What Causes Facial Paralysis?
Facial Paralysis; The facial nerve (facial nerve), which has the longest bony canal among the nerves that move the muscles in the body, is one of the nerves most commonly affected by paralysis. Approximately 90% of these cases occur due to diseases within the ear bone through which the nerve passes. Although the most common cause of facial paralysis is Bell’s palsy, which is generally a self-limiting condition, it should also be kept in mind that pathologies such as infections causing bone destruction or tumors originating from the middle ear may also cause paralysis. Since the treatment of diseases in this region falls within the field of otolaryngology, all patients diagnosed with facial paralysis should undergo an ENT evaluation.
After leaving the brain, some of the nerve fibers reaching the upper half of the face through the facial nerve remain on the same side of the face, while others cross over to the opposite side. However, all nerve fibers controlling the lower half of the face cross over to stimulate the muscles on the opposite side. Therefore, in pathologies occurring on one side of the brain, although the muscles of the lower half of the face on the opposite side are affected, the upper facial region remains unaffected because it also receives stimulation from the healthy brain on the same side. These types of paralysis are called “central facial paralysis“, while paralysis resulting from pathologies in the brainstem and lower regions is referred to as “peripheral facial paralysis.” Although this finding is important in differential diagnosis, it should not be forgotten that preservation of upper facial movement may also occur in certain peripheral facial nerve pathologies.
After leaving the brain, the facial nerve travels together with the hearing and balance nerve and enters the ear bone. In pathologies affecting this region, known as the internal auditory canal, hearing loss and balance complaints may accompany facial paralysis.
As the facial nerve progresses through the canal within the ear bone, it gives off branches that stimulate the lacrimal gland, stimulate the stapedius muscle in the middle ear, provide taste sensation to the anterior two-thirds of the tongue, and activate the submandibular salivary glands. After exiting the ear bone, the nerve extends forward, passes through the parotid salivary gland, and divides into branches that stimulate the facial expression muscles.
In facial paralysis, the presence or absence of tear secretion, taste sensation on the tongue, and stapedius muscle function are helpful findings in determining the location of the disease.
In Which Diseases Is Facial Paralysis Seen?
Although the causes of facial paralysis are highly varied, the most common can be grouped into two categories: acute rapidly developing and chronic slowly progressing.
Acute rapidly developing paralysis:
- Neuritis
- Bell’s palsy
- Herpes Zoster
- Guillain-Barré syndrome
- Autoimmune facial paralysis or Lyme disease
- AIDS
- Kawasaki disease
- Trauma
- Ear bone fractures
- Barotrauma
- Birth trauma
- Middle ear infections
- Acute bacterial infections
- Chronic bacterial infections
- Formation of bone-eroding tissue (Cholesteatoma) in chronic middle ear infection
- Sarcoidosis
- Neurological nervous system diseases
Chronic slowly progressing paralysis:
- Malignant tumors
- Parotid salivary gland tumors
- Metastatic tumors
- Benign tumors (glomus tumor, schwannoma)
- Chronic middle ear infections (Cholesteatoma)
Treatment of Facial Paralysis:
The treatment of facial paralysis varies depending on the underlying cause. The goals of treatment are to restore the normal appearance of the face, achieve facial symmetry during voluntary movement, and preserve emotional expressions as well as the functions of the muscles around the mouth, nose, and eyes.
Bell’s Palsy:
Acute facial paralysis without an obvious cause such as trauma, tumor, or infection is referred to as Bell’s palsy. Although the exact cause is unknown, it is believed to result from a viral infection through an immune-mediated mechanism. Bell’s palsy is a self-limiting condition and is not progressive, usually resolving spontaneously. In 80–90% of patients, the paralysis resolves completely, and this rate increases to 95–100% in patients without complete loss of movement. However, in patients with complete paralysis and more than 90% nerve fiber loss detected in early testing, the complete recovery rate decreases to approximately 50%.
In the treatment of Bell’s palsy, patients presenting within the first four days after the onset of paralysis receive intravenous corticosteroids, provided there is no contraindication, followed by oral corticosteroid therapy with gradual dose reduction every 2–3 days for an average of 15 days. Gastroprotective treatment should also be administered to prevent gastrointestinal side effects of corticosteroids. Since a viral cause is possible, oral antiviral medication is added to the treatment. During the period when facial nerve function is absent, warm compresses, massage, and facial exercises are applied to prevent facial muscle atrophy. Protective eye care is also provided to prevent complications such as keratitis due to dryness.
In cases where corticosteroid use is contraindicated (uncontrolled diabetes, pregnancy, etc.), treatment aimed at increasing capillary circulation may be given. During follow-up, if improvement is observed after three weeks, supportive treatment is continued. Patients without clinical improvement undergo electromyography (EMG). If EMG shows signs of recovery, observation continues. In patients with complete loss of stimulation and no signs of recovery, magnetic resonance imaging (MRI) is performed. If the location of the pathology is identified, surgery is performed using an appropriate surgical technique to decompress the nerve within its canal. The longer the paralysis persists, the poorer the quality of recovery becomes. It is accepted that performing surgical intervention as early as possible is the most important factor in achieving the best possible restoration of facial function. Therefore, early diagnosis and appropriate treatment have a significant impact on recovery in patients with facial paralysis.
Trauma:
Trauma is the second most common cause of facial paralysis. It may result from ear bone fractures, surgical trauma (unavoidable injuries during surgery), or accidental surgical trauma.
Ear Bone Fractures:
Facial paralysis occurring immediately after trauma is considered to indicate nerve transection or injury. In such cases, surgery should be performed as soon as possible, and the nerve should be repaired using the appropriate surgical technique according to the pathology. Paralysis developing some time after trauma may result from swelling or bleeding within the nerve canal. In this case, treatment is similar to that of Bell’s palsy. Surgical decompression is considered in cases that do not respond to treatment.
Acute and Chronic Middle Ear Infections:
In the treatment of facial paralysis occurring during acute middle ear infection, intravenous antibiotics should be initiated, and an incision should be made in the eardrum to drain the accumulated pus from the middle ear. Corticosteroid treatment may also be added.
In paralysis associated with chronic middle ear infection, there is a high likelihood of the presence of a cholesteatoma, a destructive inflammatory mass that enlarges by eroding bone. Paralysis develops due to compression of the nerve by the cholesteatoma or regional inflammation. These cases require emergency surgical intervention.
Herpes Zoster Oticus:
(Ramsay Hunt Syndrome) It is caused by the Varicella Zoster virus. It is usually accompanied by blister-like lesions resembling cold sores on the auricle, scalp, face, or lips. Unlike Bell’s palsy, the symptoms are more severe and generally cause complete nerve damage. It is more common especially in individuals with cellular immune deficiency. The complete recovery rate is low, ranging between 10% and 22%. Treatment should include antiviral medication specific to this virus. The remainder of the treatment protocol is the same as for Bell’s palsy.
Pathologies outside the ear bone: These generally occur due to trauma or tumors originating from the parotid salivary gland. Different surgical methods are used in treatment depending on the underlying cause.
Frequently Asked Questions
What Is Facial Paralysis?
Facial paralysis is a condition in which weakness or loss of movement occurs on one side of the face, or rarely on both sides, as a result of damage to the nerve that controls the facial muscles.
What Causes Facial Paralysis?
Facial paralysis may occur due to various causes such as viral infections, Bell’s palsy, trauma, stroke, tumors, ear infections, and certain neurological diseases.
What Are the Symptoms of Facial Paralysis?
The most common symptoms include drooping on one side of the face, inability to close the eye, drooping at the corner of the mouth, difficulty speaking and eating, changes in the sense of taste, and pain around the ear.
How Is Facial Paralysis Diagnosed?
Diagnosis is made through the patient’s medical history, physical examination, and neurological evaluation. When necessary, additional tests such as imaging methods, blood tests, or electromyography (EMG) may be requested.
How Is Facial Paralysis Treated?
Treatment is planned according to the underlying cause of facial paralysis. Medication, physical therapy, facial exercises, protective eye care, and, in some cases, surgical methods may be preferred.
Is Facial Paralysis Permanent?
No, many cases of facial paralysis can recover completely or to a great extent with appropriate treatment. However, the recovery period and outcomes may vary depending on the underlying cause.
How Long Does It Take to Recover from Facial Paralysis?
The recovery period varies from person to person. While improvement may be seen within a few weeks in mild cases, complete recovery may take several months in some patients.
How Should the Eye Be Protected During Facial Paralysis?
If the eyelid cannot be fully closed, artificial tears, eye ointments, and, when necessary, a protective eye patch may be used. This helps prevent dry eye and corneal damage.
Can Facial Paralysis Recur?
Yes, facial paralysis may rarely recur in some individuals. In recurrent cases, it is important to investigate the underlying causes in detail.
Which Department Should Be Consulted for Facial Paralysis?
If symptoms of facial paralysis occur, an Ear, Nose, and Throat (ENT) specialist or a Neurology specialist should be consulted without delay. Early diagnosis and treatment may increase the chance of recovery.
