Facial paralysis is a disease that affects the facial nerve. It is a medical condition that can occur as a result of sudden nerve damage, facial weakness, Bell’s palsy, etc. Facial paralysis is usually the result of a different medical condition or disease due to which the facial nerve was affected.
What is facial paralysis?
Facial paralysis is the inability to move the facial muscles on one or both sides of the face. Nerve injuries resulting from congenital (existing from birth) disorders, trauma, or conditions such as strokes, brain tumors, or Bell’s palsy can cause facial paralysis. This disease can affect one or both sides of the face, causing loss of features, as well as difficulties in speaking, blinking, swallowing saliva, eating or interacting through natural facial expressions.
When the facial nerve, commonly known as cranial nerve number 7, is damaged, facial paralysis occurs. The facial nerve controls various processes in the face, including stimulation of the muscles that control facial movements, the gland that produces tears, the small muscle in the ear that muffles certain noises, the taste receptor on the tongue, and sensation in a small area of the skin of the ear. Depending on the severity and location of the facial nerve injury, it can affect various elements of the face.
Diseases that cause facial paralysis
Bell’s palsy is a disease that causes momentary paralysis of the facial muscles. It occurs when the seventh cranial nerve becomes inflamed and swollen as a result of a condition such as a viral infection (the nerve that controls the facial muscles). Bell’s palsy causes the face to droop on one side or, in rare cases, on both sides. You may have a crooked smile or a stubborn eyelid. These side effects usually last a few months and go away on their own. Sir Charles Bell, a Scottish surgeon who originally characterized the disease in the 19th century, gave it his name.
This condition has been linked to a higher incidence of other diseases, such as pregnancy and diabetes. Facial paralysis is more common in the third trimester and usually disappears after the baby is born. It can also develop in the postpartum period in some circumstances.
Congenital facial paralysis is one that may be present at birth, and the cause is usually unknown. In the past, when babies were delivered with forceps, it was common for the facial nerve to be damaged. Congenital facial paralysis can be part of a syndrome that affects one or both sides of the face.
Moebius syndrome is a rare form of bilateral facial paralysis that also affects the sixth cranial nerve (abducens nerve), which controls lateral movement of the eyes. Moebius syndrome manifests itself in a variety of ways, making it difficult to identify at birth. In addition, other cranial nerves are often affected, and abnormalities in the limbs, chest muscles, eyelids, ear, and lip malformations are common. Many patients continue to enjoy good health. The exact cause of this syndrome is unknown.
Facial paralysis can be caused by a variety of viruses , such as varicella-zoster, herpes simplex, and Epstein-Barr (EBV). Ramsay-Hunt syndrome is caused by the varicella-zoster virus and is characterized by ear discomfort, regional facial paralysis, and a rash in the ear canal. Hearing loss, severe noise intolerance, and decreased lacrimation are symptoms of Ramsay-Hunt syndrome. Compared with Bell’s palsy, complete recovery is less common, and more patients develop complete sensory loss and synkinesis. Facial paralysis can also be caused by ear infections, infectious mononucleosis, and AIDS.
A stroke is a more dangerous cause of facial paralysis. When the nerves that control the facial muscles are destroyed in the brain after a stroke, facial paralysis occurs. Damage to brain cells is triggered by a lack of oxygen or excess pressure on brain cells caused by hemorrhage, depending on the nature of the stroke. In each situation, brain cells can be annihilated in minutes.
In addition to these diseases, trauma (intra and extracranial), surgery, Lyme disease, etc., can cause facial paralysis.
Symptoms
Sagging skin around the eyebrow, eye, cheek, and mouth are signs of facial nerve palsy. When a muscle loses its ability to move, it completely relaxes, as does the skin over it. Some people may retain some control of their facial muscles or experience muscle spasms or contractions, while others are unable to operate any muscles on the affected side of the face. You can suffer from dry eyes and other eye problems, since the disease prevents the eyelid from closing. Facial nerve paralysis can make it difficult to eat and speak.
You may also notice that, on the affected side, you may have pain around your jaw or in or behind your ear, increased sensitivity to sound, headache, loss of taste, and changes in the number of tears and saliva you produce.
diagnostic tests
Your doctor will visually examine your face to determine the extent of your paralysis. He or she will ask you about the onset of symptoms, how quickly the paralysis has progressed, and whether you have any muscular control over the affected part of your face. The doctor will also ask about any other symptoms you may have, such as hearing loss or tinnitus (persistent ringing in the ears).
The entire facial nerve is examined using an MRI . Your doctor may suggest an MRI that uses gadolinium as a contrast agent or dye. The dye travels to the facial nerve after being injected into the circulation, revealing the foci of inflammation.
The stapedius reflex test is a type of hearing test used by audiologists to determine deficiencies of the seventh cranial nerve. Audiologists specialize in hearing loss, balance problems, and related disorders.
Treatment
Facial paralysis can be intermittent or permanent. The facial plastic surgery team decides the appropriate treatment based on how long the paralysis has lasted, the etiology, and whether the paralysis is complete or incomplete (or partial).
Treatment options are facial palsy surgery, nerve transfers, temporalis tendon transfer, gracilis muscle transfer, crossed facial nerve graft, etc.
References:
Bell’s Palsy (2020). Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/5457-bells-palsy
Facial Paralysis. (2022). Johns Hopkins medicine. https://www.hopkinsmedicine.org/health/conditions-and-diseases/facial-paralysis
Moores, D. (2018). Facial Paralysis. Healthline Media. https://www.healthline.com/health/facial-paralysis
Rubin, M. (2022). Bell’s palsy. MSD Manuals. https://www.msdmanuals.com/en/home/brain,-spinal-spinal-and-nerve-diseases/cranial-pair-disorders/bell-par%C3%A1lysis?query=bell
