The Bell's palsy Is a neurological disorder that affects the facial muscles, causing alterations at the aesthetic, functional and psychosocial levels (Benítez et al., 2016).
This pathology is the most common type of facial paralysis and is also called peripheral facial paralysis (Leon-Arcila et al., 2013).
Bell's palsy is caused by the presence of different damage or injury to the facial nerves (cranial nerve VII) (National Institute of Neurological Disorders and Stroke, 2010).
Although it is an alteration that can occur in any age group, the exact etiological causes are unknown. However, in some cases traumatic or viral causes can be identified (León-Arcila et al., 2013).
Generally, the clinical course of Bell's palsy is temporary. In most cases, signs and symptoms begin to disappear a few weeks later (Mayo Clinic, 2014).
Characteristics of Bell's Palsy
At the beginning of the 19th century, a Scottish surgeon called Charles Bell , Described for the first time an alteration that consisted of a complete facial paralysis consequent to a traumatic event in the area of the stylo-mastoid foramen, where the facial nerve runs (Leon-Arcila et al., 2013).
This medical condition was called Bell's palsy And occurs as a consequence of an irruption of facial nerve function (National Institute of Neurological Disorders and Stroke, 2010).
The facial nerves or the cranial nerve VIII, is a structure that contains the nerve fibers that are in charge of controlling a good part of the functions of the facial area (Devéze et al., 2013).
Specifically, the facial nerve performs various motor functions of the muscles of the facial mime, sensitive in the external auditory canal, gustative in the anterior portion of the tongue and some parasympathetic vegetative functions that control the secretions of the lacrimal glands, nasal, Submandibular and sublingual (Devéze et al., 2013).
The cranial nerve VII is a pairwise structure that runs through a bony canal, in the skull, below the ear area, to the facial muscles (National Institute of Neurological Disorders and Stroke, 2010).
When this nerve structure is damaged, injured, or inflamed, the muscles that control facial expression may weaken or become paralyzed (American Academy of Ophthalmology, 2016).
In Bell's palsy, there is a sudden decrease or absence of mobility of the innervated muscles controlled by the Facial nerve . Thus it is possible to observe in the affected person that half of his face is paralyzed or"fall"and can only smile using one side of his face, close a single eye, etc. (American Academy of Ophthalmology, 2016).
Therefore, affected people often present with various deficiencies of facial muscle functions and facial expression, such as the impossibility of closing the eyes, smiling, frowning, raising eyebrows, speaking and / or eating (Benítez et al. ., 2016).
About us
Bell's palsy is one of the most frequent neurological abnormalities being the main cause of facial paralysis (Leon-Arcila et al., 2013).
Thus, Bell's palsy has been observed to be a neurological disorder that affects approximately 40,000 people each year in the United States (National Institute of Neurological Disorders and Stroke, 2010).
Globally, the incidence of Bell's palsy is estimated at approximately 70 cases per 6,000 inhabitants (Benítez et al., 2016).
This medical condition can occur in men and women and in any age group, however, it is less prevalent in the stages of life before 15 years of age and after 60 years (National Institute of Neurological Disorders and Stroke, 2010 ).
In addition, a number of risk factors have been identified that significantly increase their occurrence, including pregnancy, diabetes , Or some respiratory pathologies (National Institute of Neurological Disorders and Stroke, 2010).
Signs and symptoms
The easy nerves have very diverse and complex functions, due to this the presence of an injury in this structure can generate diverse alterations (National Institute of Neurological Disorders and Stroke, 2010).
Therefore, the signs and symptoms of this pathology may fluctuate depending on the severity and the person affected (National Institute of Neurological Disorders and Stroke, 2010).
The most characteristic symptoms of Bell's palsy usually affect one side of the face, so bilateral cases of facial paralysis rarely occur (American Academy of Ophthalmology, 2016).
The clinical course of Bell's palsy usually occurs suddenly and usually includes some of the following medical conditions (Mayo Clinic, 2014):
- Weakness of facial muscles.
- Facial paralysis.
- Difficulty issuing facial expressions.
- Mandibular pain or in the region posterior to the auditory canopy.
- Increased sensitivity to sound.
- Decreased efficacy of sense of taste.
- Recurrent headache.
- Excessive tearing or dry eyes.
In addition, Bell's palsy is an alteration with an important psychological and functional effect, since it can have a great negative impact on patients and their psychosocial environment (León-Arcila et al., 2013).
Its permanent?
The duration of facial paralysis varies. According to the different classifications of this pathology in the medical literature, we can divide this type of affections into transient and permanent ones (Benítez et al., 2016).
Bell's palsy is one of the types of transient facial paralysis (Benitez et al., 2016). In about 80% of cases, the symptoms resolve in about three months, while many others begin to disappear in just two weeks (Clevelan Clinic, 2016).
Causes
This type of facial paralysis occurs when the nerves of the cranial nerve VII are inflamed, compressed or injured, leading to the development of facial paralysis or weakness (National Institute of Neurological Disorders and Stroke, 2010).
Despite this, the etiological cause of nerve damage in Bell's palsy is unknown (National Institute of Neurological Disorders and Stroke, 2010).
Specifically, more than 80% of cases of Bell's palsy are classified as idiopathic (Leon-Arcila et al., 2013), a term used to designate diseases that spontaneously burst and do not present a clearly defined cause.
Despite this, there is another percentage of cases in which the clinical course of Bell's palsy is associated with the presence of other types of pathological agents, such as herpes simplex virus and varicella zoster (León-Arcila et al. 2013).
In addition, other cases of infectious processes, genetic alterations, hormonal variations or traumatic events have also been identified (León-Arcila et al., 2013).
The etiological causes of facial paralysis are multiple and can be classified into congenital or acquired (Benítez et al., 2016).
Easy congenital-type paralyzes may result from congenital trauma, Möebious's syndrome, or mandibular division, although they may also have no known cause. While acquired type facials usually result from a traumatic event or viral inflammatory process (Benítez et al., 2016).
In addition to the conditions outlined above, there are several cases in which the likelihood of Bell's palsy is greater than that of the general population (Mayo Clinic, 2014):
- Women in gestation period: during the third trimester or in the first postpartum days.
- Have an infection in the upper respiratory tract, such as the flu or the common cold.
- Have diabetes.
- Family history compatible with the presence of recurrent Bell palsy.
Diagnosis
There is no specific laboratory test or test used to confirm the presence or diagnosis of Bell's palsy (National Institute of Neurological Disorders and Stroke, 2010).
Instead, this type of pathology of neurological origin is diagnosed based on the clinical presentation, ie, a detailed physical examination is performed in which it must be observed: inability to perform movements or facial expressions, facial weakness, etc. (National Institute of Neurological Disorders and Stroke, 2010).
It is necessary to exclude other medical causes of facial paralysis such as bills of temporal bones, acoustic neuromas, auditory tumors (Leon-Arcila et al., 2013), strokes and other pathologies or neurological conditions (American Academy of Ophthalmology, 2016).
Therefore, several complementary tests are usually used to confirm the presence of Bel's paralysis (León-Arcila et al., 2013).
Specifically, neurophysiological assessment is one of the most commonly used methods for determining the degree of nerve degeneration and prediction of facial function recovery
The electro neurography is one of them, allows quantitative and objective assessment of the presence of a compromise in the facial nerve and, in addition, allows to establish an approximate recovery prognosis (León-Arcila et al., 2013).
In addition to this, other techniques used in the assessment of Bell's palsy are the Electromyography (EMG), magnetic resonance imaging (MRI), or Computed tomography (TC) (National Institute of Neurological Disorders and Stroke, 2010).
Treatment for Bell's palsy
Once the diagnosis of Bell's palsy is made, it is essential to initiate the treatment immediately so that the recovery is complete and in the shortest possible time (Leon-Arcila et al., 2013).
This type of pathology can affect each person differently, in milder cases it is not necessary to use a specific treatment since the symptoms resolve spontaneously in a short time, however, there are other more serious cases.
Although there is no cure or standard treatment for Bell's palsy, the most important goal is the treatment or elimination of the source of neurological damage (National Institute of Neurological Disorders and Stroke, 2010).
In some cases, medical specialists initiate treatment with Corticosteroids Or antiviral drugs within three to four days after the presentation of facial paralysis (Cleveland Clinic, 2015).
Recent research has shown that steroids and antiviral drugs such as acyclovir are an effective therapeutic option for Bell's palsy (National Institute of Neurological Disorders and Stroke, 2010).
In addition, the anti-inflammatory drug known as Prednisone , Is often used to improve facial function and to limit the possible inflammation of nerve areas (National Institute of Neurological Disorders and Stroke, 2010).
On the other hand, the surgical option based on surgical procedures is only considered as the last option when there is total facial paralysis, with no response to drugs (Cleveland Clinic, 2015).
In addition to these factors, it will also be important to consider possible medical complications arising from facial paralysis, such as transient or permanent hearing impairment and ocular irritation or dryness (Cleveland Clinic, 2015).
Bell's palsy can prevent flickering in many cases, so that the eye can be exposed directly to the outside environment permanently. Thus, it is important to keep the eye hydrated and protected from possible injury. Medical specialists often prescribe the use of artificial tears, gels or ocular patches (National Institute of Neurological Disorders and Stroke, 2010).
On the other hand, the use of physiotherapy to help maintain muscle tone of the facial area is beneficial in many affected. There are facial exercises that can prevent the development of permanent contractures (National Institute of Neurological Disorders and Stroke, 2010).
In addition, massages or the application of moist heat may help reduce localized pain (National Institute of Neurological Disorders and Stroke, 2010).
These and other therapeutic measures used in Bell's palsy should be prescribed and implemented by medical specialists in each area.
References
- AAO. (2016). Diagnosis of Bell's Palsy . Retrieved from the American Academy of Ophthalmology.
- Benitez, S., Danilla, S., Troncoso, E., Moya, A., & Mahn, J. (2016). Comprehensive Management of Facial Paralysis. Rev Med Cin Condes, 27 (1), 22-28.
- Cleveland Clinic. (2016). Bell's Palsy . Obtained from Cleveland Clinic.
- Khan, A. (2015). What Is Bell's Palsy? Retrieved from Healthline.
- Leon-Arcila, M., Benzur-Alalus, D., & Alvarez-Jaramillo, J. (2013). Bell's palsy, report of a case. Rev Esp Cir Maxilofac., 35 (4), 162-166.
- Mayo Clinic. (2014). Bell's palsy . Obtained from Mayo Clinic.
- NIH. (2010). Bell's palsy . Retrieved from the National Institute of Neurological Disorders and Stroke.