Bifid Facial Nerve with Dual Origin Identified During Resection of Vestibular Schwannoma.

Facial nerve identification and preservation is a critical step in the resection of vestibular schwannoma. The use of intraoperative neurostimulation to positively identify the facial nerve along its entire course is essential to prevent injury. To our knowledge, this is the first reported case of a bifid facial nerve with a dual origin at the brainstem, which we observed during resection of vestibular schwannoma via the translabyrinthine approach. Both roots were visualized to join as one facial nerve trunk outside the brainstem in the cisternal segment of the facial nerve, and both trunks demonstrated positive signal with neurostimulation. This case highlights an important anatomic variation and also the importance of correct identification of facial nerve anatomy during resection of vestibular schwannoma and other pathologies within the cerebellopontine angle.

A morphometric study of the structures bordering the infra-cochlear corridor - Relevant for endoscopic/microscopic ear surgery.

Application of surgical endoscope, used alone or in combination with the surgical microscope, for the operative management of ear and temporal bone conditions may allow improved access and clearance of disease. Preservation of normal structures may also be improved. As the use of this tool is increasing, the need for better understanding of the anatomy of the ear is becoming evident. This is particularly so for endoscopic surgery aiming at removal of lesions involving the infra-cochlear corridor and/or petrous apex. Human temporal bone-derived labyrinth casts (molds), originally made for endolymphatic duct and sac analysis which genuinely represent the membranous labyrinth and its adjacent soft tissues, were morphometrically analyzed in terms of the anatomic relations between structures in and around the infra-cochlear corridor. The distance between the petrous carotid artery (PCA) and the basal turn of the cochlea, the distance between PCA and infra-cochlear vein (ICV)/cochlear aqueduct (CA), and the distance between the lower surface of basal cochlear turn and the point where the carotid artery and jugular vein (JV) meet close to the jugular foramen, were measured to be around 1.3 mm, 6 mm and 8 mm respectively, thus constituting an approximate 6 × 8 mm2 infra-cochlear corridor. This analysis and further study with larger samples might be helpful for operation via this corridor led to the petrous apex where cholesterol granuloma, cholesteatoma and other lesions are not uncommon.

Diagnosis and Management of Dural Sinus Thrombosis following Resection of Cerebellopontine Angle Tumors.

Objective Lateral sinus thrombosis is a potentially devastating but seldom studied complication of cerebellopontine angle (CPA) tumor surgery. Systemic anticoagulation in the early postoperative period has often been avoided due to the potential risks of intracranial hemorrhage. Design Retrospective review. Setting Tertiary referral center. Main Outcome Measures The goal of this study was to identify the frequency, treatment, and outcomes in patients who develop postoperative venous sinus thrombosis following CPA tumor surgery and receive early systemic anticoagulation. Results Of 43 patients with CPA tumors, we report five patients (11.6%) with transverse and/or sigmoid sinus thrombosis following resection of the tumor, four of which were detected on routine early postoperative noncontrast computed tomography (CT) scan. The thrombosis was confirmed in all cases with CT venography or magnetic resonance venography. Affected patients had significantly larger tumors than controls and tended to undergo longer operations. These patients were treated with immediate anticoagulation (intravenous heparin, followed by Coumadin for 6 months) without complication. Conclusion Venous sinus thrombosis is an underrecognized complication of CPA surgery, but it can be diagnosed in the early postoperative period by noncontrast CT imaging. Early postoperative initiation of systemic anticoagulation appears safe and effective to prevent the progression of thrombosis and its consequences.

Extensive craniocervical pneumocranium.

The authors report the first case of extensive craniocervical pneumocranium causing mass effect, without any associated extradural pneumatocele. The patient presented with frontal headaches and unusual sensations in his left ear. He was found to have large pneumocranium involving his left frontal, temporal, parietal, and occipital bones as well as the atlas. He underwent a craniectomy with replacement of the pneumatized bone with titanium mesh, and mastoidectomy with obliteration of the mastoid air cells. This case is discussed in the context of the literature to date. A review of the literature shows that trauma is not a common cause of pneumocranium, with most cases occurring spontaneously. The authors believe that a combined neurosurgical-otological approach is beneficial in such cases.

Quality of life among acoustic neuroma patients managed by microsurgery, radiation, or observation.

OBJECTIVE: The main aim of this study was to examine differences in quality of life (QoL) among acoustic neuroma patients across the management options of microsurgery, radiation, and observation. Additional aims were to describe QoL and investigate management, medical, and demographic factors that predicted QoL in this patient group. STUDY DESIGN: Cross-sectional design, using a postal questionnaire. SETTING: Tertiary referral centers. PATIENTS: Participants included 180 adults diagnosed with, or treated for, a unilateral acoustic neuroma within 5 years of questionnaire distribution. The mean age of participants was 56.5 years, and 107 (59.4%) were female. INTERVENTION(S): Patients' acoustic neuromas were managed with microsurgery, radiation, or observation. MAIN OUTCOME MEASURE(S): Current QoL was measured using the Short Form 12 Version 2 (SF-12), and postmanagement changes in QoL were assessed with the Glasgow Benefit Inventory (GBI). RESULTS: No significant differences in SF-12 scores were found across microsurgery, radiation, and observation patients. However, microsurgery patients reported more deterioration on the GBI general well-being subscale than radiation patients and more improvement in the GBI social support scale than observation patients. Number of symptoms was a consistent predictor of SF-12 and GBI scores. CONCLUSION: This is only the second study to use multivariate statistical techniques and a large sample to examine QoL across the acoustic neuroma management options of microsurgery, radiation, and observation. There were few differences in QoL outcomes across management groups. Number of symptoms was an important factor in current QoL and postmanagement changes in QoL.

Otogenic cranial base osteomyelitis: a proposed prognosis-based system for disease classification.

OBJECTIVES: To review the presentation, microbiology, and long-term results of treating otogenic cranial base osteomyelitis to develop a prognosis-based disease classification system. PATIENTS AND METHODS: Thirty-eight patients with otogenic cranial base osteomyelitis treated between 1989 and 2002 were studied. Patient demographics, presentation, pathogens, details of therapy, and disease-specific survival were recorded. Patients were stratified using Technetium-99 single-photon emission computerized tomography (SPECT) at presentation into 4 grades: I, mild uptake; II, focal mastoid/temporal bone uptake not reaching midline; III, petrous temporal bone uptake reaching midline; and IV, uptake crossing midline, involving the contralateral temporal bone. Actuarial analysis was used to identify prognostic factors. RESULTS: There were 27 men. The average age at presentation was 65 +/- 16 years (range, 19-95 yr). The median age-adjusted Charlson comorbidity score was 5, and 63% of patients were diabetic. The most common presenting symptoms were pain and otorrhea, and 8 patients had cranial nerve neuropathy. Pseudomonas aeruginosa was the most common bacterial pathogen (n = 28; 74%), and 9 patients had fungal or mixed infections. On average, antibiotics were administered for 161 days, and 6 patients had concomitant surgery. The average follow-up was 33 months, and 3-year disease-specific survival was 76%. Univariate predictors of survival were the SPECT grade, fungal/mixed infections, Charlson score, immune compromise, and cranial nerve neuropathy. The only independent predictor of survival on multivariate Cox regression was the SPECT stage at presentation. CONCLUSION: Cranial base osteomyelitis is associated with significant morbidity and mortality and requires prolonged treatment. Long-term outcome can be predicted from the initial SPECT scan.

Asymmetrical hearing loss.

BACKGROUND: General practitioners are usually the first point of contact for patients with hearing loss. Asymmetrical sensorineural hearing loss can be a symptom of a wide range of diseases. A correct diagnosis is essential for appropriate treatment and limitation of the progression of hearing loss. OBJECTIVE: This article provides an outline for an approach to a patient presenting with asymmetrical sensorineural hearing loss, and also provides a brief summary of four disease processes which may present with asymmetrical hearing loss. DISCUSSION: Asymmetrical sensorineural hearing loss may be secondary to the process of aging or simply be related to excessive noise exposure. It can however, be the only presenting symptom of a vestibular schwannoma or an intracranial tumour. A high level of clinical suspicion is required to ensure that these pathologies are not missed.