Cranial Nerve Palsy - VII : Facial Nerve

Question 1

Motor Functions of the Facial Nerve.

Answer 1

1. Muscles of Facial Expression.

2. Lacrimal, Submandibular, Sublingual Glands and Mucous Glands of Nose and Mouth.

Question 2

Sensory Functions of the Facial Nerve.

Answer 2

1. External Ear.
2. Taste from Anterior 2/3 Tongue.
3. Hard and Soft Palate.

Question 3

Cranial Fossa and Facial Nerve.

Answer 3

Internal Acoustic Meatus.

Question 4

Clinical Features of Intracranial Facial Nerve Palsy (3).

Answer 4

1. Chorda Tympani - Reduced Salivation and Loss of Taste.
2. Nerve to Stapedius - Sound Hypersensitivity.
3. Greater Petrosal Nerve - Reduced Lacrimal Fluid Production.

Question 5

Clinical Features of Extracranial Facial Nerve Palsy.

Answer 5

MOTOR - Paralysis or Severe Weakness of Muscles of Facial Expression.

Question 6

Aetiology of Intracranial Facial Nerve Palsy.

Answer 6

1. Infection related to external or middle ear.

2. Idiopathic - BELL’S PALSY.

Question 7

Aetiology of Extracranial Facial Nerve Palsy (4).

Answer 7

1. Parotid Gland Pathology.
2. Infection - Herpes.
3. Compression - Forceps Delivery.
4. Idiopathic - BELL’S PALSY.

Question 8

Clinical Features of Bell’s palsy (4).

Answer 8

1. Acute Onset of Unilateral LMN Weakness (not Extraocular).
2. Mild-Moderate Postauriculaar Otalgia.
3. Hyperacusis.
4. Nervus Intermedius (Altered Taste and Dry Eyes).

Question 9

Management of Bell’s palsy.

Answer 9

1. Prompt administration of oral steroids - Prednisolone 50mg for 10 days followed by a taper.
2. Supportive- Artificial Tears and Ocular Lubricants.
3. Refer urgently to ENT if no improvement after 3 weeks.
4. Should recover within 3-4 months.

Question 10

Features Suggestive of Ramsay-Hunt Syndrome (2).

Answer 10

1. Prominent Otalgia.

2. Vesicular Rash in External Auditory Meatus, Palate or Tongue.

Question 11

Epidemiology of Bell’s palsy.

Answer 11

1. 20-40.

2. Commoner in pregnancy.

Question 12

Pathophysiology of Ramsay-Hunt Syndrome.

Answer 12

Reactivation of VZV in Geniculate Ganglion in CN VII.

Question 13

Management of Ramsay-Hunt Syndrome.

Answer 13

Oral Aciclovir and Corticosteroids.

Question 14

Aetiology of Bilateral Facial Nerve Palsy (5).

Answer 14

1. Sarcoidosis.
2. GBS.
3. Lyme disease.
4. Bilateral Acoustic Neuromas (Neurofibromatosis Type II).
5. Bell’s palsy.

Question 15

Aetiology of Unilateral Facial Nerve Palsy - LMN (7).

Answer 15

1. Bell’s palsy.
2. Ramsay-Hunt Syndrome (Herpes Zoster).
3. Acoustic Neuroma.
4. Parotid Tumours.
5. HIV.
6. MS (can cause UMN too).
7. Diabetes Mellitus.

Question 16

Aetiology of Unilateral Facial Nerve Palsy - UMN.

Answer 16

Stroke.

Question 17

How do UMN and LMN lesions of the Facial Nerve differ?

Answer 17

1. UMN - spares upper face i.e. forehead.

2. LMN - affects all facial muscles.