By Chinedu Akpa. B. Pharm. Freelance Health Writer, with medical and editorial review by the DLHA Team
Image of a black man with right-sided peripheral facial nerve paralysis showing drooping eyelid, asymmetrical smile, drooping angle of mouth and inability to wrinkle brow. Image credit: JEMS-EMS
Nerve cells in the human brain and spinal cord control all of your movements, including walking, running, talking, clapping, winking, smiling, etc.
A disorder like Bell's palsy (BP) helps us to understand that some of the simplest tasks and gestures like winking, chewing, and smiling can become very difficult.
Bell's palsy represents approximately 80% of all cases of facial paralysis, making it the most common type. According to studies, for every 100,000 individuals screened for Bell’s palsy, 11–40 are affected. It occurs more commonly in people between the ages of 15 and 50. [1]
The left and right sides of the face are equally affected, and the condition affects both males and females equally. [2] There is no segregation in terms of race, ethnic group or age of those that can be affected by BP. [3]
So, what exactly is Bell's palsy and why should you be concerned?
Bell's palsy (otherwise known as peripheral facial paralysis) is a term used to describe the inability to move muscles of one half of your face due to damage to the nerve fibres that supply signals that move the muscles. The damage denies you the ability to wink, blink, smile, or perform other facial movements or expressions. [3]
The movement of facial muscle is controlled by signals delivered by the facial nerve, (also known as the seventh cranial nerve).
The damage to the facial nerve in Bell’s palsy is commonly due to injury (trauma) or inflammation.
The cause of BP has been debated among scientists for a long time, and the general belief is that the cause is unknown. [1] However, suggestions have been made as to the possible causes of this disease.
It is speculated that the Herpes zoster virus (HZV) - the same virus that causes chickenpox in children and Herpes simplex virus-1 (HSV-1) may each be the cause of Bell's palsy. As these germs affect and lie quiet in the human body, it is believed that BP is caused by the reactivation of the germs in the nerve cells that regulate facial movements when the body’s immune system is low. [1]
The speculation has been further supported by studies in which HSV-1 DNA was successfully extracted from the nerve responsible for controlling facial movement in a patient with BP. [1]
To add to the role of HSV-1 and HZV in BP; facial paralysis occurs 100 times more often in people with HSV-1 than others. [4]. This is explained by the body's weakened immune system, which leads to activation of latent (hidden) infections and a rise in the frequency of facial movement paralysis as previously indicated.
Apparently, when HZV or HSV-1 infection is clearly confirmed as a cause of unilateral peripheral facial (Bell’s) palsy through evident rash around the ear or in the mouth, the condition is called Ramsay Hunt syndrome.
There are other infectious agents associated with Bell's palsy besides HSV-1 and HZV. They include:
Non-infectious causes of Bell's palsy are
Certain medical conditions can raise your risk of developing BP. For example, Bell's palsy is three times more common in pregnant women than in non-pregnant ones. An increased risk of contracting the disease is also seen in individuals with hypothyroidism, diabetes, the elderly, and people with compromised immune systems. [1]
Figure 1: Showing soms signs of Bell’s palsy in a black man. Image credit: JEMS-EMS
The signs and symptoms of Bell's Palsy (see figure 1) may overlap with symptoms of other conditions like stroke. For this reason, it is always important to visit your doctor if or when you suffer from any of the following:
When Bell's palsy symptoms are first noticed, stroke is typically the first suspect among many, due to the common occurrence of cardiovascular diseases.
Do Bell's palsy and stroke symptoms resemble each other in any way? Yes indeed, there are some similarities that are noted below.
Despite these similarities, Bell's palsy and stroke are not the same condition. Bell's palsy is brought on by inflammation or injury to the facial nerve, whereas stroke is brought on by blockage of the blood vessels that supply the brain or brainstem.
Your doctor is able to tell the difference between symptoms and signs of facial paralysis due to Bell’s palsy and stroke.
Misdiagnosis rates for BP range from 13 to 20 percent, and this can be explained by the similarities between the symptoms of BP and those of other illnesses. [1] Stroke isn't the only condition that could be misdiagnosed with BP after all, and this is why a proper diagnosis is needed.
Bell's palsy is typically diagnosed by reviewing your medical history, which is usually followed by a comprehensive physical examination by your doctor. Additionally, it has been demonstrated that a history of herpes zoster infection can facilitate diagnosis.
Laboratory and imaging tests are usually recommended mostly in cases of recurrence or when there has not been improvement in treatment after 21 days. [1]
A medical tool used to grade the likelihood of recovery and also determine the degree of paralysis is the modified House-Brackmann scale. The score goes from 1 to 6, where a 6 denotes complete paralysis. Additional tools that help in gathering information for decision making about surgery or treatment of your BP are two procedures known as electromyography (EMG) and nerve conduction studies (NCS). [1] These procedures check the responses of the muscles of your face to electrical stimulation of the facial nerve as well as to active movements (EMG). NCS helps to check the functioning and integrity of the facial nerve
The treatment of BP is based on three approaches as follows:
It is interesting to note that Bell's palsy may resolve on its own without the need for medication or medical attention. [5] For this reason, and depending on how soon after the onset of your symptoms that you visit your doctor, your doctor may decide that no action needs to be taken besides advising such basic support as rest, diet and use of non-steroidal anti-inflammatory drugs like ibuprofen for pain.
If your symptoms show no signs of improvement after 3 to 4 days of watching, your doctor may decide to offer you some medications to treat your BP. The medications may include:
Owing to the lack of clarity surrounding the most effective treatment for Bell's palsy, Adour and colleagues conducted a comprehensive study in 1972 and found that 89% of patients receiving prednisolone, a type of steroid, made a full recovery. Subsequent studies have since confirmed the effectiveness of prednisolone in reducing the symptoms and duration of Bell's palsy symptoms when administered within 72 hours of the onset of symptoms. [5]
Caution must be exercised in the use of steroids if you are pregnant or known to suffer from certain chronic diseases like tuberculosis, active infection, peptic ulcer, diabetes mellitus, renal dysfunction, and sarcoidosis.
Antiviral medications may not be helpful in treating all cases of Bell palsy, according to a number of studies. However, since one of the common causes of Bell's palsy originates from herpes zoster and related viruses, the use of antiviral agents like acyclovir and valacyclovir in such instances is a common clinical practice with questionable benefits as a study conducted on 1,987 patients between 1966 and 2008, found no significant difference in the use of antiviral agents to treat Bell's palsy when compared with those who did not receive the medications. [5]
Can the combination of a steroid and an antiviral agent bring about a better result for BP treatment? Let's find out!
The arguments in favor of and against combining corticosteroids with antiviral medications are inconclusive, as some studies have found benefits while others have found none at all.
An illustration would be a study conducted in Japan with 221 patients. This study revealed a significant difference in the patients who took these medications together. [5] The Japanese results were confirmed by another study conducted by de Almeida and colleagues, which included 2,786 patients pooled from 18 different studies. [5] However, a study by Quant and colleagues with 1,145 patients yielded a different outcome.
The reasons for the variations in results could have been related to interpretation, context, methodology, or sample size.
Additional treatment options for Bell's palsy include acupuncture, botulinum toxin, surgery, and physical therapy.
The eye is not the part of the body that is directly affected by Bell's palsy, so why is an eye drop usually used?
Eye drops or ointment are typically helpful, though they may not be for people with severe or protracted conditions. The reason for using the drops is because you are unable to close your eyes, and this can cause dry eyes and abrasion of the cornea, the area of the eye that lets light into your eye. [1] Hence, lubricating eye drops like hypromellose are used to achieve this.
Acupuncture is a Chinese traditional medicine that has been practiced for thousands of years. The process involves the insertion of fine and clean needles into specific parts of the skin or applying other techniques to the acupuncture to bring about healing. There is currently no sufficient evidence to prove that acupuncture is an effective treatment for BP. [6]
Botulinum toxin is produced from a bacterium called Clostridium botulinum. It works by blocking the activity of a chemical called acetylcholine that makes muscles tighten up. When this happens it causes a reversal in muscle paralysis without long term damage to the muscle or nerves. [7] The botulinum toxin is usually administered as an injection.
In order to determine whether surgery is necessary for your Bell’s palsy, your doctor will assess your general health, the extent of your disability, the presence and condition of your facial nerve, and the underlying cause of the paralysis. You may be eligible for various types of surgery based on the findings that your doctor makes. [8]
For people with temporary or partial paralysis, physical therapy may be appropriate. It may also help those who recently had surgery. There is however no credible evidence that it helps or harms recovery of function in Bell’s palsy.
Physical therapy exercises include neuromuscular retraining, biofeedback, electrical stimulation, and exercise. Recovering BP patients can perform these exercises with a therapist's help.
When your nerves are damaged as a result of BP, some of them attempt to regenerate, albeit abnormally. As a result, a nerve may end up connecting to a part of the body to which it is not supposed to. For instance, the tear duct and facial nerves may be connected, leading to needless tears. [1] Similar to this, certain nerves may try to regenerate by innervating the wrong muscles, which results in disorganized facial movements. [1]
Additionally, some scientists have found that having BP can raise your chance of having a stroke. This opinion was formed following an investigation involving more than 7,000 BP patients, which revealed a stroke risk of 4% compared to 1.6% in the general population. [1]
It would not be socially acceptable for someone to exhibit symptoms such as drooping, drooling, or inability to move the muscles of the face in public. This explains why anxiety and depression are common among BP patients. Additionally, these symptoms may interfere with their sleep pattern.
The stares, unwanted remarks, and inquiries from others may make you as a BP sufferer less likely to interact with others. This has the potential to exacerbate depressive episodes in people with BP. [8]
Yes, you can!
Treatment with oral steroids can increase your chance of recovery by 97%. [3] The extent of nerve damage and the promptness of treatment will determine how well you recover. If medical attention is delayed, some people may have chronic muscle weakness and twitches.
While a recurrence is rare (occurs only in about 7-8% of all cases) you can have episodes of the symptoms years after it first appeared. [9]
Persistent hypertension, diabetes, and pregnancy are some examples of non-infectious causes of Bell’s palsy. Additionally, a history of family recurrence, mutation, and abnormal development of bone tissue in the area of the skull where the facial nerve passes (facial canal) before reaching the muscles of the face, are factors that have been known to cause Bell palsy. [10]
Bell's palsy is not known to be transmitted from person to person. But if the underlying cause of the disease is a germ like herpes simplex or zoster virus then you might be infected with the germ or you infect others. Being infected with herpes virus does not mean you that will come down with Nell's palsy.
Yes, eating and drinking may be a challenge with Bell’s palsy because of the weakness of the muscles of your lips and cheeks and your tendency to dribble saliva from the corner of your mouth. To take care of this, you should use a straw to drink from a cup and try not to eat chewy and dry foods that may prove difficult to swallow because of your condition.
Bell’s palsy (BP) is a condition that causes facial paralysis due to dysfunction of the seventh cranial nerve. It can affect anyone, especially people aged 15-50, with no preference for gender or race. Though the exact cause is unknown, viruses like HSV-1 and HZV are commonly linked, as well as conditions like HIV, diabetes, and pregnancy.
Diagnosis involves medical history and tests, and treatment options range from steroids, antivirals, and eye drops to surgery. BP can resolve on its own, but early treatment improves recovery. Complications include muscle twitching and an increased stroke risk. Recurrence is rare but possible in some cases.
1. Zandian A, Osiro S, Hudson R, Ali IM, Matusz P, Tubbs SR, Loukas M. The neurologist's dilemma: a comprehensive clinical review of Bell's palsy, with emphasis on current management trends. Med Sci Monit. 2014 Jan 20;20:83-90. doi: 10.12659/MSM.889876. PMID: 24441932; PMCID: PMC3907546. Available from here
2. Gilden, DH. Bell's palsy. New England Journal of Medicine, 2004, 351(13), 1323–1331. doi:10.1056/NEJMcp041120. Available from here.
3. Hohman MH, Warner MJ, Varacallo M. Bell Palsy. [Updated 2024 Oct 6]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from here.
4. Kandah O, Liu S, Montesano P. Acute HIV Presenting With Unilateral Facial Nerve Paralysis: A Case Report. Cureus. 2023 Jan 22;15(1):e34062. doi: 10.7759/cureus.34062. PMID: 36824558; PMCID: PMC9943581. Available from here.
5. Medscape.Bell palsy treatment and management. [ internet,n.d]. Cited October 15th, 2024. Available from here.
6. Li P, Qiu T, Qin C. Efficacy of Acupuncture for Bell's Palsy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. PLoS One. 2015 May 14;10(5):e0121880. doi: 10.1371/journal.pone.0121880. PMID: 25974022; PMCID: PMC4431843. Available from here.
7.de Sanctis Pecora C, Shitara D. Botulinum Toxin Type A to Improve Facial Symmetry in Facial Palsy: A Practical Guideline and Clinical Experience. Toxins (Basel). 2021 Feb 18;13(2):159. doi: 10.3390/toxins13020159. PMID: 33670477; PMCID: PMC7923088. Available from here.
8. Pinkiewicz M, Dorobisz K, Zatonski T. A Comprehensive Approach to Facial Reanimation: A Systematic Review. J Clin Med. 2022 May 20;11(10):2890. doi: 10.3390/jcm11102890. Available from here.
9. Swami H, Dutta A, Nambiar S. Recurrent Bell's Palsy. Med J Armed Forces India. 2010 Jan;66(1):95-6. doi: 10.1016/S0377-1237(10)80115-7. Available from here.
Published: October 22, 2024
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