Bell’s Palsy

Overview

Bell’s Palsy is an acute lower motor neuron facial paralysis, usually unilateral. It is the most common cause of LMN facial paralysis.

Etiology

The exact cause is unknown, but several theories exist:

1. Viral Infection (Most Accepted)
   • Viral prodrome in ~60% of patients.
2. Vascular Ischemic Neuropathy
   • Exposure to cold leads to vasospasm of vasa nervosa supplying the facial nerve.
   • Causes metabolite accumulation, nerve edema, and compression within its bony canal, exacerbating ischemia.
3. Autoimmune Reactions

Clinical Picture

1. Paralysis: Acute LMNL unilateral facial paralysis, either partial or complete.
2. Viral Prodrome: Present in ~60% of cases.
3. Ear Pain: Present in 50% of patients, may precede paralysis.
4. Impairment of Taste: Occurs in 50% of patients.
5. Phonophobia: Intolerance of loud sounds due to stapedius paralysis.
6. Prognosis: Generally good, with about 85% achieving complete recovery and ~3% showing no recovery.

Treatment

1. General Management of Facial Nerve Paralysis:

   • Eye Care:
     • Closure of the eye.
     • Eye refreshment drops.
     • Eye ointment.

2. Medical Treatment: ( must  be started  in   the   first   3   days)        in the form of:

   • Corticosteroids: Prednisolone in dose of 1mg/kg body weight/day tapered   in   10-15   days   (  to decrease  edema of the nerve).
   • Acyclovir Tablets: tablets  for one week  (Viral theory).

3. Surgical Treatment:

   • Nerve Decompression: of the nerve through middle cranial fossa approach is advised by some surgeons. If there is more than 90% degeneration within 3 weeks as shown by ENOG.Z

   

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