What Is Facial Nerve Palsy?

Facial nerve palsy is the diminished function of the facial nerve or one of its branches. Bell’s palsy, which results in the complete inability to move one side of the face, is the most common cause of facial nerve palsy. This condition completely or partially improves within a few months, and it doesn’t cause harm to overall health.

There are other types and causes of facial nerve palsy, and they tend to be longer-lasting and more concerning than Bell’s palsy. This article will discuss the symptoms, causes, diagnosis, and treatment of facial nerve palsy.

Facial Nerve Palsy Symptoms

Facial nerve palsy affects one side of the face. It can affect the whole side or just part of a side of the face. The main symptom is weakness, but sometimes sensory changes, like tingling or loss of sensation, can also occur. 

Symptoms of facial nerve palsy include:

• Droopy eyelid 
• Eyelid that won’t close 
• Droopy cheek 
• Flattening of the nasolabial fold (the crease above the smile)
• Lopsided smile 
• Uneven face

These symptoms can affect the forehead, the lower part of the face, or the upper and lower part of the face. Facial nerve palsy affects only one side of the face.

Associated symptoms can include tingling, numbness, burning, pain, diminished sensation, hearing loss, or dizziness. Facial nerve palsy can cause complications due to the inability to move parts of the face. Complications are more likely if the condition lasts for a long time and if the weakness is severe.

Causes

Facial nerve palsy can be caused by inflammation or damage to the facial nerve. The most common condition that causes facial nerve palsy is Bell’s palsy. It is considered idiopathic (without a known specific cause or trigger) and is believed to result from inflammation.

Other causes can include trauma or an injury to the facial nerve or one of its branches. This may occur due to an accident or as a result of a procedure, such as the removal of a tumor that has grown near the facial nerve.

Ramsay Hunt syndrome is a condition involving facial nerve weakness that can occur as a complication of shingles (a painful rash that can occur years after recovering from a chicken pox infection).

Neuropathy (nerve disease), inflammatory diseases (such as lupus), an infection, or cancer invading the nerve may cause facial nerve palsy as well—although these causes are not common.

Diagnosis

Facial nerve palsy is diagnosed based on a history of symptoms and a physical examination. Weakness of the face caused by a facial nerve problem can affect the forehead, whereas weakness of the face caused by a problem in the brain—like a stroke—will not typically affect the forehead.

A careful neurological examination can help determine whether facial weakness is caused by a condition affecting the nerve or by a condition affecting the brain.

An examination of the mouth, throat, and face can determine if there is swelling or evidence of an infection. Examination of eye movements and vision can help identify whether other cranial nerves besides the facial nerve are involved.

Sometimes tests may be needed to help identify the cause of facial nerve palsy.

These can include:

• Blood tests may identify features of an infection or inflammation.
• Brain imaging studies may identify other potential causes of facial weakness, such as a brain aneurysm (bulge in an artery in the brain) or multiple sclerosis (a condition in which the immune system mistakenly attacks the protective lining of the nerves).
• Electromyography (EMG) or nerve conduction studies (NCV) can examine the function of the muscles and nerves, which may help identify unusual patterns of nerve damage.
• Rarely, a spinal tap (also called a lumbar puncture) is done to look for signs of infection, inflammation, or cancer in the spinal fluid.

Treatment

Sometimes medical or surgical interventions can help alleviate some of the effects and symptoms of facial nerve palsy. Generally, Bell’s palsy improves without treatment, but often, treatment with oral steroids can speed up recovery and reduce long-term effects.

If facial nerve palsy occurs in association with an inflammatory disorder, anti-inflammatory medication may be prescribed. And for treatment of a bacterial infection, antibiotics and drainage of an abscess (walled-off pocket of infection and pus) may be necessary.

Surgery may benefit some people who have facial nerve palsy. Procedures can include nerve transfer, muscle transfer, or repair of the nerve. Chemotherapy is an option for people who have facial nerve palsy due to cancer.

Physical Therapy

For anyone who has facial nerve palsy of any cause, lifestyle modifications and rehabilitation can help with movement and with preventing complications. This can include speech and swallow therapy, as well as facial exercises.

Summary 

Facial nerve palsy is damage or disease of the facial nerve. It causes weakness of movement on one side of the face. Bell’s palsy, a nerve injury, and Ramsay Hunt syndrome are the most common causes. Other less common causes include an infection, inflammation, cancer, and neuropathy.

Differentiating facial nerve palsy from brain disease, such as stroke or multiple sclerosis, is important because the urgency and treatment differ based on the cause of facial weakness.

The treatment of facial nerve palsy often involves anti-inflammatory medication and physical therapy. Other treatments, such as antibiotics, chemotherapy, or surgery, are specific to the cause.

A Word From Verywell

Coping with facial weakness can be stressful. Seek medical attention if you develop this symptom. Facial nerve palsy will usually resolve, but it’s important to maintain preventive strategies to avoid complications—such as eye damage from being unable to close the eyelid.

After you recover from an episode of facial nerve palsy, you can continue to do your muscle exercises until you feel that you have regained adequate control of your facial movements.