Role of magnetic resonance imaging in the diagnosis of bilateral facial paralysis.

Bilateral facial paralysis (BFP) is a rare clinical finding that may be caused by Guillain-Barré syndrome, a medical emergency. The differential diagnosis of BFP is lengthy but can be narrowed to a limited group of disorders by the patient's history and physical examination. The most important diagnostic tests to obtain initially are the lumbar puncture and magnetic resonance imaging (MRI) scan with gadolinium contrast enhancement. Based on the MRI and lumbar puncture findings, additional tests may be appropriately ordered. The diagnosis of bilateral Bell's palsy is made by exclusion of other disorders. This report presents five cases of BFP (Guillain-Barré syndrome, herpes simplex polyneuritis, meningeal lymphoma, and two cases of bilateral Bell's palsy) in which MRI imaging helped in the diagnosis and subsequent management of the patient. The appropriate sequence of diagnostic studies for patients with BFP is discussed.