Temporal lobe injury with middle fossa approach to intracanalicular vestibular schwannomas: a systematic review.

There are several surgical approaches for vestibular schwannoma (VS) resection. However, management has gradually shifted from microsurgical resection, toward surveillance and radiosurgery. One of the arguments against microsurgery via the middle fossa approach (MFA) is the risk of temporal lobe retraction injury or sequelae. Here, we sought to evaluate the incidence of temporal lobe retraction injury or sequela from a MFA via a systematic review of the existing literature. This systematic review was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Relevant studies reporting temporal lobe injury or sequela during MFA for VS were identified. Data was aggregated and subsequently analyzed to evaluate the incidence of temporal lobe injury. 22 studies were included for statistical analysis, encompassing 1522 patients that underwent VS resection via MFA. The overall rate of temporal lobe sequelae from this approach was 0.7%. The rate of CSF leak was 5.9%. The rate of wound infection was 0.6%. Meningitis occurred in 1.6% of patients. With the MFA, 92% of patients had good facial outcomes, and 54.9% had hearing preservation. Our series and literature review support that temporal lobe retraction injury or sequelae is an infrequent complication from an MFA for intracanalicular VS resection.

The relationship of inter-implant time and hearing outcomes for bilateral cochlear implants.

PURPOSE: Determine the relationship between time elapsed between sequential bilateral cochlear implantation (BiCI) and speech intelligibility scores in post-lingually deafened adults. MATERIALS AND METHODS: Retrospective review of post-lingually deafened adults who received bilateral cochlear implants from January 1, 2011 to January 1, 2018 at an ambulatory tertiary referral center. RESULTS: 113 patients (226 cochlear implants) were initially reviewed, with 56 patients (112 implants) being included in the final analysis. Median inter-implant interval was 187.5 days (IQ range 54.25-346.5). Maximum interval was 1787 days. Mean age at first implant was 60.66 ± 13.37. Bilateral AzBio score in quiet and inter-implant interval showed no significant correlation (r = 0.034, p = 0.815). There was no significant difference in mean bilateral AzBio scores in quiet between the simultaneous and sequential implantation groups (p = 0.22). Similar non-significant results were seen when examining the correlation between AzBio Difference and inter-implant interval (r = -0.07, p = 0.66). No significant result between mean AzBio Difference of simultaneous and sequential implant recipients was found (p = 0.06). CONCLUSIONS: For the inter-implant intervals examined, there seems to be no significant decline in speech intelligibility scores for patients receiving sequential bilateral cochlear implants compared to simultaneously implanted patients. There was no significant correlation noted between increasing inter-implant intervals and speech intelligibility scores.

En bloc resection of the temporal bone and temporomandibular joint for advanced temporal bone carcinoma.

Advanced skin malignancies involving the temporal bone can involve the temporomandibular joint and glenoid fossa. Many of these tumors can be removed with a lateral temporal bone resection; however, extensive involvement of the glenoid fossa should include an en bloc resection of the temporal bone, glenoid fossa, and condyle. We describe a novel surgical approach that is an extension of a temporal bone resection that includes the glenoid fossa and condyle in an en bloc resection with the temporal bone. This procedure has been performed in 7 patients with advanced carcinoma of the temporal bone involving the glenoid fossa. There were no short-term complications as a result of the surgical approach. The addition of a middle fossa craniotomy and inclusion of the glenoid fossa and condyle as part of an en bloc resection of the temporal bone can be performed safely.

Cochlear implantation requiring a retrofacial approach to the round window.

OBJECTIVE: To describe three cases of cochlear implantation utilizing a retrofacial approach to the round window. STUDY DESIGN: Retrospective case review. PATIENTS: Three patients with sensorineural hearing loss undergoing cochlear implantation. INTERVENTIONS: Cochlear implantation via a retrofacial approach to the round window. RESULTS: Three patients were noted to have inadequate visualization of the round window using a standard posterior tympanotomy at the time of their cochlear implant surgery. A retrofacial approach was performed to provide exposure of the round window to ensure correct placement of the electrode array. Intraoperative photos and postoperative imaging are demonstrated. CONCLUSION: When a laterally or anteriorly positioned facial nerve obscures visualization of the round window, a retrofacial approach is a possible route to visualize the round window.

Recurrent meningitis secondary to a petrous apex meningocele.

This case report describes a patient who was found to have a cerebrospinal fluid (CSF) leak originating from the petrous apex. The patient initially presented with multiple bouts of meningitis. The patient was treated surgically via a middle cranial fossa approach but presented five years later with recurrent meningitis and was found to have an osseous defect of the petrous apex which was not recognized prior to the initial surgery.

Intratemporal traumatic neuromas of the facial nerve: evidence for multiple etiologies.

OBJECTIVE: To describe 2 patients with traumatic neuromas of the intratemporal facial nerve in the absence of trauma. STUDY DESIGN: Retrospective case review. SETTING: Tertiary care referral center. PATIENTS: Patients included underwent resection of an intratemporal facial nerve mass. Upon pathologic evaluation, the patients were found to have traumatic neuromas of the facial nerve. INTERVENTION(S): Patients underwent resection of an intratemporal facial traumatic neuroma. Histopathologic evaluation was performed including an immunohistochemistry evaluation. RESULTS: Two patients were identified with intratemporal facial nerve traumatic neuromas. The patients had no significant history of trauma or chronic inflammatory process. Pathologic evaluations, including immunohistochemistry, of the excised masses were consistent with traumatic neuromas. All tumors were noted to have a disorganized collection of axons and were not consistent with the expected diagnosis of schwannoma. Tumors involved the tympanic and vertical segments of the facial nerve. A cavernous angioma was found within one mass and is thought to be the etiology of neuroma formation. CONCLUSION: Traumatic neuromas are possible in the intratemporal facial nerve in the absence of trauma. A cavernous angioma of the facial nerve is a newly described possible cause of traumatic neuroma formation.

Elevated intracranial pressure in patients with spontaneous cerebrospinal fluid otorrhea.

OBJECTIVES/HYPOTHESIS: To determine the prevalence of elevated intracranial hypertension in patients with spontaneous cerebrospinal fluid otorrhea (SCSFO). STUDY DESIGN: Case series with chart review at a tertiary care academic medical center following institutional review board approval. METHODS: A retrospective review was performed of patients undergoing operative repair of SCSFO between January 2007 and May 2012. RESULTS: Thirty-eight patients underwent operative repair of SCSFO. Of these, 22 underwent postoperative lumbar puncture with measurement of opening pressure. The opening pressure was elevated (> 20 cm/H2 0) in eight patients (36.4%). Preoperative magnetic resonance imaging was available for review by a neuroradiologist in 27 patients. Radiographic evidence of elevated intracranial pressure (ICP) was present in 48.1% of patients. CONCLUSION: Elevated ICP is common in patients with SCSFO. However, as only a minority of patients have elevated ICP, it is not the sole factor in the development of SCSFO.

Superior semicircular canal dehiscence in patients with spontaneous cerebrospinal fluid otorrhea.

OBJECTIVE: To determine the prevalence of superior semicircular canal dehiscence (SCD) in patients with spontaneous cerebrospinal fluid (CSF) otorrhea. STUDY DESIGN: Case series with chart review. SETTING: Tertiary care referral center. SUBJECTS AND METHODS: Patients included have undergone a middle fossa craniotomy for repair of spontaneous CSF otorrhea between January 2007 and December 2011. The main outcome measure is the presence or absence of SCD observed during spontaneous CSF leak repair. Computed tomography (CT) imaging was also reviewed to determine the diagnostic accuracy of this modality. RESULTS: Thirty-three ears in 31 patients underwent surgical repair for spontaneous CSF otorrhea via a middle fossa craniotomy. The average age at the time of repair was 60.5 years, and 80.6% of patients were female. A dehiscence of the superior canal was observed in 15.2% of ears (16.1% of individuals). No significant difference in age, body mass index, or sex was noted between those patients with or without a superior canal dehiscence. For the diagnosis of SCD, coronal CT was 100% sensitive and 91.7% specific. The positive predictive value and negative predictive value of CT were 66.7% and 100%, respectively. CONCLUSION: The prevalence of superior semicircular canal dehiscence in ears with spontaneous otorrhea is 15.2%. This prevalence is greater than the 0.5% reported in a temporal bone study of ears not selected for CSF otorrhea.

The association of meningitis with postoperative cerebrospinal fluid fistula.

Objective To determine the risk factors for and the clinical course of postoperative meningitis following lateral skull base surgery and to determine its relationship to cerebrospinal fluid (CSF) fistula. Patients Patients undergoing lateral skull base surgery between July 1999 and February 2010 at an academic tertiary referral center. All subjects had culture-proven meningitis or suspected bacterial meningitis in the postoperative period. Medical records were compared with the lateral skull base patients who did not develop meningitis. Results Of 508 procedures, 16 patients developed meningitis (3.1%). The most common diagnosis was acoustic neuroma in 81.3%; 68.8% of patients had a CSF leak prior to onset of meningitis, and 50% received a lumbar drain. The median time from surgery to the onset of meningitis was 12 days with a range of 2 to 880 days. The relative risk of developing meningitis in the setting of postoperative CSF fistula is 10.2 (p < 0.0001). No meningitis-associated mortality was observed. Conclusions Postoperative meningitis occurred in a small number of patients undergoing lateral skull base surgery. A postoperative CSF fistula leads to an increased risk of meningitis by a factor of 10.2.

Lumbar subarachnoid drainage in cerebrospinal fluid leaks after lateral skull base surgery.

OBJECTIVE: To determine the efficacy of lumbar drainage in managing cerebrospinal fluid (CSF) leak after lateral skull base surgery. STUDY DESIGN: Retrospective case review. SETTING: Academic tertiary referral center. PATIENTS: Patients who had a lumbar subarachnoid drain placed after a lateral skull base procedure between July 1999 and February 2010 were included. INTERVENTIONS: Patients were identified by searching medical records for lateral skull base approach Current Procedural Terminology codes. The following variables were recorded for each subject: diagnosis, type of lateral skull base operation, duration of lumbar drainage, need for revision surgery, and presence of meningitis. MAIN OUTCOME MEASURE: Successful cessation of postoperative CSF leakage. RESULTS: Five hundred eight charts were reviewed, and 63 patients were identified who received a lumbar drain after a lateral skull base operation. The most common diagnosis was acoustic neuroma in 61.9%. The most common skull base approaches were the translabyrinthine, middle fossa, and transpetrosal approaches. Approximately 60.3% of patients had CSF rhinorrhea, 23.8% had an incisional leak, and 14.3% had otorrhea. The mean duration of lumbar drainage was 4.6 days. Forty eight (76.2%) study subjects had resolution of their CSF leak with lumbar drainage. Fifteen patients (23.8%) required revision surgery to stop the CSF leak. Lumbar drainage was successful in 90% of leaks after the translabyrinthine approach but in only 50% of those undergoing a suboccipital approach, which was a statistically significant difference. CONCLUSION: Postoperative CSF leaks after lateral skull base surgery can be managed with a lumbar subarachnoid drain in a majority of cases but is more successful after the translabyrinthine than the suboccipital approach. Recurrent CSF leaks after lumbar drainage is likely to require a revision operation.