Question

A 58-year-old man develops sudden weakness of one side of his face and is diagnosed with acute idiopathic lower motor neurone facial nerve palsy. There is no vesicular rash, no ear discharge, and no evidence of stroke.

Which management option has the strongest evidence base?

a. Immediate facial nerve decompression surgery
b. Oral valaciclovir alone
c. Reassurance only, with no active treatment
d. Oral valaciclovir plus prednisolone for all patients
e. Oral prednisolone

Answer

e. Oral prednisolone

Detailed explanation

Bell’s palsy is an acute, unilateral, idiopathic lower motor neurone facial nerve palsy.

The key evidence-based treatment is:

Oral prednisolone, ideally started within 72 hours of symptom onset.

Prednisolone improves the chance of complete facial nerve recovery. The presumed mechanism is reduction of inflammation and oedema around the facial nerve, especially within the narrow facial canal, where swelling may compress the nerve.

Bell’s palsy is a lower motor neurone facial nerve palsy, so the whole side of the face is affected, including the forehead. This is an important distinction from an upper motor neurone facial palsy, such as stroke, where the forehead is relatively spared because of bilateral cortical innervation of the upper facial muscles.

Typical Bell’s palsy features include:

• Sudden unilateral facial weakness
• Inability to close the eye
• Flattening of the nasolabial fold
• Drooping of the mouth
• Forehead weakness
• Post-auricular pain
• Altered taste
• Hyperacusis
• Dry eye or watering eye

The most important associated management issue is eye protection. If the patient cannot close the eye properly, they are at risk of exposure keratopathy. They should receive artificial tears during the day, lubricating ointment at night, and eyelid taping at night if eye closure is incomplete.

Why the other options are wrong

a. Immediate facial nerve decompression surgery

This is not routine management of Bell’s palsy. Surgical decompression has been considered historically, but it is not recommended as standard treatment because evidence of benefit is poor and the risks are significant. Bell’s palsy is usually treated medically, not surgically.

b. Oral valaciclovir alone

Antiviral therapy alone is not recommended. Although herpes simplex virus has been proposed as a possible trigger in some cases, trials have not shown antivirals alone to be as effective as corticosteroids. The key proven treatment is prednisolone.

c. Reassurance only, with no active treatment

Many patients recover spontaneously, but no treatment is not the best answer because prednisolone significantly improves the likelihood of full recovery when started early. Untreated patients have a higher risk of persistent facial weakness.

d. Oral valaciclovir plus prednisolone for all patients

Combination treatment may be considered in selected severe cases, especially if there is severe facial paralysis or suspicion of viral involvement, but it is not the standard evidence-based answer for all patients. The strongest routine recommendation is prednisolone alone within 72 hours. If there are vesicles, severe otalgia, or features suggesting Ramsay Hunt syndrome, antiviral therapy becomes much more important.

Key exam point

Bell’s palsy should be treated with oral prednisolone within 72 hours of symptom onset.

Very important treatment point / clinical trap

Do not forget eye care. In Bell’s palsy, inability to close the eye can cause exposure keratopathy and corneal ulceration. Prescribe artificial tears, nighttime lubricating ointment, and tape the eye closed at night if needed.

Cheat sheet for exam

• Bell’s palsy = acute idiopathic unilateral lower motor neurone facial nerve palsy.
• Lower motor neurone facial palsy affects the forehead.
• Upper motor neurone facial palsy usually spares the forehead.
• First-line treatment: oral prednisolone within 72 hours.
• Antivirals alone are not recommended.
• Antivirals plus steroids may be considered in severe palsy, but steroids are the key evidence-based treatment.
• Ramsay Hunt syndrome = facial palsy + ear vesicles ± severe otalgia → treat with steroids plus antivirals.
• Eye protection is essential if the patient cannot close the eye.
• Use artificial tears during the day.
• Use lubricating eye ointment at night.
• Tape the eye closed at bedtime if closure is incomplete.
• If no improvement after 3 weeks, refer urgently to ENT.
• Most patients recover fully within 3–4 months.
• Untreated Bell’s palsy may lead to persistent moderate to severe weakness in a minority of patients.
• Long-term complications include synkinesis, facial contracture, crocodile tears, and persistent weakness.

Flash cards

Q: What is Bell’s palsy?
A: Acute, unilateral, idiopathic lower motor neurone facial nerve palsy.
Explanation: It is a diagnosis of exclusion after ruling out stroke, Ramsay Hunt syndrome, otitis media, parotid disease, Lyme disease, and other secondary causes.

Q: What is the first-line treatment for Bell’s palsy?
A: Oral prednisolone.
Explanation: It should ideally be started within 72 hours of symptom onset to improve the chance of complete recovery.

Q: Why does Bell’s palsy affect the forehead?
A: Because it is a lower motor neurone facial nerve palsy.
Explanation: A lesion of the facial nerve after the facial nucleus affects all muscles of facial expression on that side.

Q: Why is the forehead spared in many strokes causing facial weakness?
A: Because the upper face has bilateral cortical innervation.
Explanation: Therefore, an upper motor neurone lesion usually causes lower facial weakness with relative forehead sparing.

Q: Are antivirals alone recommended in Bell’s palsy?
A: No.
Explanation: Antivirals alone do not provide the same proven recovery benefit as corticosteroids.

Q: When may antivirals be added to steroids?
A: In severe facial palsy or if viral aetiology is strongly suspected.
Explanation: They are especially important if Ramsay Hunt syndrome is suspected.

Q: What eye complication must be prevented in Bell’s palsy?
A: Exposure keratopathy.
Explanation: Incomplete eye closure dries the cornea and can lead to ulceration.

Q: What eye care should be given in Bell’s palsy?
A: Artificial tears, lubricating ointment at night, and eyelid taping if needed.
Explanation: These measures protect the cornea until facial nerve function returns.

Q: When should Bell’s palsy be referred urgently to ENT?
A: If there is no improvement after 3 weeks.
Explanation: Persistent palsy may indicate an alternative diagnosis or need specialist assessment.

Q: What is the usual prognosis of Bell’s palsy?
A: Most patients recover fully within 3–4 months.
Explanation: Early steroid treatment improves the likelihood of complete recovery.

MCQs

MCQ 1

A 47-year-old woman presents with sudden left facial weakness. She cannot wrinkle the left side of her forehead and cannot close the left eye. There is no limb weakness, no vesicular rash, and no dysphasia. Symptoms began 24 hours ago.

What is the best treatment?

a. Aspirin
b. Oral prednisolone
c. Oral aciclovir alone
d. Immediate CT head and thrombolysis
e. No treatment

Answer: b. Oral prednisolone

Explanation: This is classic Bell’s palsy: acute unilateral lower motor neurone facial nerve palsy involving the forehead. The best evidence-based treatment is oral prednisolone within 72 hours. Antivirals alone are not recommended. Stroke is less likely because the forehead is affected and there are no cortical or limb signs.

MCQ 2

Which feature best supports a lower motor neurone facial nerve palsy rather than an upper motor neurone facial palsy?

a. Forehead involvement
b. Preserved eye closure
c. Isolated drooping of the mouth with forehead sparing
d. Contralateral hemiparesis
e. Expressive dysphasia

Answer: a. Forehead involvement

Explanation: A lower motor neurone facial nerve palsy affects the entire ipsilateral face, including the forehead. Upper motor neurone lesions usually spare the forehead because the upper facial muscles receive bilateral cortical innervation.

MCQ 3

Which of the following is false regarding Bell’s palsy?

a. It is usually unilateral
b. It is a lower motor neurone facial nerve palsy
c. Prednisolone is most effective when started within 72 hours
d. Antiviral monotherapy is the standard first-line treatment
e. Eye protection is important if eye closure is incomplete

Answer: d. Antiviral monotherapy is the standard first-line treatment

Explanation: Antiviral monotherapy is not recommended. The standard evidence-based treatment is oral prednisolone within 72 hours. Antivirals may be added in selected severe cases or if viral aetiology is suspected, but they are not the main proven treatment.

MCQ 4

A 62-year-old man has right-sided facial weakness and painful vesicles in the external auditory canal. He also complains of vertigo and reduced hearing.

What is the most likely diagnosis?

a. Bell’s palsy
b. Ramsay Hunt syndrome
c. Myasthenia gravis
d. Trigeminal neuralgia
e. Parotid malignancy

Answer: b. Ramsay Hunt syndrome

Explanation: Facial palsy with painful ear vesicles suggests Ramsay Hunt syndrome due to varicella-zoster virus reactivation in the geniculate ganglion. It is not simple idiopathic Bell’s palsy. Treatment usually includes corticosteroids plus antiviral therapy.

MCQ 5

In Bell’s palsy, what is the most important non-pharmacological management issue?

a. Speech therapy for all patients on day 1
b. Routine surgical decompression
c. Eye protection
d. Immediate anticoagulation
e. Avoidance of all facial movement

Answer: c. Eye protection

Explanation: Eye protection is essential if the patient cannot close the eye. Exposure keratopathy can cause corneal damage. Artificial tears, lubricating ointment, and eyelid taping may be needed.

MCQ 6

A patient with Bell’s palsy is unable to close the affected eye at night. What is the most appropriate advice?

a. Leave the eye uncovered to avoid infection
b. Use artificial tears only if pain develops
c. Tape the eye closed at bedtime and use eye lubrication
d. Start long-term antibiotics
e. Arrange urgent facial nerve decompression

Answer: c. Tape the eye closed at bedtime and use eye lubrication

Explanation: Incomplete eye closure risks corneal drying and exposure keratopathy. The eye should be protected using artificial tears, lubricating ointment, and taping closed at night if required.

MCQ 7

Which statement about the timing of steroid therapy in Bell’s palsy is most accurate?

a. Steroids are only useful after 2 weeks
b. Steroids should ideally be started within 72 hours
c. Steroids are contraindicated in all patients over 60
d. Steroids are useful only if vesicles are present
e. Steroids should be delayed until MRI confirms facial nerve inflammation

Answer: b. Steroids should ideally be started within 72 hours

Explanation: The key exam point is that oral prednisolone should be started within 72 hours of symptom onset. Early treatment gives the best chance of complete recovery.

MCQ 8

Which of the following is false regarding upper motor neurone facial weakness?

a. It may occur in stroke
b. It often causes contralateral lower facial weakness
c. The forehead is usually relatively spared
d. It causes complete ipsilateral facial paralysis including the forehead
e. It may be associated with limb weakness or dysphasia

Answer: d. It causes complete ipsilateral facial paralysis including the forehead

Explanation: Complete ipsilateral facial paralysis including the forehead suggests a lower motor neurone lesion. Upper motor neurone facial weakness usually affects the contralateral lower face with relative forehead sparing.

MCQ 9

A 55-year-old man diagnosed with Bell’s palsy has no improvement after 3 weeks.

What is the most appropriate next step?

a. Urgent ENT referral
b. Reassure and review after 1 year
c. Stop all treatment and discharge
d. Start aspirin lifelong
e. Arrange carotid endarterectomy

Answer: a. Urgent ENT referral

Explanation: If Bell’s palsy shows no sign of improvement after 3 weeks, urgent ENT referral is recommended. Persistent weakness raises concern for alternative diagnoses or complicated recovery.

MCQ 10

Which of the following symptoms may occur in Bell’s palsy due to facial nerve involvement?

a. Hyperacusis
b. Complete sensory loss over the entire face
c. Homonymous hemianopia
d. Expressive aphasia
e. Spastic paraparesis

Answer: a. Hyperacusis

Explanation: Hyperacusis may occur because the facial nerve supplies stapedius. Other associated symptoms include altered taste, post-auricular pain, dry eye, and facial weakness.

MCQ 11

A patient has acute facial palsy. Which finding would be most concerning for an alternative diagnosis rather than simple Bell’s palsy?

a. Post-auricular discomfort
b. Altered taste
c. Hyperacusis
d. Gradual progressive facial weakness over several months
e. Inability to close the eye

Answer: d. Gradual progressive facial weakness over several months

Explanation: Bell’s palsy is acute. Slowly progressive facial weakness suggests another cause, such as parotid malignancy, cerebellopontine angle lesion, chronic infection, or other structural pathology.

MCQ 12

Which of the following is the best description of Bell’s palsy?

a. Acute idiopathic unilateral lower motor neurone facial nerve palsy
b. Chronic bilateral upper motor neurone facial weakness
c. Facial weakness caused by middle cerebral artery infarction
d. Facial sensory loss caused by trigeminal nerve disease
e. Painful ophthalmoplegia due to cavernous sinus thrombosis

Answer: a. Acute idiopathic unilateral lower motor neurone facial nerve palsy

Explanation: Bell’s palsy is an acute, unilateral, idiopathic facial nerve palsy of lower motor neurone type. The forehead is affected.

MCQ 13

Which of the following is false regarding prognosis in Bell’s palsy?

a. Most patients recover fully
b. Recovery commonly occurs within 3–4 months
c. Early prednisolone improves the chance of full recovery
d. All untreated patients develop permanent severe paralysis
e. Some patients may develop persistent weakness or synkinesis

Answer: d. All untreated patients develop permanent severe paralysis

Explanation: Most patients recover, even without treatment, but untreated patients have a higher risk of persistent moderate to severe weakness. It is not true that all untreated patients develop permanent severe paralysis.

MCQ 14

A 40-year-old pregnant woman develops acute unilateral lower motor neurone facial weakness. Which statement is most accurate?

a. Bell’s palsy is less common in pregnancy
b. Bell’s palsy is more common in pregnancy
c. Pregnancy rules out Bell’s palsy
d. Surgical decompression is mandatory
e. Antiviral monotherapy is first-line

Answer: b. Bell’s palsy is more common in pregnancy

Explanation: Bell’s palsy is more common in pregnant women. The same key principles apply: confirm the diagnosis, consider differential diagnoses, give early corticosteroids where appropriate, and protect the eye.

MCQ 15

A patient with Bell’s palsy asks why the eye feels dry. What is the best explanation?

a. The optic nerve is inflamed
b. The cornea has become anaesthetic due to trigeminal nerve destruction
c. Incomplete eyelid closure causes exposure of the ocular surface
d. The lacrimal gland always becomes permanently non-functional
e. Dry eye excludes Bell’s palsy

Answer: c. Incomplete eyelid closure causes exposure of the ocular surface

Explanation: Facial nerve palsy impairs eyelid closure. This exposes the cornea and conjunctiva, causing dryness, irritation, and risk of exposure keratopathy.

Summary for quick exam revision

Bell’s palsy is an acute, unilateral, idiopathic lower motor neurone facial nerve palsy. The whole ipsilateral face is affected, including the forehead, which helps distinguish it from an upper motor neurone lesion such as stroke. The most evidence-based treatment is oral prednisolone, ideally started within 72 hours of symptom onset. Antiviral therapy alone is not recommended. Steroids plus antivirals may be considered in severe facial palsy or when viral involvement is strongly suspected, but the key exam answer for routine Bell’s palsy is prednisolone. Ramsay Hunt syndrome should be suspected if facial palsy is associated with painful ear vesicles, severe otalgia, hearing symptoms, or vertigo. Typical Bell’s palsy symptoms include post-auricular pain, altered taste, dry eye, hyperacusis, facial droop, and inability to close the eye. Eye care is a major management priority because incomplete eye closure can cause exposure keratopathy and corneal ulceration. Artificial tears, lubricating ointment, and taping the eye closed at night may be required. Surgical decompression is not routine management. If there is no improvement after 3 weeks, urgent ENT referral is recommended. Most patients recover fully within 3–4 months, especially with early corticosteroid treatment. Persistent weakness, synkinesis, and facial contracture can occur in a minority of patients. The key exam phrase is: Bell’s palsy equals prednisolone within 72 hours plus eye protection.