Jeffrey T. Vrabec

Coronal Computed Tomography Prevalence of Superior Semicircular Canal Dehiscence

OBJECTIVES The relatively new clinical entity superior canal dehiscence syndrome (SCDS) is diagnosed by clinical symptoms and signs. Coronal computed tomography (CT) has been used to confirm the diagnosis. A consecutive series of temporal bone CT scans was reviewed to define the prevalence of a dehiscent-appearing superior semicircular canal. STUDY DESIGN AND SETTING Temporal bone CT scans performed over a 2-year period at a university-based tertiary referral center were reviewed independently by 3 individuals. Scans were excluded if coronal images were not obtained or reconstructed from axial images. Prevalence figures for dehiscent-appearing superior semicircular canal were determined by consensus. Medical records of selected individuals with a dehiscent-appearing canal were reviewed for study indications and otologic symptoms. RESULTS A dehiscent-appearing superior semicircular canal was seen in 9% of studies. Correlation among examiners was greater than 94%. Medical records indicated symptoms suggestive of or compatible with the diagnosis of SCDS in rare cases. CONCLUSION The prevalence of a dehiscent-appearing superior semicircular canal on coronal CT of the temporal bones performed with 1.0-mm collimation is substantially greater than that predicted by temporal bone histologic study. Clinical symptoms compatible with the diagnosis were seldom recorded, suggesting low specificity. The high sensitivity and low specificity of CT scan create a risk for overdiagnosis of SCDS if the coronal CT scans are not correlated with clinical symptoms.

Facial Nerve Grading System 2.0

Objective: To present an updated version of the original Facial Nerve Grading Scale (FNGS), commonly referred to as the House-Brackmann scale. Study Design: Controlled trial of grading systems using a series of 21 videos of individuals with varying degrees of facial paralysis. Results: The intraobserver and interobserver agreement was high among the original and revised scales. Nominal improvement is seen in percentage of exact agreement of grade and reduction of instances of examiners differing by more then one grade when using FNGS 2.0. FNGS 2.0 also offers improved agreement in differentiating between grades 3 and 4. Conclusion: FNGS 2.0 incorporates regional scoring of facial movement, providing additional information while maintaining agreement comparable to the original scale. Ambiguities regarding use of the grading scale are addressed.

Otomycosis: Clinical features and treatment implications

OBJECTIVES: To determine the clinical presentation, predisposing factors, complications, and treatment outcomes of otomycosis. STUDY DESIGN AND SETTING: Retrospective review of 132 patients with a clinical diagnosis of otomycosis treated from 1998 to 2004 in an academic otology practice. RESULTS: Otalgia and otorrhea were the most common presenting complaints (48%). Prior otologic procedures increase the risk of developing otomycosis. Residual disease was observed in 13% and recurrence in 15% of the subjects. The presence of a mastoid cavity was associated with higher recurrent and residual disease rates. Topical ketoconazole, cresylate otic drops, and aluminum acetate otic drops were all relatively effective with >80% resolution rate on initial application, although topical ketoconazole had a higher resolution rate and lower rate of disease recurrence. CONCLUSIONS AND SIGNIFICANCE: Otomycosis can usually be diagnosed by clinical examination and often occurs in the setting of persistent otorrhea. Complications are not uncommon but usually resolve with application of appropriate topical antifungal agents. Eradication of disease is more difficult in the presence of a mastoid cavity.

Central projections of the saccular and utricular nerves in macaques

The central projections of the utricular and saccular nerve in macaques were examined using transganglionic labeling of vestibular afferent neurons. In these experiments, biotinylated dextran amine was injected directly into the saccular or utricular neuroepithelium of fascicularis (Macaca fascicularis) or rhesus (Macaca mulatta) monkeys. Two to 5 weeks later, the animals were killed and the peripheral vestibular sensory organs, brainstem, and cerebellum were collected for analysis. The principal brainstem areas of saccular nerve termination were lateral, particularly the spinal vestibular nucleus, the lateral portion of the superior vestibular nucleus, ventral nucleus y, the external cuneate nucleus, and cell group l. The principal cerebellar projection was to the uvula with a less dense projection to the nodulus. Principle brainstem areas of termination of the utricular nerve were the lateral/dorsal medial vestibular nucleus, ventral and lateral portions of the superior vestibular nucleus, and rostral portion of the spinal vestibular nucleus. In the cerebellum, a strong projection was observed to the nodulus and weak projections were present in the flocculus, ventral paraflocculus, bilateral fastigial nuclei, and uvula. Although there is extensive overlap of saccular and utricular projections, saccular inputs to the lateral portions of the vestibular nuclear complex suggest that saccular afferents contribute to the vestibulospinal system. In contrast, the utricular nerve projects more rostrally into areas of known concentration of vestibulo‐ocular related cells. Although sparse, the projections of the utricle to the flocculus/ventral paraflocculus suggest a potential convergence with floccular projection inputs from the vestibular brainstem that have been implicated in vestibulo‐ocular motor learning. J. Comp. Neurol. 466:31–47, 2003.

Adult Spontaneous CSF Otorrhea: Correlation with Radiographic Empty Sella:

OBJECTIVE: To determine the prevalence of radiographic empty sella in patients with spontaneous cerebrospinal fluid (CSF) otorrhea. STUDY DESIGN AND SETTING: Retrospective case series of adult patients with CSF otorhinorrhea at an academic tertiary medical center. Patients with history of skull base surgery, trauma, tumor, or chronic ear disease were excluded. Available imaging studies were reviewed with attention to the sella turcica. RESULTS: Eight patients were diagnosed with spontaneous CSF otorrhea. Five of seven patients with adequate imaging studies (71%) had a radiographic empty sella. Seven of eight patients were clinically obese, with a body mass index BMI >30 kg/m 2 . CONCLUSIONS: Empty sella is a common radiologic finding in patients with spontaneous CSF otorrhea. This supports the theory that increased intracranial pressure contributes to development of spontaneous CSF otorrhea. SIGNIFICANCE: Radiographic empty sella predicts elevated intracranial pressure, which may require further evaluation and treatment in patients with spontaneous CSF otorrhea. EBM rating: C-4

Herpes Simplex Virus and Meniere's Disease

Objective/Hypothesis This study was designed to investigate the hypothesis that Menieres disease is associated with herpes simplex virus (HSV) reactivation in the vestibular ganglion.

Bell's palsy and pregnancy

Objective To describe the epidemiology, pathophysiology, presentation, treatment, and prognosis of Bells palsy (BP) in pregnancy. RESULTS The incidence of BP in pregnant women is not significantly greater than expected compared to all women of childbearing age. There is a high incidence of cases in the third trimester and corresponding low incidence during early pregnancy. CONCLUSION There is no conclusive evidence that the etiology of BP in pregnancy is different than in nonpregnant patients. Altered susceptibility to herpes simplex viral reactivation during pregnancy is the most likely explanation for concentration of cases in the third trimester. Outcome may be poorer in pregnant patients, though historically, treatment is often withheld from these patients. SIGNIFICANCE Management of BP in pregnancy can mirror that of nonpregnant individuals with the exception of first-trimester cases.

Inverting Papilloma of the Temporal Bone

Objectives Inverting papilloma of the temporal bone is exceedingly rare. The objective is to familiarize the clinician with the clinical presentation and prognosis of this entity.

Genetic Investigations of Meniere's Disease

Menieres disease remains a disorder of unknown origin despite the collective efforts to determine the pathogenesis, although experts have long recognized that disease development likely has some heritable component. Although genetic studies of Menieres disease have been inconclusive, increasing knowledge of human genetic structure and mutation and investigative techniques have potential to further understanding of this disorder.

Advanced pediatric mastoiditis with and without intracranial complications

Recently, several groups have noticed an increase in cases of advanced pediatric mastoiditis and intracranial complications. The objective of this study was to review the bacteriology of advanced mastoiditis in pediatric patients, with the hypothesis that a difference in bacteriology might explain the development of an intracranial complication.