INTENSITY OF MR CONTRAST ENHANCEMENT DOES NOT CORRESPOND TO CLINICAL AND ELECTRONEUROGRAPHIC FINDINGS IN ACUTE INFLAMMATORY FACIAL-NERVE PALSY

PURPOSE: To determine the value of MR contrast enhancement in predicti ng the course of acute inflammatory facial nerve palsy and in selectin g patients for surgical decompression. METHODS: Six patients with an a cute inflammatory incomplete or complete peripheral facial nerve palsy (five idiopathic and one herpetic in origin) had repeated MR imaging studies with and without contrast enhancement, electroneurography, and clinical examinations to establish a connection between the intensity of contrast enhancement on MR images, the clinical condition, and the electrophysiological data. The examinations were performed every seco nd day starting on the first day of admission until clinical recovery was proved by clinical deblockage (spontaneous clinical improvement), The last examination was performed 3 months after the onset of the fac ial nerve palsy. RESULTS: An abnormal, very intense contrast enhanceme nt of the facial nerve was always present in the distal intrameatal an d proximal tympanic segments and in the geniculate ganglion. The labyr inthine segment exhibited a mild to moderate enhancement, and the dist al tympanic and mastoid segments showed a moderate to intense enhancem ent. The intensity of contrast enhancement did not correspond to the s everity, duration, or course of the facial nerve palsy, and the electr oneurographic data had no predictive value in indicating the severity of the inflammatory process. Three months after clinical recovery, a p ersistent and more or less unchanged or even slightly more intense con trast enhancement was observed, CONCLUSION: The long-lasting intense c ontrast enhancement seen in the facial nerve segments of patients who have acute peripheral inflammatory facial nerve palsy is explained by a two-phase breakdown of the blood-nerve barrier.