Bell Palsy

Question 1

Involved CN?

Answer 1

CN VII

Question 2

Cause?

Answer 2

Uncertain… possible viral etiology (herpes simplex)

URI = common preceding event

Question 3

Clinical features

Answer 3

Acute onset unilateral facial weakness/paralysis…. both upper and lower parts of face are affected

• Inability to raise eyebrow or close eye
• Drooping of mouth corner
• Disappearance of nasolabial fold
• Decreased tearing
• Hyperacusis
• Loss of taste sensation over anterior 2/3 of tongue

Question 4

Dx

Answer 4

Clinical, but consider Lyme disease in endemic areas as tx is different

Do NOT use steroids if Lyme is suspected!!!

(the use of cortico-steroids will replicate the spirochetal bacteria that cause Lyme disease)

Question 5

Tx

Answer 5

• Usually none is required, as most cases resolve in 1 mo.
• Short course of steroid therapy (prednisone) and acyclovir, if necessary
• Pt should wear eye patch at night to prevent corneal abrasion
• Surgical decompression of CN VII if paralysis progresses

Question 6

Differential Diagnosis for Facial Nerve Palsy

Answer 6

• Trauma (e.g., temporal bone, forceps delivery)
• Lyme disease
• Tumor (acoustic neuroma, cholesteatoma, neurofibroma)
• GBS (palsy is usually bilateral)
• Herpes zoster

Question 7

Location of lesion

Answer 7

Below facial nucleus (below the pons)

Lesions in CNS occurring above facial nucleus –> contralateral lower facial weakness that spares the forehead