Bell's Palsy - Facial Nerve palsy

Bell’s palsy is a benign inflammatory disease of
unknown etiology, which results from compression or
inflammation of the facial nerve. It may occur following exposure to cold or a viral infection (herpes simplex
and varicella zoster) and is generally associated with
edema, entrapment, and ischemia of the facial nerve
within the narrow bony canal. This condition, which
accounts for about 80% of all cases of facial palsy,
may accompany otitis media, mastoiditis, and petrositis and may occur in diabetic patients and pregnant
woman. Despite the benign nature of the disease, signifcant anxiety is endured by patients due to the fear
of stroke or permanent facial disfgurement. Patients
exhibit abrupt or progressive unilateral weakness of
the facial muscles (facial asymmetry, depression of the
angle of mouth), which may be preceded or accompanied by earache. Glandular secretion, stapedius muscle
function, and taste sensation often remain unaffected.
Epiphora (excessive tearing) due to ectropion and lagophthalmos (inability to close the eye completely) due
to weakness of the orbicularis oculi muscle also occur.
The latter can also be seen in comatose patients and
individuals with blepharoplasty. The oculoauricular
reflex, which is characterized by posterior movement
of the ear when the patient directs his/her gaze as far
laterally as possible, is lost in Bell’s palsy. Patients
may exhibit Bell’s phenomenon, in which the eye turns
upward and outward without accompanying eyelid
closure. Recurrence is seen in approximately 10% of
Bell’s palsy patients. Unilateral recurrent facial palsy,