Information About the Field of Fascial Stretch Therapy (FST)
What is facial nerve palsy?
Facial nerve palsy refers to paralysis of the facial muscles as a result of damage to the responsible nerve. In this case, it is the facial nerve.
The medical term paresis refers to a partial paralysis of one or more muscles.
Facial nerve palsy may present in a number of different ways. For instance, patients may no longer be able to close their eyes properly, their face may contort when smiling or their speech may sound slurred.
Because of the diverse roles as well as the complicated anatomical pathway of the facial nerve, this heterogeneous clinical picture has already driven quite some medical students mad.
Its main function is to control the facial muscles. Medically, they are referred to as mimic muscles, allowing us to show a range of facial expressions.
Furthermore, the facial nerve regulates smaller glands of the nasal mucosa, the lacrimal glands and the sense of taste, along with saliva production and the tactile sensation.
Facial nerve palsy might come on suddenly and is often interpreted as a symptom of a stroke. In most cases, however, there are other factors responsible for this muscle disorder.
Symptoms associated with facial nerve palsy
The complex course and the many functions are why damage to the nerve can result in different symptoms based on the location of where it happens.
The so-called nucleus of the nerve, in other words the place from where the nerve cells extend their long nerve fibers to the various regions it supplies, is located in the brain stem. This nerve travels via a bony canal from the brain stem to the skull wall close to the ear and then branches out to the corresponding parts of the face. During its course, the nerve sends off various branches, all of which fulfill different functions.
The leading symptom of facial nerve palsy is flaccid paralysis of the facial muscles. This can be seen as a drooping eyelid, the absence of wrinkling of the forehead or the inability to blink, for example. Such limitations are particularly noticeable when the person is speaking.
The nerve also supplies many salivary glands, which can result in dryness of the eyes due to impaired lacrimal glands or a dry mouth, for example. It also plays a role in the taste sensation of the front two-thirds of the tongue, so this can also be impaired.
One branch of the facial nerve feeds minute muscles in the ear, which are primarily responsible for dampening very loud sounds for the ear. If damage occurs in this part of the nerve or prior to the branching, patients can be suffering from hyperacusis. This is when noises and sounds are experienced as unpleasantly loud.
Forms of facial nerve palsy
There are two types of facial nerve palsy, depending on the location of the nerve damage: central and peripheral.
Central facial nerve palsy
Central facial nerve palsy takes its name from the central damage to the nerve, in the so-called brainstem nucleus area. This is where the nerve originates. In most cases, this affects one side. Because the nerves cross to the opposite side during their course from the brain stem to the periphery, right facial nerve damage affects the left side of the face and vice versa.
There is also a difference in symptoms from peripheral facial nerve palsy. In this case, as the muscles above the eyelid are innervated by both hemispheres of the brain, paralysis appears in the facial muscles below the eyelid. Despite the fact that central facial nerve palsy is usually only temporary, it may be the symptom of a serious illness like a stroke. It is therefore strongly recommended that you consult a doctor immediately.
Peripheral facial nerve palsy
With peripheral facial nerve palsy, the damage only affects the peripheral part of the nerve. There are several locations at which the nerve is at risk of being compressed.
Peripheral facial nerve palsy represents a relatively common diagnosis and can express itself in a variety of symptoms. It typically differs from central facial nerve palsy in that it often affects the entire facial muscles of one side of the face, along with the eye and forehead muscles. Additionally, peripheral lesions of the right facial nerve also affect the right side of the face, with the same applying to left-sided lesions.
Causes: How can facial nerve palsy develop?
The most frequent form of one-sided facial nerve palsy accounts for around 50-65% of cases and is of unknown cause. It is also referred to as "Bell's palsy". The so-called idiopathic facial nerve palsy seems be equally common in both genders and different age groups.
It has not yet been possible to identify an exact cause. Most cases involve swelling of the nerve due to an irritating condition. A number of factors like stress, infections, pregnancy or a draft seem to contribute to the onset of this irritation, causing the nerve to tighten in the bone canal.
Usually, the paralysis is only one-sided and happens unexpectedly. But there alre also cases that present with signs like pain near the ear or sensory disturbances in the cheek. Patients may wake up in the morning with one side of the face paralyzed, which develops fully within about three days.
Peripheral facial nerve palsy can be the result of various diseases.
Hereditary diseases
A group of diseases in which facial nerve palsy may occur are hereditary diseases with genetic factors leading to the development of a clinical picture. These can include diseases such as Möbius syndrome, in which the facial paralysis appears during infancy. In these cases, some of the nerves, among them the facial nerve, are underdeveloped or do not fully function because of developmental disorders.
Melkersson-Rosenthal syndrome is another possible hereditary disease. It is a rare disease for which the precise cause is not known, but genetic factors are thought to be involved. It mainly affects patients from 20 to 40 years of age and is primarily noticed by swelling of the upper and/or lower lip, a wrinkled tongue and recurrent facial nerve palsies.
Infections
There are various infectious diseases that can lead to facial nerve palsy. The most common infection by far is Lyme disease. Facial nerve palsy is also sometimes preceded by an infection with the herpes zoster virus.
Lyme disease or borreliosis refers to a bacterial infectious disease which is transmitted by tick bites. The course of the disease varies greatly and takes place in different stages. In the advanced stage, the infection can spread to the facial nerve, resulting in unilateral facial paralysis.
One of the viral infections that can trigger this type of paresis is herpes zoster virus. This virus not only produces the classic chickenpox, but once reactivated it can also lead to a form of shingles (herpes zoster). A subform called herpes zoster oticus can affect, among other things, the facial nerve as it travels through the ear canal. The result is peripheral facial nerve palsy.
Other infectious diseases including rubella, mumps, polio and influenza can also lead to facial paralysis, as in all cases there is a risk of the infection spreading to the facial nerve. However, this type of nerve damage is usually only temporary.
Autoimmune diseases
Autoimmune diseases are characterized by the immune system attacking the body's own structures through various mechanisms. Some of them can trigger peripheral facial nerve palsy.
In this regard, sarcoidosis (Boeck's disease or Schaumann-Besnier's disease) and Guillain-Barré syndrome are the most well-known triggers of peripheral facial nerve palsy.
Sarcoidosis is a systemic disease that can cause inflammation of the parotid gland or lacrimal gland, among other things. In the course of the disease, this can damage the surrounding nerves.
Guillain-Barré syndrome entails inflammatory reactions of various nerve endings, which are then destroyed. The condition manifests itself in the form of various symptoms of paralysis. It usually begins in the legs and spreads throughout the body, so that facial paralysis is only a part of the clinical picture. However, the paralysis is not permanent, but regresses spontaneously over time.
Tumor diseases
Different tumor diseases can also lead to facial nerve palsy. The most frequent tumor is the acoustic neuroma.
It is a benign tumor that arises from cells of the nervous system. Its first symptoms are hearing and balance disorders resulting from impairment of the respective nerves. If left untreated, the symptoms can also spread to the facial nerve and damage it.
All tumors that are anatomically close to the ear and the main part of the nerve can ultimately be the cause of facial nerve palsy.
Central facial nerve palsy is usually due to diseases that affect the brain. They include tumors, cerebral infarction, brain injuries, polio or multiple sclerosis. As opposed to peripheral paresis, in central paresis usually an arm or a complete half of the body is also paralyzed.
How can a doctor diagnose facial paralysis?
Although an experienced doctor can usually identify one-sided facial paralysis just by looking at the patient, the diagnosis should follow a systematic approach.
The first step is to take a detailed medical history. It is particularly important to gather information on any previous illnesses, such as high blood pressure, and to date the onset of the first symptoms as accurately as possible. This interview and the following physical examination usually reveal a distinctive clinical presentation: the corner of the mouth is open, saliva is leaking, the speech seems difficult to understand and the eyelid closes only partially or not at all.
Once ruling out symptoms that point to an acutely dangerous illness and require immediate action, a blood sample is usually taken. The goal here is to rule out viral or bacterial infections.
The neurological examination assesses the functionality of the central and peripheral nerves. In the event of peripheral paralysis, it is important to localize the damage to the nerve. The degree of paralysis varies according to whether the nerve damage is inside or outside the skull: it may only be the facial muscles that are paralyzed or, if the damage is inside the skull, taste, sensation or salivation may also be impaired.
Facial nerve palsy can be divided into six grades according to its severity, with grade 1 meaning "no paralysis" and grade 6 "complete paralysis". It is particularly critical to determine grade 2 and grade 3 when making a diagnosis, as the patient's facial expression is normal but the nerve is already slightly damaged.
If peripheral damage is suspected, electromyography is performed. Using this method, it is possible to differentiate whether muscle paralysis is caused by damage to the muscle itself or by nerve damage.
To diagnose central facial nerve palsy, various imaging techniques such as MRI, CT or X-ray are employed to visualize the brain and skull so that possible injuries can be localized.
Therapy of facial nerve palsy: overview of the treatment options
Because of the diverse causes associated with facial paralysis, it is difficult to formulate a standardized treatment plan. Instead, the treating specialist should focus on the underlying clinical picture. Both medical and surgical treatment methods are available.
Facial nerve palsy due to a stroke requires immediate treatment in a specialized clinic: Occluded cerebral arteries must be opened immediately, cerebral bleeding stopped and increased intracranial pressure reduced as quickly as possible.
If the cause is a bacterial or viral infection, then antibacterial, antibiotic or antiviral medication is administered.
Bell's palsy, which is particularly common, has a very good chance of recovery even if left untreated. Around 60 percent of patients recover on their own. The remaining patients are usually treated with cortisone therapy to combat the inflammation of the nerves.
Drying of the eyes must also be prevented if the eyelids do not close. Ointments or night-time dressings are used here, for example.
Physiotherapy to train the facial muscles can also help patients.
Surgery may also be recommended in some cases. For example, depending on the extent of the nerve damage, reconstruction of the nerve or fusion of the fibers of the facial nerve with another nerve which is still functional can be carried out so that the muscles can be controlled and moved again.
In approximately 80 percent of such cases, the paralysis resolves, although the duration of the healing process heavily depends on the degree of severity.
Studies have shown that approximately two thirds of all patients with Bell's palsy recover completely within four months. About three quarters of all patients with complete facial nerve palsy report a very good recovery after about six months.
Late effects of the disease may include so-called "crocodile tears", which is involuntary tears when eating. It is not uncommon for the disease to recur.
Which exercises can improve facial paralysis and speed up the healing process?
A variety of exercises can relieve the symptoms of facial palsy and alleviate the suffering of patients. In particular, a combination of several therapy concepts from physiotherapy, speech therapy and occupational therapy is recommended.
The goal of the therapy is to relearn to control the facial muscles through the damaged nerves. Regular practice can help to prevent atrophy of the corresponding muscles. Atrophy sets in, for example, if muscles can no longer be used as a consequence of nerve damage and therefore muscle mass decreases.
This therapy includes heat treatments, special massages of the face and special exercises. A skilled therapist will guide the patient through specific movements of the facial muscles. The patient can also perform these exercises at home to improve the healing process.
Which doctors & clinics specialize in facial nerve palsy?
The causes and treatment options for facial nerve palsy are diverse. It is therefore important to clarify the symptoms in detail and carry out an extensive diagnosis.
The doctors and clinics listed here have been carefully reviewed and selected by us for their experience in diagnosing and treating facial nerve palsy.
You can benefit from this experience and schedule an initial consultation with one of our experts fast and easily.
Sources:
Amboss, Nachschlagewerk für Mediziner
„Neurologie“, Werner Hacke, Springer Verlag, 14. Auflage, 2015