19 - Bell’s palsy

What are the different types of facial palsy?

Central facial nerve palsy: Lower facial muscles are paralyzed, Upper are ok. Peripheral facial nerve palsy: One side is completely paralyzed.

How can we examine the facial nerve?

Ask the patient to smile & look for asymmetry Ask the patient to close his eyes. look for lagophthalamos (inability to close his eye completely) & inability to wrinkle his forehead. Ask the patient to blink frequently, notice any slowness of the closing phase compared to the contralateral side Examine bell' phenomenon: hold the upper eyelids, and ask the patient to close his eyes. Bell's phenomenon is more evident (due to lagophthalmos)

What can be the etiology of peripheral facial nerve palsy?

Idiopathic (= Bell's palsy) Infection VZV (herpes zoster oticus/Ramsay Hunt syndrome) Lyme disease Trauma (involving pyramidal bone) Parotid tumor Brainstem stroke (involving facial nucleus)

How do we treat Bells palsy?

In most cases Bell's palsy resolves completely in a few weeks without treatment. Steroids hasten the resolution if given within the first 3 days of symptoms. Acyclovir can be used if viral etiology is suspected. To prevent atrophy the patient should do physiotherapy of the face. To prevent keratitis, artificial eye drops must be used to prevent dry eyes if the patient can't close the eye completely.

What are the functions of the facial nerve?

Motor: stapedius muscle in the ears & facial muscles Autonomic efferent: fibers to the lacrimal gland & salivary glands Sensory: taste from the anterior two-thirds of the tongue & parts of the tympanic membrane & external auricular canal.

What is Bells palsy?

Peripheral facial palsy is a peripheral lesion of the facial nerve. In the cases where this lesion is idiopathic, the condition is called Bell's palsy. Bell's palsy is caused by idiopathic inflammation of CN VII in the facial canal. It might be due to viral infection, especially HSV.

What are the clinical presentation of Bells palsy?

Symptoms of peripheral facial palsy are ipsilateral to the lesion and affect both the lower and upper half of the face. Symptoms include: Motor symptoms Frowning, eye-closing, blinking is impaired Inability to close the eye Drooping corner of mouth Disappearance of nasolabial fold Pain behind the ear Hyperacusis Abnormal lacrimation Abnormal taste

How can we diagnose Bells palsy?

To evaluate for the motor symptoms, ask the patient to grin with teeth, close their eyes, and wrinkle the forehead. The tympanic membrane and ear canal should be evaluated for herpes blister by otoscope. If peripheral facial palsy is the only symptom, Bell's palsy is assumed, and no further investigation is needed. If other symptoms are present, investigate with MRI or LP to look for other causes.