An infant with a left facial nerve palsy

An infant with a left facial nerve palsy

There are numerous medical conditions that are seemingly designed to allow proponents of “irregular medicine” to proclaim their treatments to be effective. These conditions tend to be chronic and subjective in nature, or to have waxing and waning courses such that a parent or patient might easily be fooled into assigning a causal relationship between a bogus intervention and a clinical improvement. Brief, self-limited maladies are also quite convenient for people with nothing to offer but false information and false hope. After a recent encounter with a patient, I’ve added a new one to the list: idiopathic facial nerve palsy.

What is idiopathic facial nerve palsy?

Although not the first to do so, facial nerve dysfunction resulting in the sudden and unexplained weakness of all muscles on one side of the face was most famously described by Scottish neurophysiologist Sir Charles Bell in 1830. Hence it is commonly, if not always accurately, referred to as “Bell’s palsy.” Since then our understanding of the condition has progressed considerably, thanks to scientific investigation and improved diagnostic testing. In particular, we have learned that many cases are the result of infection, with ear infections, various human herpes viruses, and the spirochete responsible for Lyme disease being the most common culprits in children.

There are many other potential causes of facial nerve palsy in addition to infections, however. These include birth injury, congenital syndromes, cancer, metabolic and autoimmune diseases, and toxic exposures to name just a few. Bell’s palsy, which represents about half of all cases of facial nerve palsy in children, is the diagnosis given when symptoms appear to be idiopathic, meaning that they occur spontaneously and without an obvious cause. In reality, however, many of these cases are actually caused by viral infections or Lyme if the patient lives in an area where it is endemic.

Overall about 20-30 people out of every 100,000 are diagnosed with Bell’s palsy each year, with a predominance in the adult population. It is fairly uncommon in very young children and there is no particular increased risk based on race, gender, or location. It is not a reportable condition, so exact estimates are hard to determine, but roughly 40,000 people are believed to be diagnosed each year and you have about a 1 in 65 chance over your lifetime.

The key in sorting out these apparently idiopathic acute cases from those that may represent a more concerning underlying condition, like cancer or an aneurysm, is appropriate evaluation by a trained medical professional and judicious use of imaging and laboratory testing. It is not uncommon for pediatric neurologists to become involved, particularly in cases that are severe or persistent. Overall in children, the most common causes of facial nerve palsy are ear infections, Lyme disease (most common in endemic areas), idiopathic (Bell’s palsy), varicella (chicken pox), and herpes zoster (shingles).

What are the signs and symptoms of idiopathic facial nerve palsy?

In most cases of idiopathic facial nerve palsy, weakness of the facial muscles comes on suddenly. Patients or parents will notice decreased movement of the forehead, manifesting as difficulty raising the eyebrow as well as weakness in, if not complete inability to close the affected eyelid. One obvious sign is the disappearance of the nasolabial fold that runs between the cheek and the upper lip. The corner of the patient’s mouth typically droops at rest, and sufferers will have trouble smiling.

Because of the facial nerve’s complex anatomy and function, some patients will experience associated symptoms not related to muscular function. This can include a decreased ability to make tears on the involved side, loss of taste on the anterior two-thirds of the tongue, and increased sensitivity to sound. There is a very crude joke that I learned in medical school regarding one of these, but I won’t repeat it here. Those curious enough can practice their google-fu skills to find it.

An important aspect of the neurological examination of patients presenting with facial nerve palsy is careful attention to the muscles of the forehead. As previously mentioned, with idiopathic facial nerve palsy these muscles should be involved. But what if they aren’t?

We have two facial nerves exiting the brainstem, one for each half of the face, which travel through the skull to the various muscles of the face. The origins of most of each facial nerve’s motor functions lie in the cerebral cortex of the contralateral (opposite side) brain hemisphere. If injury occurs in these “upper motor” neurons, such as from a stroke, a patient will have facial paralysis on the opposite half of the face.

But, because the division of the facial motor nucleus responsible for the forehead actually receives some input from the ipsilateral (same side) hemisphere as well, those muscles are generally spared in the case of a stroke or other problem in the brain itself. Problems with the facial nerve distal to where these motor fibers combine, such as the classic idiopathic facial palsy, will result in total facial involvement. This is known as a peripheral palsy. If the forehead isn’t involved, we worry about something more sinister.

Along these same lines, activation of the facial nerve occurs both intentionally and automatically, such as during a spontaneous display of what you humans call laughter. The peripheral facial nerve and the muscles innervated by its branches don’t know the difference between the two. If the problem occurs after the nerve emerges from the brainstem, nothing works.

But different areas of the brain are involved with these two aspects of facial movement. An injury in one will still allow the other to function. So if you can’t smile on command but watching Dane Cook elicits spontaneous laughter, you need neuroimaging and a better sense of humor.

How is idiopathic facial nerve palsy diagnosed and treated?

Idiopathic facial nerve palsy is a diagnosis of exclusion, requiring a thoughtful history and a thorough physical exam. We need to be even more careful in children because idiopathic palsy is less likely to occur compared to the adult population. All the muscles of the face must be involved to some degree and the onset must be fairly sudden. Weakness/paralysis should not continue to worsen after three weeks and recovery should begin no later than six months after the first sign of weakness.

Again, other causes must be ruled out to the best of our ability. This often includes laboratory testing for Lyme disease in children who may have come into contact with ticks capable of spreading the disease. Although many if not most patients don’t require additional studies, some may undergo electrodiagnostic studies, MRI or CT scanning, or lumbar puncture to obtain cerebrospinal fluid, depending on the specifics of their presentation.

As with most conditions, treatment of facial nerve palsy in children is determined by the specific cause and the severity of the presentation. If there is a specific underlying etiology discovered, such as Lyme disease or a bacterial infection of the middle ear or surrounding bone, it should be treated. Congenital or severe acquired cases that result in permanent loss of movement may benefit from nerve grafting and/or muscle transplantation.

If no cause is discovered, and the diagnosis is idiopathic facial nerve palsy, the gold standard of therapy in adults is an oral steroid as early as possible in the course, and some experts recommend the addition of an antiviral medication that targets herpes simplex virus. The evidence of benefit from this is extremely meager, however. Physical therapy can also be helpful in some cases, serving to preserve function and avoid contracture of the involved muscles.

There is little evidence available to guide treatment in children with idiopathic facial nerve palsy. Based on adult data and expert consensus, steroids are commonly initiated when other causes, particularly leukemia, have been ruled out. In Lyme endemic regions, many children are empirically treated while studies are pending but no consensus has yet been reached on this approach. Antivirals, as with adults, aren’t well supported and are generally reserved for empiric treatment of the most severe cases or when the cause can be clearly attributed to shingles.

In addition to the cosmetic difficulties, one of the more distressing aspects of this condition is drying out of the affected eye and the possible development of corneal abrasions because of an inability to blink or close the eye. Artificial tears are generally prescribed and overnight use of a longer lasting lubricating ointment as well as patching are standard. Sometimes surgical intervention or the placement of a weight into the upper eyelid is necessary to avoid discomfort and injury.

What is the prognosis of idiopathic facial nerve palsy?

The overall prognosis for facial nerve palsy is challenging because such a variety of potential causes exist. Some, such as congenital cases associated with genetic syndromes, are very unlikely to resolve. In these cases, the facial nerve may not have even formed. Traumatic cases, such as after a forceps delivery, almost always demonstrate recovery because the nerve is simply swollen. With idiopathic facial nerve palsy, the prognosis is generally excellent, particularly if it never progresses to complete paralysis and recovery begins within three weeks of onset.

Close to 90% of patients with idiopathic facial nerve palsy will begin to experience recovery within three weeks even without treatment, with many seeing return of function within ten days. The earlier that recovery begins, the more likely it is to be complete. Nearly all patients who have early recovery will have no residual weakness. And most patients with late recovery will at least have moderate improvement. Cases that don’t demonstrate at least partial recovery by a few months were likely misdiagnosed.

Some “alternative” approaches to idiopathic facial nerve palsy

So now that you know the science-based medical understanding of idiopathic facial nerve palsy, it should be easy to see why so many practitioners of quackery CAM integrative medicine quackery claim treatment success, and why their patients might believe that an ineffective remedy worked. If diagnosed correctly, it is a largely self-limited condition and recovery begins fairly soon after onset in most cases. Of course the key is the “if diagnosed correctly” part. There are serious conditions that can present with facial palsy that may require specific treatment to prevent worsening. Imagine a child with leukemic infiltrate of the facial nerve or a brain tumor undergoing months of acupuncture before seeing a real doctor.

A quick online search reveals all the usual suspects. I’m not going to provide an exhaustive debunking of every implausible therapy, however. Maybe another time. Consider this more of a shallow yet fun dive into nonsense that might serve as inspiration for your own investigations, a frustrated laugh, or a cathartic primal scream.

Chiropractic

There is no shortage of chiropractic websites claiming success in treating this condition and making the expected claims about “removing nerve interference” we’ve all come to know and love. But the anatomical assumptions are a bit of a stretch. Each facial nerve leaves the brainstem and exits via a hole in the skull near the ear. It isn’t a spinal nerve and it would be very unlikely that a chiropractic subluxation of the upper vertebrae, if they even existed, would somehow interfere with it.

But they do love their case reports. There are two commonly used as justification for chiropractic care, both of which require a poor understanding of the natural course of the diagnosis to be taken seriously. In the first, a patient reported 70-80% improvement after a chiropractic adjustment and application of low level laser therapy at only 14 days after onset of weakness. Many patients see improvement this quickly even without treatment, plus he had been seen by his primary care doctor first and put on oral steroids. Must have been the chiropractic though. The second report, which sadly doesn’t involve any lasers, documents a patient that recovered steadily with chiropractic manipulation of multiple spinal segments and her skull…over a six month period.

TCM and acupuncture

Not to be outdone, proponents of Traditional Chinese Medicine and acupuncture claim to able to improve symptoms and reduce time to recovery without even accessing the spine. In addition to numerous herbs, vitamins, and a full body massage, they include the following helpful information on the etiology of idiopathic facial nerve palsy:

In traditional Chinese medicine (TCM), the diagnosis for Bell’s Palsy is termed “External Wind-Cold attacking the channels of the face”. According to TCM principles, one of the main implications of this condition is an underlying qi (a person’s inherent energy) deficiency. In China, acupuncture has been used for thousands of years to assist in Bell’s Palsy recovery, and the initial treatment goal according to TCM would be to expel Wind and resolve Damp, as well as to invigorate qi and promote blood circulation to the face. Consistent acupuncture treatments (usually recommended once or twice per week), can help soothe a patient, expedite the paralysis from dissipating, and enhance nerve function.

Of course, readers of Science-Based Medicine know that claims of ancient acupuncture are largely fictional. Modern acupuncture bears little resemblance to what was being done a hundred years ago let alone thousands. It was more akin to astrology-based bloodletting with large spikes than the placement of stainless steel filiform needles gently into the skin while relaxing music plays.

Here is a video of an “acupuncture” treatment involving running an electrical current into the muscles of a patient’s face. Electrical stimulation as a form of physical therapy is a treatment approach that has been tested and shown to not speed or induce recovery. Acupuncturists are simply taking advantage of the post hoc ergo propter hoc fallacy when they claim electroacupuncture, or any other flavor of acupuncture, helps. Here is non-electric acupuncture being used to treat facial palsy. Here is another example, which you know is fake because they are wearing sterile gloves.

This video is actually a very interesting look into the thought process of an average person when faced with something like facial nerve palsy. You’ll notice her demonstrating many of the biases and logical fallacies we discuss on Science-Based Medicine. In the final video documenting the one month course of her weakness, she credits acupuncture as the most helpful intervention, not the steroids, time, or any of the many different interventions she tried, but she admits that she didn’t get needled until the tenth day.

Apparently acupuncture “works” better if you wiggle the needle. In a study that did not include sham acupuncture or a regular care group, patients whose needles were wiggled demonstrated statistically significant improvement in subjective outcomes compared to patients whose needles did not go wee wee wee all the way home. The only objective end point assessed revealed a tiny improvement that is likely clinically meaningless and probably represents noise in the data. My conclusion is that the patients having their needles wiggled knew they were getting “special” acupuncture.

For something a bit more academic, check out these guidelines for a prime example of the failure of EBM when it comes to alternative medicine. Notice all the “Grade A” recommendations. Garbage in, garbage out.

Homeopathy and more!

The University of Michigan Health System, one of many examples of academic medical centers choosing marketing over patient care, provides patients with this handy discussion of the use of homeopathy for Bell’s palsy.

Have you ever wondered which crystal is good for someone with facial nerve palsy? Well wonder no more! It’s obviously Lavender Jade, but be sure it has been freshly cleansed before each application.

If crystals aren’t your thing, practitioners of Face Reflexology claim to be able to reattach severed facial nerves years after the injury.

While perusing the internet looking into alternative remedies for idiopathic facial nerve palsy, I discovered Mudra therapy. This is an alternative practice that involves holding the fingers and hands in specific positions in order to “restore a state of balance in the body and raise the level of the performer’s resistance.” The fingers and thumb represent the “panchamahabhootas” that make up the entire universe: sky, air, fire, water, and earth. According to believers, holding specific finger positions in place can cure a variety of illnesses. Even facial palsy.

Here is a video of a hypnosis session on a patient with facial palsy. It does not appear to have helped despite the claim of amazing results.

Conclusion: Facial nerve palsy doesn’t need quackery

Idiopathic facial nerve palsy may not tend to be a life-threatening or even a serious medical condition in most cases, but it can be extremely distressing to patients and potentially very uncomfortable if appropriate care is not provided. Although there are no medical therapies that have been shown to significantly hasten recovery, it is important for the correct diagnosis to be made, particularly in children who are more likely than adults to have a more concerning etiology of their facial weakness. Rather than one of the many implausible and unproven alternatives, your best bet is science-based care from an appropriately trained medical professional.

 

 

Posted by Clay Jones

Clay Jones, M.D. is a pediatrician practicing at Newton-Wellesley Hospital in Newton, MA, and a regular contributor to the Science-Based Medicine blog. He primarily cares for healthy newborns and hospitalized children, and devotes his full time to educating pediatric residents and medical students. Dr. Jones first became aware of and interested in the incursion of pseudoscience into his chosen profession while completing his pediatric residency at Vanderbilt Children’s Hospital a decade ago. He has since focused his efforts on teaching the application of critical thinking and scientific skepticism to the practice of pediatric medicine. Dr. Jones has no conflicts of interest to disclose and no ties to the pharmaceutical industry. He can be found on Twitter as @skepticpedi and is the co-host of The Prism Podcast with fellow SBM contributor Grant Ritchey.

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