What Is Synkinesis? Understanding Possible Treatment Approaches

Woman experiencing facial palsy (MODEL) pointing to her chin.

Following a period of temporary facial paralysis, many men and women may find that the affected facial nerves have recovered, but lingering asymmetry and involuntary muscle movements may persist. This condition, known as synkinesis, results from a miscommunication between the facial muscles and nerves.

What is synkinesis? If you or a loved one are facing this diagnosis, this blog post will help you understand more about this condition and what treatment options are available.

Understanding Synkinesis 

Synkinesis, also known as Post Paralysis Facial Synkinesis (PPFS), almost always develops after experiencing flaccid facial paralysis, which immobilizes all or part of the face. This type of paralysis can result from:

After a while, your facial nerves may begin to recover but don’t quite return to normal. This is thought to be a result of the regenerating axons (the sub-units of the nerve) not reconnecting with their specific muscles as accurately as they should.

These axons can then become hyper-excitable. The increased sensitivity often leads to the nerves sending signals to the wrong places in your face, resulting in unintended muscle movements.

3 Common Findings in Synkinesis Patients 

This “miswiring” between the nerves and the muscles manifests in nearly all synkinesis patients as the following:

#1 Involuntary Movements Occurring Alongside Intentional Ones

A common sign of synkinesis is when making voluntary facial movements tends to trigger involuntary movements in other parts of the face. Think of it like closing your eyes uncontrollably whenever you smile or eat.

#2 Facial Muscle Hyperactivity and Hypertonicity at Baseline

Most synkinesis patients will also display increased muscular tension (hypertonicity) and activity (hyperactivity), even when the face is at rest. Think of it as your eye being tighter on one side of the face versus the other, leading to facial asymmetry and a near-permanent squint.

#3 Simultaneous Activation of Facial Muscles With Opposing Activity

In this common synkinesis symptom, two sets of facial muscles are contracting at the same time, even though they should be doing opposite things. Think of it like trying to smile, but the corner of your mouth pulls downward at the same time.

What Is Not Common in Synkinesis Patients 

Although involuntary motion, increased baseline muscle hypertonicity, and simultaneous activation of opposing facial muscles are the hallmarks of synkinesis, patients will often differ in their symptoms, appearances, and priorities.

Some patients will complain of tightness around the eye, the midface, or the neck as a main concern, while others will express concern about the inability to smile effectively or speak. Some patients bite their lips or inner cheeks, and others may have difficulty eating. The brow or lips will be elevated for some and depressed for others, and so on and so forth.

Therefore, it is important to recognize that although patients with synkinesis have many common attributes and overlapping goals, each patient is unique and has individual needs and challenges. 

The Goals of Synkinesis Treatments

Synkinesis treatments aim to restore facial balance and function. This is usually done through a combination of surgery, physical therapy, and botulinum toxin A (BOTOX®). The reason for using multiple modalities of treatment is that no one strategy can address all the problems created by synkinesis. In fact, when applied together, they have a synergistic effect.

This is why BOTOX is used for a mild to moderate weakening of certain facial muscles, surgery is used when more permanent removal of restricting forces is required, and physical therapy is needed to stretch and temporarily relax certain muscles while teaching the patient to become less self-aware and overcome avoidance habits that they may develop.

Before and 3 months after a lower lip myectomy.
Before & After Lower Lip Myectomy
Before and 7 years after nerve transfers and cross facial nerve grafts for smile and eye reanimation.
Before & After Lower Lip Myectomy

What Types of Surgery Are Used for Synkinesis?

Surgical options for synkinesis usually entail a combination of selective neurectomies and selective myectomies.

What Are Selective Neurectomies?

Selective neurectomies can be defined as selectively removing segments of the facial nerve branches that cause some of the abnormal facial movements, muscle hypertonicity, and activation of antagonistic muscles.

In doing so, the spastic (hypertonic) muscles are weakened, which reduces the abnormal spasticity of the affected muscles while restoring more normal function to the other muscles. Patients will frequently have improved muscle coordination and function and also report less tension in the midface and the neck.

The incisions needed to perform selective neurectomies are exactly the same as I use for facelifts. They extend before the ear and then behind the ear in the hairline and are barely seen several months after surgery. Recovery is quick, and the majority of patients usually experience minimal bruising in the first two weeks after surgery. Most patients can go home the same day unless additional procedures are performed simultaneously. 

What Are Selective Myectomies? 

Selective myectomies involve removing or cutting a facial (mimetic) muscle. The objective is very similar to selective neurectomies, except the effect is localized to a more specific area where the muscle is targeted.

The most common muscle that is targeted is the Depressor Anguli Muscle (DOA), which often inhibits the smile. A selective myectomy in this area can help patients elevate the corner of the mouth.

This procedure entails an incision from inside the mouth and can be performed as an outpatient procedure. Patients are asked to avoid eating any sharp or crunchy foods for a week until the incision heals and to maintain good oral hygiene during this period. 

Before and 2 months after a lower lip myectomy.
Before & After BOTOX injections for blepharospasm (eyelid twitching)
Before and 4 months after a lower lip myectomy.
Before & After BOTOX injections for blepharospasm (eyelid twitching)
Before and 2 months after lower lip myectomy.
Before & After BOTOX injections for blepharospasm (eyelid twitching)

Why Is BOTOX Needed To Treat Synkinesis?

BOTOX may have several important roles in treating synkinesis. First, it is used in areas where surgery can be less effective due to the innervation patterns of certain muscles or when surgery may be a riskier option. One such area is around the eye. If surgery is too aggressive around the ocular nerves, there is a small risk that a patient may have difficulty closing the eye. This is a rare complication but may theoretically occur.

Therefore, using BOTOX around the eye muscles can be very helpful since the correct amount for each patient may be calculated after several sessions, and the effects are always reversible. Secondly, BOTOX is a very useful tool for patients who haven’t decided whether or not they want to proceed with surgery yet.

Will I Need Repeated BOTOX Injections? 

Since the effects of BOTOX are temporary, they provide patients an opportunity to “preview” what surgery might provide for certain aspects of synkinesis. This also allows patients and surgeons alike to get familiar with each other and form a more effective team.

However, it is important to understand that the improvements made by BOTOX tend to last an average of 3 months and will need to be repeated to preserve your results.  

Physical Therapy for Synkinesis 

Facial nerve physical therapy also has an important part to play in the treatment of synkinesis. Certain exercises, which include stretching or massaging the muscles, may provide temporary relief to symptoms. Exercises that emphasize using certain groups of muscles effectively (e.g., smiling from the cheeks) while diminishing the excessive use of others are also helpful. Example exercises can be found on the Facial Palsy UK website.

Perhaps one of the most important things to learn in physical therapy, however, is to be less self-aware. Patients frequently develop certain habits of avoidance, such as not smiling because of facial asymmetry or inadvertent eye closure, which makes recovery from surgery less effective.

The Paradox of Self-Awareness

The best results are often observed in patients who simply speak and laugh during a natural conversation versus when they are asked to smile. This occurs because when patients are asked to perform the task of smiling, they will often revert to preconceived notions about what they should do rather than simply doing it without thinking about it.

It is often helpful for patients to see candid photos or videos of themselves taken in a time of laughter and happiness. These objective photos will often provide patients insight into what they can do when they are not trying too hard to do it. 

In Summary 

As in every situation in facial palsy, good teamwork between the facial palsy surgeon and the patient is the key element for success. This starts with understanding the problems, defining the goals, and developing an individualized treatment strategy to achieve happiness and improved well-being.  

You can read more about making decisions about your synkinesis treatments in this related blog post. If you are ready to take the next step in discussing your surgical and nonsurgical options, please request a consultation or call us at (214) 645-2353 to get started.

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