What are the Different Causes of Facial Paralysis?
Facial paralysis is characterized by the loss of facial movement due to nerve damage. It takes place when an individual is unable to move some or all muscles on one or both sides of the face. As a result, the person’s facial muscles can weaken or appear droopy. This condition can occur suddenly or happen gradually and slowly for months, while the actual paralysis might persist for a short or long time.
Facial paralysis yields various signs and symptoms and can be corrected through facial paralysis surgery. These symptoms may include uneven or asymmetrical facial structures and loose or sagging lower eyelids. It can cause a lack of one’s ability to raise their eyebrows or close their eyelids. The condition can also leave the affected individual unable to raise, lower, or pucker their lips.
The following medical conditions and circumstances can cause facial paralysis:
Congenital Facial Palsy
Congenital facial palsy primarily affects newborn children. This rare form of facial palsy occasionally occurs when the facial nerves or muscles of the baby fail to properly develop while they are inside their mother’s womb. There are also instances in which rare developmental disorders or conditions cause congenital facial palsy. Facial nerve trauma during delivery can also induce this particular condition.
Furthermore, it is quite usual for a child born with congenital facial paralysis to have other disorders such as microtia, cleft palate, deformed extremities, and different types of muscle paralysis. The condition can also affect progress regarding speech development and emotional expression if it is left untreated or unresolved later in life.
Bell’s palsy is a condition that induces inflammation of the facial nerve, often causing the muscles on the affected side of the face to droop. It can also induce symptoms such as drooling, facial weakness, and headaches. While is no specific cause for this type of facial palsy, it is understood that a particular kind of facial nerve trauma to the seventh cranial nerve can cause it. Viral facial nerve infections can also be associated with Bell’s palsy.
The condition can happen to anyone. It usually occurs in individuals who have diabetes or those who are recuperating from viral infections. The symptoms of Bell’s palsy are generally temporary, which is why most individuals recover from the condition entirely within six months.
Moebius syndrome is classified as a rare form of bilateral facial paralysis. It mostly affects the muscles that control one’s facial expressions and eye movement. The exact cause of the condition is currently unspecified. Moebius syndrome has different symptoms which may include:
- Facial muscle weaknesses or paralysis
- Feeding, swallowing or choking issues
- Crossed eyes
- Eye sensitivity
- Excessive drooling
- Absence of facial expression
- Hearing issues
- Dental abnormalities
- Bone deformities in the hands and feet
- Speech problems
Children with this particular condition often experience slow motor skill development. Moebius syndrome can also affect other cranial nerves and chest muscles. It can also make eyelid, ear, and lip abnormalities visible.
A stroke is considered a more severe cause of facial paralysis. In this case, facial paralysis occurs when the nerves that control the facial muscles suffer damage in the brain. Loss of oxygen or excessive brain cell pressure due to bleeding can lead to brain cell damage. These circumstances depend on the type of stroke that the affected person has.
Facial paralysis from a stroke can yield some of the following symptoms:
- The weight of the cheeks can pull the lower eyelid down due to lack of cheek muscle tone and strength
- The face’s tendency to droop, yet maintain a spontaneous or involuntary smile
- Drooling due to the weakness of the corners of the mouth
- Possible problems in understanding another person’s remarks
- Potential issues in finding the proper words to say
- Incoherent speech due to the weakness of the muscles responsible for speech
- Difficulty in swallowing
Surgery or Medical Procedures
Medical intervention can accidentally cause facial paralysis. Sometimes, it can also be an integral part of a procedure that requires facial nerve removal. The following can cause facial paralysis:
- Cosmetic procedures
- Dental procedures
- Mastoid or parotid surgery
- Facial nerve blocks
- Skull base surgery
Most cases of post-procedural facial paralysis are not permanent. Temporary paralysis or neuropraxia is generally caused by procedures performed in the affected nerve area. Patients can see a full recovery from this condition throughout a few months.
Facial paralysis due to trauma can occur in any of the following locations:
- Intracranial trauma
- Extracranial or facial trauma
In intracranial trauma, facial paralysis can be caused by any type of trauma that is powerful enough to induce a temporal bone fracture. The condition is generally seen after motor vehicle accidents or blast injuries and occur more in adults.
On the other hand, extracranial trauma is a facial injury from a knife cut or projectile. Dental procedures or nerve blocks can also cause it but are somewhat rare occurrences.
Tumors can also cause facial paralysis. They can bring about a wide range of symptoms, from an acute paralysis that does not show any improvement over several months to a gradually developing paralysis. Synkinesis or unusual facial twitching or motion commonly occurs with the latter.
There are also cases in which actual tumor removal can result in facial paralysis. Temporary or permanent paralysis can occur following the procedure, but will only happen if the tumor is extremely near or if it encloses the facial nerve. The condition can also occur in other instances wherein surgeons have to alter the nerve for clear tumor removal, especially if it involves the extraction of cancerous tumors.
A number of viruses can also cause facial paralysis. These viruses can include varicella-zoster, herpes simplex, and the Epstein-Barr virus. Varicella-zoster brings about Ramsay-Hunt syndrome, while herpes simplex causes herpes that can occur on different parts of the body. On the other hand, the Epstein-Barr virus induces mononucleosis or the “kissing disease,” which can cause facial paralysis.
Ramsay-Hunt syndrome primarily affects the facial nerve and generally causes peripheral facial paralysis, as well as ear pain and a rash in the ear canal. Hearing loss, noise sensitivity, and minimized tearing are also typical symptoms of this disease.
Lyme disease, a disease that can be acquired from tick bites, is another well-known contagious cause for facial paralysis. Statistics for this particular infection show that facial paralysis develops in around 11% of affected patients, with 30% acquiring the condition on both sides of the face.
Lastly, autoimmune diseases such as multiple sclerosis and Guillain-Barré syndrome can also cause facial paralysis. Individuals with multiple sclerosis can experience facial paralysis at the onset or throughout the disorder. Moreover, Guillain-Barré syndrome has bilateral facial nerve palsy as its most frequent cranial nerve involvement pattern.