Testosterone treatment restores vestibular function by enhancing neuronal survival in an experimental closed-head repetitive mild traumatic brain injury model.

Repetitive mild traumatic brain injury (rmTBI) results in a myriad of symptoms, including vestibular impairment. The mechanisms underlying vestibular dysfunction in rmTBI patients remain poorly understood. Concomitantly, acute hypogonadism occurs following TBI and can persist chronically in many patients. Using a repetitive mild closed-head animal model of TBI, the role of testosterone on vestibular function was tested. Male Long Evans Hooded rats were randomly divided into sham or rmTBI groups. Significant vestibular deficits were observed both acutely and chronically in the rmTBI groups. Systemic testosterone was administered after the development of chronic vestibular dysfunction. rmTBI animals given testosterone showed improved vestibular function that was sustained for 175 days post-rmTBI. Significant vestibular neuronal cell loss was, however, observed in the rmTBI animals compared to Sham animals at 175 days post-rmTBI and testosterone treatment significantly improved vestibular neuronal survival. Taken together, these data demonstrate a critical restorative role of testosterone in vestibular function following rmTBI. This study has important clinical implications because it identifies testosterone treatment as a viable therapeutic strategy for the long-term recovery of vestibular function following TBI.

An institutional review of recurrent pleomorphic adenoma of the parotid gland.

OBJECTIVE: Surgical resection is standard treatment for pleomorphic adenoma (PA) of the parotid gland. A small number (2-5%) of these tumors recur. Recurrence usually necessitates reoperation, which is technically challenging and puts the facial nerve (FN) at risk. The aim of this study is to characterize the recurrent parotid PA population and compare outcomes after surgery for singly recurrent and multiply recurrent tumors. METHODS: This study was a retrospective chart review of patients at a single tertiary care academic medical center who underwent operations for recurrent PA of the parotid gland between 2007 and 2020. Demographic data, details of surgical interventions, pre- and postoperative FN function, and recurrence rates were studied. These factors were compared between patients with singly and multiply recurrent tumors. RESULTS: Thirty-eight patients met criteria: 4 patients presented for primary PA and subsequently recurred, 26 with a first recurrence, 7 with a second recurrence, and 1 with a fourth recurrence. Multiply recurrent PAs were more likely to require at least partial nerve sacrifice at the time of reoperation (P = 0.0092). Significantly worse long-term FN outcomes were seen following surgery for multiply recurrent PA (P = 0.008). There was no significant difference between the rate of re-recurrence following first revision surgery vs second-fourth revision surgery. Time to reoperation was significantly shorter between the first and second revision surgery than between the primary surgery and first revision (P = 0.0017). CONCLUSION: Surgery for recurrent PA incurs high risk to the FN, and this risk appears to increase in the setting of multiple recurrences.

Fetal Bovine Collagen Grafts for Repair of Tegmen Defects and Encephaloceles Via Middle Cranial Fossa Approach.

To evaluate the use of commercially available allogenic dural graft materials made of fetal bovine collagen, we present an analysis of our case series with use of autologous and allogenic graft materials. Patients who underwent surgical repair of a tegmen tympani defect associated with ipsilateral conductive hearing loss and cerebrospinal fluid (CSF) otorrhea using a middle cranial fossa (MCF) approach from 2004 to 2018 at Loyola University Medical Center were included. Resolution of CSF otorrhea, audiologic outcomes, facial nerve preservation, and surgical complications was analyzed. Thirty-three patients with an average age of 55.3 years (range: 21-78, standard deviation [SD]: 12.9) and body mass index of 34.4 (range: 22-51, SD: 7.4) underwent an MCF repair of a tegmen and dural defect. All patients presented with CSF otorrhea and conductive hearing loss ipsilateral to the defect. Repairs were made with combinations of allograft and autograft in 17 cases, allograft only in 15 cases, and autograft only in 5 cases. Improvement in hearing was noted in 33 cases, and resolution of CSF otorrhea was noted in 36 cases; one patient required repeat surgery which resolved CSF otorrhea. Three patients had minor complications; all these were in the autograft group. The MCF approach coupled with the use of fetal bovine collagen grafts is a safe and viable method to repair tegmen tympani and associated dural defects with salutary outcomes and low morbidity.

Glomus faciale tumors: A report of 3 cases and literature review.

Our objectives in reporting this case series are to familiarize readers with the rare occurrence of paragangliomas originating along the facial nerve and to provide a literature review. We describe 3 such cases that occurred at our tertiary care academic medical center. Two women and 1 man presented with a tumor adjacent to the vertical segment of the facial nerve. The first patient, a 48-year-old woman, presented with what appeared to be a parotid tumor at the stylomastoid foramen; she underwent a parotidectomy, transmastoid facial nerve decompression, and a shave biopsy of the tumor. The second patient, a 66-year-old man, underwent surgery via a postauricular infratemporal fossa approach, and a complete tumor resection was achieved. The third patient, a 56-year-old woman, presented with a middle ear mass; she underwent complete tumor removal through a transmastoid transcanal approach. All 3 patients exhibited normal facial nerve function both before and after surgery. Paragangliomas of the facial nerve are extremely rare, and their signs and symptoms are unlike those of any other temporal bone glomus tumors. Management options include surgical resection, radiologic surveillance, and radiotherapy. The facial nerve can be spared in selected cases.

Auricular complications in parotid, temporal bone, infratemporal fossa, and lateral skull base surgery.

Neoplasms located in the parotid region, temporal bone, infratemporal fossa, and lateral skull base represent a challenge due to their difficult anatomic location and surrounding neurovascular structures. A variety of surgical approaches are appropriate to access this area, although several of them can place the auricular blood supply in danger. If the auricular blood supply is compromised, ischemia and, eventually, avascular necrosis of the auricle can occur. Auricular necrosis often can cause patients a delay in adjuvant radiation therapy and result in the need for additional reconstructive procedures. Therefore, it is imperative to identify risk factors associated with the development of this disabling complication. We conducted a retrospective review of 32 individuals undergoing treatment of benign and malignant lesions in the parotid gland, infratemporal fossa, and lateral skull base. To identify potential risk factors for auricular necrosis, the patients were analyzed based on the type of neoplasm (malignant or benign), risk factors affecting blood flow (diabetes mellitus, smoking history, prior radiation, prior surgery), body mass index, and the length of surgery. In our population examined, 3 instances of auricular necrosis occurred. None of the potential risk factors proved to be statistically significant (although malignant pathology approached significance at p = 0.07). Two of the patients required an auriculectomy with reconstruction. The third had multiple postoperative clinic visits for surgical debridement. Although no potential risk factors were statistically significant, surgeons should remain cognizant of the auricular blood supply while performing surgery via preauricular and postauricular approaches to this area.

Facial reanimation according to the postresection defect during lateral skull base surgery.

The vast majority of benign tumors of the cerebellopontine angle, temporal bone, and parotid gland can be successfully resected without permanent injury to the facial nerve. Malignant tumors or recurrent disease may require facial nerve sacrifice, especially if preoperative facial paresis is present. This article will present case examples of the various methods to reconstruct facial animation after lateral skull base resections that require sacrifice of cranial nerve VII, and the associated mimetic facial musculature. Facial mimetic outcome after reanimation was graded using the House-Brackmann scale. Primary neurorrhaphy or interposition grafting may be performed when both the proximal and distal portions of the facial nerve are available and viable facial musculature is present. If only the distal facial nerve and viable facial musculature are available, a split hypoglossal to facial nerve anastomosis is used. A proximal facial nerve to microvascular free flap is performed when the proximal facial nerve is available without distal nerve or viable musculature. A cross-facial to microvascular free flap is performed when the proximal and distal facial nerve and facial musculature are unavailable. The above methods resulted in a House-Brackmann score of III/VI in all case examples postoperatively. The method of facial reanimation used depends on the availability of viable proximal facial nerve, the location of healthy, tumor-free distal facial nerve, and the presence of functioning facial mimetic musculature.

Neoplastic causes of nonacute facial paralysis: A review of 221 cases.

We conducted a retrospective review to assess the clinical presentation of patients with tumor-related nonacute complete peripheral facial weakness or an incomplete partial facial paresis and to provide an algorithm for the evaluation and management of these patients. Our study population was made up of 221 patients-131 females and 90 males, aged 14 to 79 years (mean: 49.7)-who had been referred to the Facial Nerve Disorders Clinic at our tertiary care academic medical center over a 23-year period with a documented neoplastic cause of facial paralysis. In addition to demographic data, we compiled information on clinical signs and symptoms, radiologic and pathologic findings, and surgical approaches. All patients exhibited gradual-onset facial weakness or facial twitching. Imaging identified an extratemporal tumor in 128 patients (58%), an intratemporal lesion in 55 patients (25%), and an intradural mass in 38 (17%). Almost all of the extratemporal tumors (99%) were malignant, while 91% of the intratemporal and intradural tumors were benign. A transtemporal surgical approach was used in the 93 intratemporal and intradural tumor resections, while the 128 extratemporal lesions required a parotidectomy with partial temporal bone dissection. The vast majority of patients (97%) underwent facial reanimation. We conclude that gradual-onset facial paralysis or twitching may occur as a result of a neoplastic invasion of the facial nerve along its course from the cerebellopontine angle to the parotid gland. We caution readers to beware of a diagnosis of "atypical Bell's palsy."

Grading Facial Nerve Function Following Combined Static and Mimetic Surgical Techniques.

Objective To present a grading scale to assess the functional recovery of the facial nerve in patients who have undergone mimetic and static surgical techniques for facial reanimation. Study design This is a proposed new facial nerve grading system that will be demonstrated with specific case presentations. All patients underwent a variety of neural grafting, microvascular free-flap reconstruction, or surgical static procedures. Results The proposed facial nerve grading scale is one that has not been described previously in the literature and is applicable to a unique patient population. Its ease of use in this patient population will allow otolaryngologists to assess facial recovery accurately and quickly in cases where the facial nerve is not anatomically intact. Conclusion The proposed facial recovery grading scale provides an efficient means of grading facial recovery for a unique group of patients who previously could not be followed. The proposed scale is practical and easy to use in a clinical setting.

The Envoy Esteem implantable hearing system.

This article discusses the Envoy Esteem implantable hearing system, a completely implantable hearing device. The device is indicated for patients older than 18 years with stable moderate to severe sensorineural hearing loss and good speech discrimination. The device is placed through an intact canal wall tympanomastoidectomy with a wide facial recess approach. The implant is typically activated at 6 to 8 weeks postoperatively and usually requires several adjustments for optimal performance. The sound processor/battery lasts 4.5 to 9.0 years and can be replaced through a minor outpatient procedure.

Intracranial facial nerve crush injury and facial motor nuclei cell loss in rats.

OBJECTIVES: The purpose of this study was to (1) assess the degree of motoneuron cell loss and (2) the combinatorial effects of electrical stimulation (ES) and testosterone propionate (TP) on cell survival following an intracranial facial nerve crush injury and (3) compare these results to distal injuries. STUDY DESIGN: Prospective, randomized, controlled animal study. METHODS: Sprague-Dawley rats were randomly divided into 3 groups: intracranial sham surgery or intracranial crush injury with or without ES and TP treatments. The intracranial sham group underwent exposure of the meatal segment of the right facial nerve. The intracranial crush groups underwent a crush of the meatal segment following exposure with or without ES and TP treatment immediately following the injury and followed for 8 weeks. Brain sections were thionin-stained, and facial motor nuclei (FMN) were counted using light microscopy. Results were compared to intratemporal and extracranial facial nerve crush injuries. RESULTS: Intracranial crush injury resulted in a significant decrease in cell survival (n = 6) of 65.6% as compared to the sham group (99.4%; n = 9). The treatments increased cell survival to 93.8% (n = 2). The cell loss in the intracranial facial nerve injury is more substantial than the intratemporal (85.8%; n = 7) and extracranial (103.3%; n = 4) injuries. CONCLUSIONS: Intracranial injury results in a more profound cell loss compared to the distal injuries. These data suggest a critical importance for the development of treatment modalities that can help improve cell survival following facial nerve injuries.

Cochlear implant extrusion secondary to keloid formation.

OBJECTIVE AND IMPORTANCE: The goal of this paper is to describe a previously unreported etiology for cochlear implant extrusion. A short literature review is included. This paper represents the first reported case of cochlear implant extrusion secondary to keloid formation. CLINICAL PRESENTATION: We present the case of a 40-year-old male who underwent cochlear implant insertion approximately 5 years prior who later developed a 5 cm post-auricular soft tissue swelling and partial extrusion which interfered with implant function. INTERVENTION: He subsequently underwent wound debridement, cochlear implant removal, and rotational skin flap closure. Final pathology revealed keloid scar. CONCLUSION: Cochlear implant extrusion is a rare complication which has been attributed to various causes. This report identifies keloid formation as another possible source.

Recurrent post-tympanostomy tube otorrhea secondary to aerobic endospore-forming bacilli: a case report and brief literature review.

We report a unique case in which a 57-year-old man with an 8-year history of late recurrent post-tympanostomy tube otorrhea (PTTO) was found to harbor Bacillus subtilis, an aerobic endospore-forming bacillus that is typically resistant to chemical and physical agents because of its unique life cycle. Removal of the patient's tympanostomy tube resulted in complete resolution of his long-standing otorrhea. We also review the etiologies of and treatment strategies for early, late, chronic, and recurrent PTTO. We conclude that regardless of the etiology, a patient with persistent or recurrent PTTO should consider undergoing removal of the ventilation tube.

Body mass index predicts risk for complications from transtemporal cerebellopontine angle surgery.

OBJECTIVES: To determine the relationship between body mass index (BMI) and risk for specific complications from transtemporal cerebellopontine angle (CPA) surgery for nonmalignant disease. STUDY DESIGN: Case series with chart review. SETTING: Tertiary-care academic hospital. SUBJECTS AND METHODS: Retrospective review of 134 consecutive patients undergoing transtemporal cerebellopontine angle surgery for nonmalignant disease from 2009 to 2011. Data were collected regarding demographics, body mass index, intraoperative details, hospital stay, and complications including cerebrospinal fluid leak, wound complications, and brachial plexopathy. RESULTS: One hundred thirty-four patients were analyzed with a mean preoperative body mass index of 28.58. Statistical analysis demonstrated a significant difference in body mass index between patients with a postoperative cerebrospinal fluid leak and those without (P = .04), as well as a similar significant difference between those experiencing postoperative brachial plexopathy and those with no such complication (P = .03). Logistical regression analysis confirmed that body mass index is significant in predicting both postoperative cerebrospinal fluid leak (P = .004; odds ratio, 1.10) and brachial plexopathy (P = .04; odds ratio, 1.07). Elevated body mass index was not significant in predicting wound complications or increased hospital stay beyond postoperative day 3. CONCLUSION: Risk of cerebrospinal fluid leak and brachial plexopathy is increased in patients with elevated body mass index undergoing surgery of the cerebellopontine angle. Consideration should be given to preoperative optimization via dietary and lifestyle modifications as well as intraoperative somatosensory evoked potential monitoring of the brachial plexus to decrease these risks.

Single session of brief electrical stimulation immediately following crush injury enhances functional recovery of rat facial nerve.

Peripheral nerve injuries lead to a variety of pathological conditions, including paresis or paralysis when the injury involves motor axons. We have been studying ways to enhance the regeneration of peripheral nerves using daily electrical stimulation (ES) following a facial nerve crush injury. In our previous studies, ES was not initiated until 24 h after injury. The current experiment tested whether ES administered immediately following the crush injury would further decrease the time for complete recovery from facial paralysis. Rats received a unilateral facial nerve crush injury and an electrode was positioned on the nerve proximal to the crush site. Animals received daily 30 min sessions of ES for 1 d (day of injury only), 2 d, 4 d, 7 d, or daily until complete functional recovery. Untreated animals received no ES. Animals were observed daily for the return of facial function. Our findings demonstrated that one session of ES was as effective as daily stimulation at enhancing the recovery of most functional parameters. Therefore, the use of a single 30 min session of ES as a possible treatment strategy should be studied in human patients with paralysis as a result of acute nerve injuries.

Preauricular infratemporal fossa approach for advanced malignant parotid tumors.

OBJECTIVES/HYPOTHESIS: The aims of this study were to demonstrate the surgical technique involved in the preauricular infratemporal fossa (ITF) approach, outline the clinical indications for use of this technique, and present the results in using this approach in 159 patients with malignant parotid tumors. At the conclusion of this article, the reader should be able to understand the utility of the preauricular infratemporal fossa approach in the management of patients with advanced malignant parotid tumors. STUDY DESIGN: This was a retrospective chart review of 159 patients treated at a tertiary care academic medical center following institutional review board approval. METHODS: A comprehensive medical records review was performed for all patients with malignant parotid tumors who underwent a preauricular ITF approach between July 1988 and July 2010. RESULTS: The most common presenting symptoms were pain and trismus, whereas the presence of a parotid mass and facial paralysis were the most common clinical signs. Mucoepidermoid and adenoid cystic carcinoma accounted for 63% of the tumors, and perineural invasion was found in nearly 71% of the patients. Despite negative surgical margins in 92% of the patients, local or regional tumor recurrence was found in 17% of the cases. The mean follow-up time was 12.8 years. CONCLUSIONS: The preauricular ITF approach should be used in the surgical extirpation of advanced malignant parotid neoplasms. This technique provides proximal facial nerve identification, internal carotid artery protection, and negative tumor margins at the skull base.

A rat model for intracranial facial nerve crush injuries.

OBJECTIVE: (1) Explain the need for an animal model to study intracranial injuries to the facial nerve. (2) Describe various techniques attempted to identify and crush the intracranial segment of the facial nerve in a rat model. (3) Describe in detail a successful rat model of intracranial facial nerve crush injury. STUDY DESIGN: Randomized controlled animal study. SETTING: Animal laboratory. SUBJECTS AND METHODS: Multiple attempts at surgical approaches to the cerebellopontine angle were attempted on cadaveric rats. Once a successful approach was derived, this was used on 19 live rats under anesthesia. Fourteen rats had a 1-minute facial nerve crush performed, and 5 had a sham surgery with complete surgical exposure of the facial nerve but no crush. Rats were followed for a 12-week duration evaluating immediate postoperative facial nerve function, complications, and survival. RESULTS: All 14 (100%) rats that underwent surgery with crush injury had complete facial paralysis postoperatively. Complete facial paralysis was defined as loss of eye-blink reflex, flat vibrissae, and lack of vibrissae movement. The 5 sham surgery rats had complete facial function postoperatively. Surgery was performed by 2 separate surgeons with no difference in outcome between the 2. Complications occurred in only 1 animal (1/19, 5.3%), which was a corneal abrasion requiring sacrifice. CONCLUSION: Our group describes a consistent method for performing an intracranial crush injury in the rat. This new model and its applications in translational facial nerve research are promising, particularly with tumors or lesions at the cerebellopontine angle.

Lateral temporal bone and parotid malignancy with facial nerve involvement.

OBJECTIVES: To review our institution's experience and outcomes in the treatment of lateral temporal bone (LTB) and parotid malignancy with facial nerve (FN) involvement. To identify risk factors for treatment failures and to clarify previously established prognostic factors for this advanced-stage disease. STUDY DESIGN: Case series with chart review. SETTING: Tertiary care academic hospital. SUBJECTS AND METHODS: A series of 26 patients treated operatively for malignancy of the LTB and parotid gland with FN involvement were reviewed retrospectively. All patients underwent sacrifice of the FN due to intraoperative determination of nerve invasion. Demographic, historical, intraoperative, pathologic, and follow-up data were collected and analyzed to determine survival outcomes and locoregional control. Risk factor analysis was performed. RESULTS: The FN was found to be grossly involved by tumor at the stylomastoid foramen in 57.7% of patients, resulting in sacrifice more proximally in the vertical segment in 57.7%. Statistical analysis demonstrated a locoregional recurrence rate of 34.6%, with the majority of recurrence occurring within the first 2 years after surgery. The rate of distant failure was 15.4%. Kaplan-Meier and chi-square analysis showed an overall survival of 76.0%, 66.7%, 35.3%, 31.2%, and 28.6% at 1, 2, 3, 4, and 5 years, respectively. Advanced age, the presence of tumor of epithelial origin, and pathologically positive lymph nodes are significantly predictive of poor survival. CONCLUSION: Outcomes of malignancy of the LTB with FN involvement treated with primary surgical therapy compare favorably with previously published control rates, and overall prognosis for this condition is likely better than historically established.

Contemporary options for lateral skull base reconstruction following tumor extirpation.

PURPOSE OF REVIEW: This review is timely and relevant for several reasons. More lateral skull base tumors are being diagnosed, as the threshold to image patients with lower cranial nerve symptoms is very low. Patients are living longer and can potentially have more comorbidities that can affect wound healing. More surgical teams are attempting lateral skull base surgery. Patients with benign and malignant tumors of the lateral skull base may also be treated with radiotherapy and chemotherapy, which can have implications for wound healing. RECENT FINDINGS: Abdominal fat grafting continues to be a viable option for closure of defects resulting from transtemporal skull base surgery. Hydroxyapatite cranioplasty remains controversial due to a high incidence of delayed infection. For malignant lateral skull base lesions such as advanced temporal bone and parotid malignancies, free tissue transfer is increasingly utilized, as it is reliable, is harvested outside the surgical field, and provides superior wound closure. Bone anchored hearing aids (BAHAs) can be a good option for hearing rehabilitation, whereas vistafix can reliably address auricular deformities. SUMMARY: Proper reconstruction after tumor resection in skull base surgery is important to prevent postoperative complications. This article will address contemporary reconstruction options including primary closure, abdominal fat grafting, synthetic materials, microvascular free tissue transfer, BAHA and vistafix.

Osseointegrated implant applications in cosmetic and functional skull base rehabilitation.

This study discusses the indications, outcomes, and complications in patients that underwent osseointegrated implantation for skull base rehabilitation. We conducted a retrospective review of eight patients with skull base defects who had undergone implantation of a facial prosthetic retention device ± bone-anchored hearing aid at a tertiary academic referral center. Descriptive analysis of applications, techniques, outcomes, and complications were reviewed. The majority of patients were males (n = 6) with previously diagnosed skull base malignancy (n = 5) with an average age of 46 (range, 14 to 77). All patients received an implanted facial prosthetic device either for an aural (n = 7) or orbital (n = 1) prosthesis. There were only two complications that included infection (n = 1) and implant extrusion (n = 1). Osseointegrated implantation of abutments for anchoring prosthetic devices in patients for skull base rehabilitation provides an excellent cosmetic option with minimal complications.

Temporal bone osteoradionecrosis after surgery and radiotherapy for malignant parotid tumors.

OBJECTIVE: To assess the incidence of osteoradionecrosis (ORN) of the temporal bone after surgery with radiotherapy for malignant parotid tumors. SETTING: A tertiary care, academic medical center. PATIENTS: All patients who underwent surgical resection with postoperative radiotherapy (RT) for a malignant parotid tumor between July 1988 and July 2007. INTERVENTIONS: A retrospective chart analysis to determine the extent of surgery, the RT parameters, and the incidence of ORN of the temporal bone. MAIN OUTCOME MEASURES: The incidence of ORN in 3 subgroups of patients. RESULTS: The 221 patients with malignant parotid tumors who underwent surgical resection with postoperative RT were divided into groups 1, parotidectomy only; 2, parotidectomy with mastoidectomy; and 3, parotidectomy with subtotal petrosectomy. The overall incidence of temporal bone ORN in group 1 was 2 (2%) of 106; in group 2, 8 (13%) of 64; and in group 3, 0 (0%) of 51. CONCLUSION: The incidence of temporal bone ORN is higher after mastoidectomy for facial nerve identification or resection in patients undergoing parotidectomy with postoperative radiotherapy. Oversew of the ear canal with mastoid obliteration should be considered in this subgroup of patients to avoid this long-term complication of radiotherapy used in the treatment of malignant parotid tumors.