Treatments for FP

If there hasn’t been a full recovery of facial movement within three months, then other treatment options need to be considered to help support the movement of the weakened facial muscles.  If not already done, this is the point at which patients should be referred to someone with experience in managing facial palsy.  After around 18-24 months of facial paralysis, the paralysed facial muscles permanently loose the ability to move again regardless of whether the nerves grown back to the muscles or not.

A large number of options are available and the exact choice depends on the severity of the facial palsy, patient preference and the part of the face being treated.  Below sets out the common treatment options available.

Eyebrow:

Paralysis of the forehead muscles can cause the eyebrow to sag downwards towards the eye.  Not only can this affect the overall appearance of the face, but it can also block the peripheral vision of that eye.

The most common treatment option for the eyebrow is to lift the eyebrow back up into a position that is symmetrical to the other side.  This is called a browlift.  A number of different techniques exist to achieve this, but commonly this is done by making a cut above the eyebrow itself, removing a small paddle of skin and then securing the eyebrow into its new position.   It should be noted that this won’t restore movement in the eyebrow.  A browlift is, therefore, often combined with Botox treatments to the healthy forehead on the opposite side to take away dynamic movement and wrinkles on the healthy side to achieve better overall symmetry.

Eyelids:

The two key changes around the eye in long-standing facial weakness are an inability to lower the upper eyelid and a loss of strength in the lower eyelid causing it to sag down away from the eyeball itself.  Combined, this makes it difficult to close the eye.  Surgery can be used to try and correct these problems.

In the upper eyelid, small gold or platinum weight can be placed underneath the skin to help lower the upper eyelid when closing the eye.  This is usually done through a cut made in a natural skin crease of the upper eyelid.  It should be noted that, although this helps lower the lid when voluntarily closing the eye, it doesn’t tend to help eye closure when blinking.

In the lower eyelid, the loss of muscle strength causes the lid to hang down and away from the eyeball.  This contributes to watering and dryness of the eye.  Surgery can be used to tighten and support the weakened lower eyelid and it usually performed through cuts made around the lower eyelid margin and inside the lower eyelid itself.  Occasionally the skin on the outer surface of the lower eyelid can have shrunken down over time.  In this situation a skin graft may be required to lift the lower eyelid back into an acceptable position.  

It should be noted that eye watering often remains an ongoing problem even after the upper and lower eyelid have been addressed.  This is thought to be due to the tear drainage system lacking the muscle pump mechanism that normally pumps tears from the eye down into the nose.

Smile/mouth:

Many different options exist to support the mouth and, with some options, restore a smile-type movement.  Broadly speaking, these can be split into dynamic and static options.  Dynamic options aim to bring back active movement to the smile, whereas static options simply aim to support the corner of the mouth.

Static options – This typically involves taking a strip of muscle lining (fascia lata) from the thigh.  This is then used as an internal sling to support the corner of the mouth.  The fascia lata sling is placed under the skin via a cut made in front of the ear, as well as some additional cuts made around the lips and in the natural fold between the nose and mouth (the nasolabial fold).   Over a number of years, the fascia lata sling can stretch and may need to be retightened.

Dynamic options – In situations where the facial muscles are no longer able to function, new healthy muscle needs to be recruited from elsewhere.  The common sites include muscles taken from the temple (temporalis muscle), inner thigh (gracilis muscle), chest (pectoralis minor muscle), or back (latissimus dorsi muscle).  

The temporalis muscle typically brings with it its own nerve and blood supply and is slid downwards so that the tendon can be connected to the corner of the mouth (lengthening temporalis myoplasty).  The other muscles mentioned need to be connected up to nerves and blood vessels in the face for them to generate movement.  

In some circumstances, this may need to be done across two operations with the first operation aimed at placing a nerve graft from the healthy unaffected side over towards the paralysed side.  A period of around six months is then given to allow the new nerve fibres to grow along the nerve graft towards the paralysed side of the face.  This procedure is called a cross-facial nerve graft operation.  In most cases, a nerve is taken from the lower leg and results in some loss of sensation to the outer part of the foot.

It is important to note that these muscles restore a single direction of movement.  As a result, the smile is not as natural in appearance to the healthy side where a complex interplay of 12-15 muscles brings about a natural smile.

Lower lip:

Many people, when they smile, have some descent of the lower lip.  This doesn’t occur on the paralysed side in patients with facial palsy.  

The two main treatment options for this include Botox treatment to paralyse the healthy side’s lower lip depressor muscles and surgery to try and restore some lower lip descent movement on the paralysed side.  Botox works by removing the lower lip depression on the unaffected side so that both sides don’t descend upon smiling.  For a more permanent result, procedures can be performed to surgically divide the muscle that causes descent on the healthy side.

To try and restore lower lip descent on the paralysed side, a muscle can be taken from the upper neck and transferred to the lower lip.  This is called an anterior belly of digastric muscle transfer.  

Nerve transfers and grafts:

In patients with facial palsy that are not showing any signs of movement recovery but are within 12-18 months of the onset of the facial weakness, there are options available to restore electrical signals to the paralysed facial muscles to bring about movement again.  These are called nerve transfers or nerve grafts.  

The common nerve transfers include taking a nerve involved in stimulating a chewing muscle (the masseteric nerve), or a part of a nerve involved in moving the tongue (the hypoglossal nerve).  These are then connected up to the non-functioning facial nerve. Nerve fibres from these nerves will then grow into the paralysed facial muscles.  It is important to note that these movements are not coordinated with movements on the other side and there is a large amount of re-learning that needs to be done to get the best possible function from these procedures.

A nerve graft usually involves running a cable of nerve from a nerve branch on the healthy side of the face to the paralysed muscles on the opposite side of the face.  This is called a cross-facial nerve graft.  The nerve graft is usually taken from the leg.  Although this gives the best chance of restoring movement that is coordinated to the healthy side of the face, it relies on the patient having a good capacity to grow and regenerate nerve fibres.  Age, smoking and other medical problems can impact this.