Cranial Nerve Neoplasms ; pathology ; Geniculate Ganglion ; pathology ; Humans ; Meningeal Neoplasms ; pathology ; Meningioma ; pathology

The present study was undertaken to analyze the radiologic findings of intratemporal and extratemporal schwannoma (ITS & ETS). We retrospectively reviewed the CT (9 cases), MR (3 cases) and medical records of 10 facial schwannoma patients. After classifying these into ITS and ETS, radiologic and clinical findings were analyzed. The most common clinical manifestations were facial nerve dysfunction (6/6 cases, 100%) and hearing impairment (5/6 cases, 83.3%) in ITS and parotid mass (4/4 cases, 100%) in ETS. Geniculate ganglion (GG) was the most commonly involved segment of ITS (5/6 cases, 83.5%). On CT, ITS arising in GG (4 cases) showed erosion of the petrous bone (4 cases), cochlea (3 cases), lateral semicircular canal (1 case) and ossicles (3 cases). ITS arising in the mastoid segment (1 case) showed the destruction of the jugular plate and external auditory canal wall. All three ITS in which MRI was performed showed iso- to hypointensity on T1WI, hyperintensity on T2WI and well-enhanced on post-enhanced T1WI. ETS showed various findings, but all four ETS were located in the posterolateral portion of the retromandibular vein and extended toward the stylomastoid foramen. In conclusion, ITS shows the schwannoma on MR. ETS shows various findings. However, if the tumor is located along the extratemporal facial nerve course, then facial schwannoma may be suspected.
Adult ; Cranial Nerve Neoplasms/diagnosis* ; Facial Nerve* ; Female ; Geniculate Ganglion/radiography ; Geniculate Ganglion/pathology ; Human ; Magnetic Resonance Imaging* ; Male ; Middle Age ; Neurilemmoma/diagnosis* ; Tomography, X-Ray Computed*

BACKGROUND AND OBJECTIVES: Magnetic resonance imaging(MRI) with gadolimiun, an intravenous paramagnetic agent, shows non-enhancement of the cranial nerves in normal subjects. In the presence of inflammation or edema, gadolinium is absorbed into these tissues, resulting in enhancement on T1-weighted images. The purpose of this study was to evaluate the clinical implication of gadolinium-enhanced MRI in Bell's palsy. MATERIALS AND METHODS: From 1994 to 1998, 19 patients with Bell's palsy were evaluated to assess the efficacy of gadolinium-enhanced MRI in determining the frequency, the site of facial nerve enhancement, and the relationship between electroneuronography(ENoG) findings and gadolinium-enhanced MRI. The data was compared to 40 patients with sudden sensorineural hearing loss who had temporal bone MRI. RESULTS: On gadolinium-enhanced MRI, 16 of 19 patients had abnormal contrast enhancement of the facial nerve, but nobody had abnormal contrast enhancement of the facial nerve in the control group. In particular, facial nerve enhancement was identified in the distal portion of the internal auditory canal, geniculate ganglion, labyrinthine segment (n=10), tympanic segment (n=10), and mastoid segment (n=7) of the facial nerve. The facial nerve was enhanced more frequently in patients in whom the degeneration of ENoG was more than 50%. The facial nerve was more frequently enhanced in patients who had a higher House-Blackmann grade. CONCLUSION: Gadolinium-enhanced MRI plays a important role in diagnosing Bell's palsy and in predicting the location of pathology of the facial nerve.
Bell Palsy* ; Cranial Nerves ; Edema ; Facial Nerve ; Gadolinium ; Geniculate Ganglion ; Hearing Loss, Sensorineural ; Humans ; Inflammation ; Magnetic Resonance Imaging* ; Mastoid ; Pathology ; Temporal Bone