Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 24-31: Bell Palsy + Key Features Download Section PDF Listen +++ +++ Essentials of Diagnosis ++ Sudden onset of lower motor neuron facial palsy May have hyperacusis or impaired taste No other neurologic abnormalities +++ General Considerations ++ Idiopathic lower motor neuron facial paresis Attributed to an inflammatory reaction of the facial nerve near the stylomastoid foramen or in the bony facial canal Reactivation of herpes simplex or varicella zoster virus has been postulated Common in pregnancy or in diabetes mellitus + Clinical Findings Download Section PDF Listen +++ +++ Symptoms and Signs ++ Generally comes on abruptly, but may worsen over 1 or 2 days Pain about the ear often precedes or accompanies the weakness but usually lasts for only a few days There may be ipsilateral restriction of eye closure and difficulty with eating and fine facial movements A disturbance of taste is common, owing to involvement of chorda tympani fibers, and hyperacusis due to involvement of fibers to the stapedius occurs occasionally Vesicles may be observed in the external ear canal in cases due to herpes zoster infection +++ Differential Diagnosis ++ HIV-related facial neuropathies Lyme disease Sarcoidosis Ramsay Hunt syndrome (herpes zoster of geniculate ganglion) Acoustic neuroma Acute or chronic otitis media Malignant otitis externa Guillain-Barré syndrome Tumor, eg, parotid, temporal bone tumor Brainstem infarct + Diagnosis Download Section PDF Listen +++ ++ Clinical features are characteristic Electromyography and nerve excitability or conduction studies provide a guide to prognosis +++ Laboratory Tests ++ to exclude other causes of facial neuropathy (see Differential Diagnosis) + Treatment Download Section PDF Listen +++ +++ Medications ++ Corticosteroids increase the chance of a complete recovery at 9–12 months by 12–15% Prednisone 60 mg orally daily for 5 days followed by a 5-day taper or Prednisolone 25 mg orally twice daily for 10 days It is helpful to protect the eye with lubricating drops (or lubricating ointment at night) and a patch if eye closure is not possible Acyclovir or valacyclovir is only indicated when there is evidence of herpetic vesicles in the external ear canal +++ Surgery ++ There is no evidence that surgical procedures to decompress the facial nerve are of benefit +++ Therapeutic Procedures ++ The management is controversial Approximately 60% recover completely without treatment Physical therapy may improve facial function + Outcome Download Section PDF Listen +++ +++ Prognosis ++ Patients with clinically complete palsy when first seen are less likely to make a full recovery than those with an incomplete one A poor prognosis for recovery is also associated with advanced age, hyperacusis, and severe initial pain + Reference Download Section PDF Listen +++ + +Gagyor I et al. Antiviral treatment of Bell's palsy (idiopathic facial paralysis). Cochrane Databse Syst Rev. 2019 Sep 5;9:CD001869. [PubMed: 31486071]