Radiological evaluation of the facial nerve.

The methodology for evaluation of the facial nerve (CT and MR technique) is presented and the need for routine use of gadolinium-DTPA with MRI is emphasized. The various disorders causing facial palsy with their clinical and radiological features are described. Although tumors only cause 6% of facial nerve disorders, they require a thorough radiologic workup. Schwannoma is the most common neoplasm arising from the facial nerve and can occur anywhere along the nerve course: cerebellopontine angle and internal auditory canal, geniculate ganglion, or tympanic, mastoid and intraparotid segments.