What is selective neurolysis surgery?
Selective neurolysis or modified selective neurectomy is the contemporary cutting-edge surgical option for patients living with non-flaccid facial paralysis and synkinesis. Non-flaccid facial paralysis and synkinesis arise from incomplete recovery of the facial nerve following Bellsโ palsy, Ramsay-Hunt syndrome, skull base tumor surgery, traumatic injury and other reversible causes of facial paralysis.
Following facial nerve injury, facial nerve regeneration my lead to erroneous wiring of the facial muscles. Facial nerve branching in the face is highly variable and the nerve splits into multiple branches to innervate facial muscles. There is also person to person variability in facial muscle innervation, which allows us to have multiple and unique facial expressions. In fact, person to person variability is responsible for your individuality with patterns of facial expression being genetically predetermined.
The miswiring of the facial nerve during regeneration is currently thought to produce synkinesis. The hallmark of synkinesis is undesired activation of counterproductive muscles during facial expressions. For example, during a smile there is activation of both smile and frown muscles leading to net โfrozenโ appearance. Some patients describe this as inability to smile. In patients with synkinesis, there is erroneous activation of facial muscles that would not normally be activated during a particular intended movement. Since our facial nerve organization is unique, there is individual variability in the pattern of synkinesis. This pattern takes 12-18 months to develop when facial movements begins to return following a recovery from flaccid paralysis.
For years the marker of successful nerve recovery was return of any facial movement even if it was counterproductive. Many approaches have been described in order to manage synkinesis. The mainstay of treatment is botulinum toxin treatment and facial physiotherapy otherwise known as neuromuscular retraining. Currently, this is the standard treatment for synkinesis and non-flaccid facial paralysis. Selective neurolysis surgery is aimed at improving the smile, where we selectively reduce the activity of miswiring nerves in order to release the smile movement and separate it from frown movement.
When do I need selective neurolysis surgery?
Selective neurolysis surgery is an option for patients living with synkinesis, who want to improve their smile. Dr. Araslanova offers selective neurolysis treatment to patients who achieved good results with botulinum toxin and facial physiotherapy and are now ready to make smile changes more permanent. Selective neurolysis is generally not effective for the upper face. Multiple studies showed that selectively neurolysis of nerves innervating eye muscles leads to recurrence of symptoms in 1-2 years. Therefore, botulinum toxin is used for the upper face. Surgical options like myotomies and myectomies where a strip of muscle is removed is an option in select patients.
How do I prepare for selective neurolysis surgery?
Prior to selective neurolysis surgery, all chemodenervation treatments with botulinum toxin should have warned off (Botox, Xeomin, Dysport, Juveau, Daxxify etc). This is important because we use facial nerve monitoring that uses nerve signals to the muscles in order to identify nerves the activity of which should be reduced. Botulinum toxin will hinder effective monitoring, so sufficient time should be allowed before surgery is pursued to ensure all the effect has worn off. You should also plan for postoperative facial physiotherapy, which is crucial in achieving your smile goals following selective neurolysis surgery. Facial physiotherapist is instrumental in optimizing your result.
What happens during selective neurolysis surgery?
Patients are taken in to the operating room and surgery is performed under general anesthesia. Facial nerve monitoring system to carefully monitor the facial nerve to ensure its integrity. Facial monitoring is used to identify and confirm functions of each facial nerve branches. There is significant variability in number and pattern of branching of nerves responsible for facial expressions including smile and frown.
The incision is made in natural facial grooves, similar to a facelift incision. There are usually multiple smile and frown branches, so a surgeon will carefully and meticulously identify each branch contributing to these movements. Once all branches are identified with the use of direct stimulation, decisions are made about activity of which nerves should be reduced. This is the longest part of the operation, because the pattern is customized to each patientโs face. The incision is then closed. If desired by the patient, symmetrical facial repositioning to match the unaffected side can be pursued and the results are similar to a facelift. You will see some improvement in the movement immediately after surgery, however, final results will take 6-12 months to develop with targeted facial physiotherapy.
What are the risks of selective neurolysis surgery?
It is important to understand the purpose of selective neurolysis surgery is to improve smile and to reduce the need for botulinum toxin in the lower face. Selective neurolysis is not performed on the upper face. Long term studies show consistently that synkinesis of the eyelid muscles recurs after nerve activity is reduced and these results do not last as long as smile improvements. Risks of worsening of movement and decreased symmetry are possible. Some patients develop transient weakness when using straws to drink and with certain movements. Your surgeon will discuss this in detail.
The general risks of any facial surgery include scarring, bleeding, bruising, infection, fluid or saliva collections under the skin, injury to nerves, donor site issues, numbness, the need for additional surgery, hair loss, chronic pain, numbness, temporary or permanent loss of facial movement on the functional side effects of general anesthesia. Preparing for surgery and following your doctorโs instructions are useful to help minimize risks.