Facial Nerve Injury and Rehabilitation
The expressive (mimetic) musculature of the human face is controlled by a the delicate and intricate branches of a single nerve – the facial nerve. This nerve emerges from the skull deep in the side of the face, near the ear canal, and then sends tiny, interconnected branches throughout the face.
Damage to the facial nerve may cause imbalance of the face at rest (facial droop) as well as distorted or asymmetric facial expressions (e.g., a crooked smile, a quizzical look, or grimacing while talking, laughing, or attempting to smile, etc.). Functionally, facial nerve injury may affect chewing and swallowing (oral incompetence, i.e., spilling fluid while drinking), and can lead to nasal obstruction (difficulty breathing though half of the nose), corneal injury (exposure keratitis), poor speech enunciation and intelligibility, and significant communication problems. Weakness of the circular muscles around the eye is particularly problematic, as this causes incomplete eye closure (lagopthalmos), excessive corneal exposure and tearing, and even blindness if left untreated. Paralysis of the small nasal muscles cause collapse of the nostrils during breathing and a sensation of nasal congestion that is not relieved by medications. Last but certainly not least, many people are severely mentally and emotionally affected by facial paralysis, often feeling ashamed or embarrassed and losing confidence in themselves – which only makes their adjustment and recovery more difficult.
In adults, most cases of facial paralysis are idiopathic (unknown origin), though some can eventually be linked to a viral infection (typically Herpes Simplex Virus [HSV] or Varicella Zoster Virus [VZV], i.e., chicken pox). These cases are generally referred to as Bell’s Palsy. Other cases are related to stroke (cerebrovascular accident or “brain attack”) or systemic illness, such as diabetes or autoimmune disease. Facial paralysis is also, sadly, associated with pregnancy in rare cases. In children, facial paralysis most commonly occurs from trauma during birth, though it can also result from rare genetic abnormalities or syndromes. In some cases, the facial nerve may not function after brain tumor resection. Adults may experience complete or partial paralysis following an episode of Bell’s Palsy, with brainstem tumors (e.g., acoustic neuroma), or following blunt or penetrating traumatic injury.
In the upper third of the face, patients will be unable to wrinkle one side of their forehead. and the brow drops over the eye often blocking vision. For this problem, Dr. Ransom performs a brow lift. Depending on severity, an endoscopic browlift (forehead lift, minimally-invasive, using a tiny incision and a camera), a pre-tricheal browlift (using an incision camouflaged in the hairline), or a direct browlift (typically reserved for bald patients) may be selected. The brow lift tends to reposition the droopy eyebrow and droopy forehead at a more even position with the other side; this improves facial symmetry as well as the patient’s vision. Finally, in cases where the brow is not very heavy or ptotic (drooping), there is an option to use Botox (botulinum toxin) to even out the two brows, rather than elevating the injured side of the eyebrow region.
For the middle third of the face, complex surgical treatments of the eyelids and nose may be required. The most important concern Dr. Ransom has with facial paralysis is the protective function of our facial muscles. Without the blink reflex and the ability to close the eye the cornea can become dried out and injured (exposure keratitis). This can significantly damage vision and lead to blindness in severe cases. A gold weight can be placed in the upper eyelid through a partial blepharoplasty (eyelid surgery) incision. With a properly selected gold weight, when the patient rests the weakened eyelid then the weight will closes the eyelid using gravity.
Since a different nerve and muscle (leavtor palpebrae muscle) opens the eye the ability to open the eye is still present. Gold is used because it is very dense and non-reactive (well-tolerated by most patients). If the lower eyelid is too loose (since the muscle is not working to hold it tight), the lateral canthus (corner of the eye) must be altered. This involves a canthoplasty to reposition the lower eyelid and a tarsal strip procedure to shorten and tighten the lower lid sling. This improves both function and cosmetic appearance, by making the eye shape more similar to the non-paralyzed side.
For the nose, collapse of the sidewall and nasal cartilages (internal and external nasal valve regions) results in restricted airflow through half the nose. This can limit physical activity and lead to snoring or even voice changes. Reconstruction is performed via a functional rhinoplasty approach and involves repair of the nasal valve regions. In severe cases, a suspension procedure is required for the upper and lower lateral cartilages which support the nasal vestibule (nostril) and ala (wing). Occasionally, these techniques require structural cartilage grafting. Dr. Ransom always uses the patient own tissue, generally borrowing cartilage from the nasal septum or the bowl of the non-dominant ear.
In the lower face, repositioning of the cheeks and the corner of the mouth can significantly improve the overall balance of the face and make the facial nerve deficit much less visible to the casual observer. In addition, some reconstructive procedures can restore a minimal amount of movement to the corner of the mouth on the injured side. Perhaps the most devastating loss for Bell’s palsy patients is the ability to smile. This is especially heartbreaking to younger patients and their families who are embarrassed and isolated by the loss of communication skills.
The patient’s self-esteem can be severely impacted by peer criticism. The mouth must be able to close in order to talk, prevent drooling, whistle, pucker, and open in order to communicate, smile, or frown, etc.
Dr. Ransom uses a variety of methods for repairing facial nerve paralysis around the mouth. In some cases this involves a unilateral (one side) facelift. For more severe issues, regional muscle transfers from the adjacent scalp (temporalis muscle) or neck (digastric muscle) may be used to balance voluntary facial expression and restore a more even smile. The active method of doing this is to transfer a muscle from the chewing muscles of the side of the face down to help elevate the corner of the mouth. The newest most revolutionary procedure for this today is the temporalis tendon transfer procedurewhich transfers a small tendon from one of the muscles used to chew to help the corner of the mouth move. This is all done through a small incision inside the mouth or in the cheek fold, so that there are minimal or no visible scars.
Dr. Ransom’s goal in every case is a more symmetric and aesthetically pleasing face, as well as enhancement of facial function and protection of vital structures. Although there are no absolute guarantees, the procedures presented have been very successful in restoring facial balance and improving expression. As you might expect, these procedures enhance the quality of life for children and adult patients alike.
Please note that all patients are different and individual healing times and results may vary. The statements regarding procedures and recovery made here are general rules.