Facial paralysis — facial palsy

Facial palsy is paralysis of part of the face caused by non-functioning of the facial nerve that controls the muscles, especially around the eye and to the mouth. The facial nerve is also called the seventh cranial nerve.

It has a complex course from the brain stem to reach the muscles governing facial expression. It controls the muscles that lift the eyebrows, the muscles that close the eyelids, the muscles of the cheek and around the mouth.

Facial palsy can be congenital — present at birth or shortly after — or acquired, possibly following a viral illness or through no obvious cause. Under these circumstances, it is referred to as Bell's palsy. Sometimes a tumour can compress and damage the nerve. Other causes include serious infections and skull fracture.

Facial paralysis usually affects half the face, which flattens and loses forehead wrinkles and horizontal lines. There is also a droopy eyebrow, difficulty closing the eye, an inability to whistle and the corner of the mouth is pulled down.

The effects on the eyes are particularly significant. The upper eyelid can be a little too high and the lower eyelid can sag and turn outward (ectropion), resulting in a watering eye, inability to close the eye and exposure or drying of the cornea. The eye can become red, vision can blur and sight is occasionally affected by ulceration and scarring (exposure keratopathy).

More unusual problems include losing the use of the nerve (the trigeminal, or fifth cranial, nerve) that controls sensation in the eye. This usually happens as a result of surgery on a large, benign brain tumour (an acoustic neuroma), which has affected both the facial nerve to the muscles and the sensory nerve to the front of the eye.

Rarely, patients may suffer a lack of sensation on the surface of the eye (cornea), so that they cannot feel dryness, foreign bodies or injuries to the surface of the eye. This puts them at risk of developing a corneal ulcer and suffering severe damage to their sight.

Crocodile tears are another rare consequence of facial nerve paralysis. They occur when the damaged nerve tries to grow back along its old pathway but goes instead to the tear (lacrimal) gland and to the muscles of the jaw. This results in embarrassing tears when the patients chews.

Other consequences of a nerve regrowing in the wrong direction include closing of the eyelid and muscle spasms in the eyelid, cheek and around the mouth.

Facial palsy with previous eyelid surgery to lower eyelid and the inner corner of the eyelid — see rounded appearance of the eyelids. Redness of the eye comes from soreness caused by incomplete eyelid closure and outward-turning lower eyelid

After surgery to insert lower eyelid fascial sling and a gold weight into the upper eyelid

Facial palsy showing incomplete left eyelid closure with lower eyelid turning inwards

Facial palsy showing incomplete left eyelid closure with lower eyelid turning inwards

Trial to calculate the weight needed for the gold implant

After surgery to insert lower eyelid fascial sling and a gold weight into the upper eyelid

Treatment

Most patients can be managed medically:

Surgery

If there are difficulties in protecting the eye from incomplete eyelid closure — which causes problems such as dry eyes, discomfort and/or affected eyesight — then surgery is an option. It can also improve facial symmetry and eyelid function and reduce eye watering.

Procedures include:

This is a tightening of the lower eyelid, which is shortened and re-attached a little higher to improve eyelid closure and comfort

This is the surgical closure of the outer portion of the eyelid to reduce the length of the eyelid that is open, decrease evaporation and improve coverage of the eye. It is not the best rehabilitative procedure and it has a poor cosmetic result. It can cause a blinkering effect to the vision towards the side where the surgery has taken place. It is therefore reserved for special cases and emergencies.

Stitches at the inner corner of the eye pull up the sagging lower eyelid. It usually takes place in conjunction with lower eyelid tightening, or a lower eyelid sling procedure where the lower eyelid is suspending in a hammock-like fashion from both inner and outer corners.

Placing a gold weight or thinner platinum chain in the upper eyelid can give a more animated expression and better closure of the upper eyelid, especially while blinking.

This is known as brow ptosis correction. There are several different procedures to improve the position of a drooping eyebrow. Some of them involve incisions above the eyebrow, while others are carried out via the forehead or small incisions in the scalp. Brow ptosis correction can be necessary as part of the rehabilitation in a patient with longstanding facial palsy.

The mid-face or cheek can be lifted to help improve the position of the lower lid. More extensive facelift-type surgery, with incisions in front of the ear and into the hairline, can improve the symmetry between the two sides of the face. A sling made of tissue from the patients leg (the fascia lata) or an inert strip of material can be used to help resuspend the mouth.

Occasionally, the front of the eye (cornea) becomes ulcerated and very painful, or the eye becomes red. This condition is known as exposure keratopathy with severe keratitis. Lubricants and other eye drops may not be enough to improve this condition, so it can be necessary to lower the upper eyelid temporarily.

This is done by giving a small injection of Botox underneath the upper eyelid, which temporarily paralyses the muscle that lifts the eyelid open and allows the eyelid to drop over the eye (protective ptosis) so that the keratitis or ulcer can heal. These injections can last up to three months and be repeated. Alternatively, surgery may be needed.

Botox can also be injected into the tear (lacrimal) gland to prevent crocodile tears and to deal with tics caused by the facial nerve regrowing in the wrong direction.

All procedures begin with a consultation. For full information about what to do before and after surgery, see Patient information.

Back to top