Bell palsy has been most strongly associated with reactivation of which organism?

Correct answer: C. Herpes simplex virus type 1

• A. Candida has no role in facial nerve palsy.
• B. CMV causes opportunistic disease in immunocompromised patients and is not the organism associated with Bell palsy.
• C. CORRECT. Reactivation of latent HSV-1 within the geniculate ganglion is the leading aetiological hypothesis for Bell palsy. Viral inflammation causes oedema and compression of the facial nerve within the narrow bony facial canal, producing acute lower motor neuron facial paralysis.
• D. EBV is associated with infectious mononucleosis and oral hairy leukoplakia rather than facial paralysis.

Note: Do not confuse this with RAMSAY HUNT SYNDROME, which is facial palsy from VARICELLA-ZOSTER reactivation in the geniculate ganglion, accompanied by vesicles in the ear canal or on the palate and often with hearing loss and vertigo. Ramsay Hunt has a worse prognosis and needs antivirals plus steroids. The key dental distinction from a central lesion: Bell palsy involves the FOREHEAD (the patient cannot wrinkle the brow or close the eye); a stroke spares the forehead because of bilateral cortical innervation.