The term facial palsy generally refers to weakness of the facial muscles, mainly resulting from temporary or permanent damage to the facial nerve.
When a facial nerve is either non-functioning or missing, the muscles in the face do not receive the necessary signals in order to function properly. This results in paralysis of the affected part of the face, which can affect movement of the eye(s) and/or the mouth, as well as other areas.
There are different degrees of facial paralysis: sometimes only the lower half of the face is affected, sometimes one whole side of the face is affected and in some cases both sides of the face are affected.
How do the facial nerves work?
Each side of the face has its own facial nerve, so damaging the left facial nerve will only affect the left side of the face, and vice versa. Each nerve starts at the brain and enters the face to the front of the ear where it then divides into five separate branches. These branches supply the muscles which are used for facial expression. Tears, saliva production and taste are also controlled by the facial nerve in different ways.
What causes facial palsy?
Although the most commonly known cause of facial paralysis is Bell’s palsy, there are actually many different causes of facial palsy, and treatment and prognosis vary greatly depending on the cause. Some of the main causes of facial palsy are listed below:
- Viral infections such as Bell’s palsy and Ramsay Hunt syndrome.
- Surgical causes: for example during removal of acoustic neuroma or facial nerve tumour, or when operating on the parotid gland.
- Bacterial causes such as Lyme disease or following a middle ear infection.
- Neurological conditions such as Neurofibromatosis 2, or Guillain-Barré syndrome.
- Traumatic injury such as fractures to the brain, skull or face.
- Birth trauma: for example caused by forceps or facial presentation delivery.
- Congenital conditions such as an abnormal development of the facial nerve or muscle in the womb.
- Rare genetic syndromes such as Moebius syndrome or CHARGE syndrome.
- Stroke: although a stroke can cause facial palsy it is slightly different in that the problems are not caused by direct damage to the facial nerve. The paralysis in this case is caused by brain damage and the messages not being transferred properly to the facial nerve.
What functions do the facial muscles perform?
- Raising the eyebrows (frontalis)
- Closing the eyes (orbicularis oculi)
- Frowning (corrugator)
- Open mouth smiling (zygomaticus)
- Closed mouth smiling (risorius)
- Pouting (orbicularis oris)
- Lifting top lip (levator labii)
- Pulling lower lip down (depressor labii)
- Sticking bottom lip out (mentalis)
- Pulling jaw and corners of mouth gently down (platysma)
- Wrinkling nose (procerus/nasalis)
There are many physical issues associated with facial paralysis which are not always immediately obvious to others.
A range of facial expressions are used to communicate with people every day, this is known as non-verbal communication and many expressions are used subconsciously. People with facial palsy find normally simple actions difficult, such as smiling, scowling, winking and pouting. Being self-conscious about using facial expressions is a barrier to communication; people with facial palsy may prevent themselves from smiling to try and hide their asymmetry, giving the impression to others that they are unfriendly.
People with facial palsy may have problems closing one or both eyes. The reduced or absent blink mechanism results in dry eye problems, a very painful condition. The natural moisture in the eye is important for vision and when an eye is too dry the vision can become blurred. When an eye does not close properly it makes some aspects of life much more difficult, such as showering and sleeping. Often when an eye becomes too dry it reacts by excessively watering and may look red and sore, making the person feel even more self-conscious.
When a person has facial palsy, the stapedius muscle in the ear can be affected, causing sounds to seem louder on the affected side. The stapedius is a tiny muscle that helps control the sounds reaching the inner ear from outside, and protects it from high noise levels, for example the volume of your own voice.
Eating and drinking
When the facial muscles are not working correctly it can be harder to eat and drink on the affected side. There is a weakness of the cheek and lip seal, which makes it difficult to retain food and drink, and to chew. Simple things like eating an apple become difficult. Food can also collect in the cheek and be difficult to remove. There is often a tendency to bite the inside of the cheek or lip.
Saliva plays an important role in protecting the teeth and gums from decay and disease. Facial palsy can result in reduced saliva production and therefore make teeth more vulnerable to decay. For some people, having facial palsy can make brushing teeth more difficult, and it can also impact on how well dentures fit.
Damage to the facial nerve itself does not typically cause pain, but some causes of facial paralysis can be accompanied by painful symptoms in varying degrees. Pain associated with Ramsay Hunt syndrome can be very distressing, and Bell’s palsy can also result in some pain or tenderness in or around the ear.
The facial nerve controls movement of the lips and is also responsible for maintaining good muscle tone in the cheeks. If the facial nerve is damaged the lips can become weak and cheek muscle tone reduced or lost. As a result it may feel more difficult to speak, the person’s speech become unclear or they may feel that they sound different to what they used to sound like.
When the facial nerve is injured, hemifacial spasm can occur. This type of spasm causes muscles on one side of the face to contract; the first symptoms are typically a nerve twitching in the face which gradually increases throughout the muscles in the lower face.
People with facial palsy may experience synkinesis during the later stages of recovery. It is a medical term that means ‘unwanted movement’, where different parts of the face move together in unexpected ways. For example, an attempt to smile may result in an eye closing at the same time. Affected muscles have to be re-taught when to move and when to stay relaxed, and various facial exercises have to be practised over and over again.
- Manual Therapy
- Dry needling
- Low Level Laser
- Exercise Program