cotton swab and received a strong blow to the arm). The moment of injury was characterized by severe pain, a significant hearing loss, the appearance of tympanophonia and vertigo. Clinical examination revealed the eardrum rupture. After perforation healing the hearing did not improve, a high degree of mixed sensorineural hearing loss remained with a bone-air interval of up to 50 dB throughout the tone scale. CT of the temporal bones showed a pneumolabirinth and a change in the malleus position, which made it possible to suggest the presence of a perilymphatic fistula with the luxation of the stapes. The extent of damage was confirmed by surgery. The stapes was removed and the perilymphatic fistula was closed.

Traumatic Injury of the Petrous Part of the Temporal Bone: Keys for Reporting a Complex Diagnosis

Fractures of the petrous part of the temporal bone are a common lesion of the base of the skull; most of these fractures result from high-energy trauma. In patients with multiple trauma, these injuries can be detected on CT scans of the head and neck, where the direct and indirect signs are usually sufficient to establish the diagnosis. It is important to these fractures because the temporal bone has critical structures and the complexity of this region increases the risk of error unless special care is taken. This article reviews the key anatomical points, the systematization of the imaging findings, and the classifications used for temporal bone fracture. We emphasize the usefulness of identifying and describing the findings in relation to important structures in this region, of looking for unseen fractures suspected through indirect signs, and of identifying anatomical structures that can simulate fractures. We point out that the classical classifications of these fractures are less useful, although they continue to be used for treatment decisions.

The Rates and Clinical Characteristics of Pneumolabyrinth in Temporal Bone Fracture

BACKGROUND

Pneumolabyrinth is a rare inner ear clinical manifestation. To date, only about 50 cases have been reported—all as case reports. Consequently, the rate and clinical characteristics of pneumolabyrinth have not been evaluated.

METHODS

Of the 38, 568 patients who visited our emergency department for head trauma, 466 underwent temporal bone computed tomography (CT). One hundred seventy-five patients had temporal bone fracture (13 bilateral temporal bone fractures; 188 ears with temporal bone fractures), and 14 patients had pneumolabyrinth (15 ears with pneumolabyrinth; 1 bilateral case). A retrospective review of their medical records and radiologic findings was performed. Temporal bone fractures were classified by two different systems: the traditional classification and an otic capsule-based classification.

RESULTS

Pneumolabyrinth occurred in 8.0% of all temporal bone fractures, 4.0% of longitudinal temporal bone fractures, 16.1% of transverse or mixed temporal bone fractures, and 48.4% of otic capsule-violating temporal bone fractures. In all cases, pneumolabyrinth was found on CT, which was performed within 3 days, but not on follow-up CT performed 5 days or longer after head trauma. All patients complained of hearing loss and dizziness. Hearing in most patients (83.3%) did not improve, whereas dizziness improved in 91.7% of patients. Air was located only in the vestibule or semicircular canal in 53.3% and in the vestibular or semicircular canal and cochlea in 46.6% of ears with pneumolabyrinth. The initial hearing threshold and recovery rate using pure-tone audiometry were not different according to the air location in the inner ear.

CONCLUSION

Pneumolabyrinth was more common than expected; we believe that the timing of evaluation affects its rarity. Pneumolabyrinth was detected in nearly 50% of patients with otic capsule-violating temporal bone fractures when CT scanning was performed early after trauma.

Late pneumolabyrinth may be induced by old penetrating injury: possibility of undiagnosed posttraumatic perilymphatic fistula

Traumatic pneumolabyrinth is a relatively rare entity. We report the case of a unilaterally deaf woman with pneumolabyrinth who had suffered penetrating injury 15 years ago. This past history indicated that the case was late pneumolabyrinth occurring from undiagnosed old posttraumatic perilymphatic fistula. In Japan, most cases of traumatic pneumolabyrinth are caused by penetrating injury with an ear pick. Dizziness often improves within several months. Immediate surgical intervention is recommended for hearing loss, but the hearing outcome is not satisfactory. An appropriate strategy should be selected based on the interval to surgery, bone conduction hearing level at disease onset, stapes lesions, and location of air.

Intralabyrinthine penetrating ventilation tube with preservation of hearing: an unusual clinical situation

Introduction Traumatic perilymphatic fistula is not a rare event with regards to sport activities or traffic accident. However, iatrogenic damage to the inner ear can occur following the common use of grommets and ventilation tube insertion.

Objectives To report an unusual case of insertion of aeration tube into the vestibule trough the stapes footplate.

Resumed Report A 62-year-old woman experienced iatrogenic penetration into the vestibule from a ventilation tube inserted for retraction pocket management. The event was misdiagnosed both by the surgeon and by the emergency room physicians, leading to delay in the management. However, preservation of the hearing function lasted for 2 weeks prior to deafness, thanks to the valve of Bast, which preserved the cochlear fluid.

Conclusion This case gives us the opportunity to stress the need for systematic clinical examination of traumatic injury to the ear and to recommend performing multiplanar millimetric computed tomography scan with accurate interpretation. Traumatic injuries should be referred to a dedicated traumatic emergency referral center.

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.