Bell's Palsy

One fine morning a 15-year-old boy noticed that he is unable to close the left eye. The nasolabial fold was flattened on the left side and the mouth was deviated to the right side.

1. What is the most probable diagnosis?
2. What special precaution should be taken to protect the left eye?
3. What is the prognosis of recovery usually in such patients?

Answers:


1. What is the most probable diagnosis?

Answers: This boy is exhibiting the features of facial nerve palsy on the left side. It is most probably Bell’s palsy. It is characterized by acute unilateral facial nerve palsy that is not associated with other cranial nerve palsy or brainstem dysfunction. It may occur at any age. It usually develops abruptly 2 weeks after a systemic viral infection. The viruses that have been implicated with this disease are EBV and lyme disease, herpes simplex and mumps virus. Instead of an active viral invasion, an allergic or immune-demyelinating facial neuritis following infection is thought to be responsible for its causation.

2. What special precaution should be taken to protect the left eye? 

Answer: The patient is unable to close the eye on the affected side, so is vulnerable to suffer from exposure keratitis. Therefore, it is of vital importance to protect this eye by repeated instillation of methylcellulose eye drops/ointment. Additionally, it should be closed at the time of sleeping with the help of a micropore tape for better results.

3. What is the prognosis of recovery usually in such patients?

Answer: Prognosis of recovery in Bell palsy is excellent as more than 85% of patients recover spontaneously with no residual facial weakness while 10% have mild facial weakness. Only 5% are left with severe facial weakness. With poor recovery other causes of facial nerve palsy should be considered.