The term synkinesis means “simultaneous movement” and is a form of facial paralysis. When the facial nerve is damaged, nerve branches can, in effect, be miswired either from faulty regeneration or when being sewn together to repair nerve damage.
Facial nerve fibers which reconnect to the wrong nerve groups can trigger involuntary and unwanted muscle movement. As a result, separate muscle groups which would normally function independently will move simultaneously. For example, a person smiles, and the eye on the affected side of the face will also close involuntarily. This most common manifestation of synkinesis is often referred to as ocular-oral synkinesis.
Functionally, synkinesis can cause limitations or difficulties in performing such activities as eating and drinking, or smiling. Social stigma and self-esteem issues are also significant problems resulting from the effects of synkinetic paralysis.
Treatment for Synkinetic Paralysis
Therapeutic modalities used in the treatment of synkinetic paralysis include three basic methods:
- Facial neuromuscular retraining – physical therapy is used to retrain the facial muscles and to decrease unwanted facial muscle movement, while increasing desired movement. Massaging and stretching of overactive muscles, with a focus on coordination of proper muscle movement. Mirror biofeedback may also be used.
- Botox – botulinum toxin type A (BTX-A) – is isolated from the bacterium Clostridium Botulinum – The medication is injected with fine needles and blocks the release of neurotransmitters at nerve endings, thus preventing muscle contraction. Common areas of treatment are the eye muscles (orbicularis oculi), chin dimpling(mentalis) and neck muscles(platysma). We also use Botox in the opposite normal muscles to balance the face and create symmetry. This is an office-based procedure which is completely reversible, has minimal risk, and lasts up to 3-4 months.
- Surgery – Selective nerve transection (selective neurectomy) of synkinesis is a minimally invasive procedure for patients who are resistant to therapy and Botox. The eye has numerous nerve branches which give it movement. In cases where patients are not responding to therapy or chemodenervation (Botox), one or more of these branches may be cut to permanently to relax the over-closure of the eye muscles. Also, if the neck muscles are a source of constant tightness, a slip of superficial neck (platysma) muscle may be removed permanently with no functional deficit.
- Muscle transfer: In some cases, muscle from another part of the body is used to reanimate the smile.
- Often times, a combination of therapies will be used.