Bell palsy, often known as idiopathic facial paralysis, is the most common cause of unilateral facial paralysis. It is one of the most common neurologic cranial nerve conditions. In most cases, Bell’s palsy resolves gradually over time, and its exact cause is unknown.
Bell palsy is caused by unilateral inflammation of the seventh cranial nerve, which results in weakness or paralysis of the facial muscle on the affected side. The diagnosis is one of exclusion and is most often made on a physical exam. The motor function of the facial nerve controls the upper and lower facial muscles. As a result, the diagnosis of Bell palsy requires special attention to forehead muscle strength. If forehead strength is preserved, a central cause of weakness should be considered.
Controversy surrounds the etiology of Bell palsy. The cause of Bell palsy remains unknown, though the disorder appears to be a polyneuritis with possible viral, inflammatory, autoimmune, and ischemic etiologies
- Herpes simplex virus. The hypothesis that HSV is the etiologic agent in Bell palsy holds that after causing a primary infection on the lips, the virus travels up the axons of the sensory nerves and resides in the geniculate ganglion. At times of stress, the virus reactivates and causes local damage to the myelin.
- Autoimmune reactions. Bell palsy may also be secondary to autoimmune reactions that cause the facial nerve to demyelinate, resulting in unilateral facial paralysis.
- Family history. A family history of Bell palsy has been reported in approximately 4% of cases. Inheritance in such cases may be autosomal dominant with low penetration; however, which predisposing factors are inherited is unclear.
The annual incidence is 15 to 20 per 100,000 with 40,000 new cases each year and the lifetime risk is one in 60. There is an 8 to 12% recurrence rate. Even without treatment, 70% of clients will have a complete resolution. Very few cases are observed during the summer months. Internationally, the highest incidence was found in a study in Seckori, Japan, in 1986, and the lowest incidence was found in Sweden in 1971. Most population studies generally show an annual incidence of 15 to 30 cases per 100,000 population.
Bell’s Palsy Grading System: A Scale of 1 to 6
The grading system developed by House and Brackmann categorizes Bell’s palsy on a scale of I to VI.
- Grade 1: Normal function
- Grade II: Mild dysfunction; slight weakness noted on close inspection, slight synkinesis may be present, normal symmetry and tone are noted at rest, forehead motion is moderate to good, complete eye closure is achieved with minimal effort, and slight mouth asymmetry is noted.
- Grade III: Moderate dysfunction; an obvious, but not disfiguring, difference is noted between two sides; a noticeable, but not severe, synkinesis, contracture, or hemifacial spasm is present; normal symmetry and tone are noted at rest; forehead movement is slight to moderate, complete eye closure is achieved with effort, and a slightly weak mouth movement is noted with maximal effort.
- Grade IV: Moderately severe dysfunction; an obvious weakness and/or disfiguring asymmetry is noted, symmetry and tone are normal at rest, no forehead motion is observed, eye closure is incomplete, and an asymmetrical mouth is noted with maximal effort.
- Grade V: Severe dysfunction; only a barely perceptible motion is noted, asymmetry is noted at rest, no forehead motion is observed, eye closure is incomplete, and mouth movement is only slight.
- Grade VI: Total paralysis; there is gross asymmetry and no movement noted.
The objectives of treatment are the following:
- Maintain the muscle tone of the face.
- Prevent or minimize denervation.
- Administration of corticosteroids
- Facial pain is controlled or minimized.
Bell’s palsy is thought to be caused by a compression of the seventh cranial nerve at the geniculate ganglion. Most cases of compression occur in the narrowest region of the facial canal, known as the labyrinthine segment. Inflammation in this location causes nerve compression and restricted blood flow, resulting in ischemia. The most common sign is unilateral facial weakness, which affects the muscles of the forehead and other facial muscles on one side of the face.
Epidemiology of Bell Palsy
- Bell’s palsy is responsible for 60 to 75% of occurrences of acute unilateral facial paralysis.
- In 63% of cases, the right side of the face is affected
- Bilateral simultaneous Bell’s palsy is uncommon, accounting for just 23% of bilateral facial paralysis instances.
- It is more common in immunocompromised people or preeclamptic women.
- Bell’s palsy affects both sexes equally, but young women between the ages of 10 and 19 are more likely than men in the same age group to be affected.
- It is more frequent in adults, with a somewhat higher prevalence in people over the age of 65.
- Children under the age of 13 have a decreased incidence rate.
- Bell’s palsy is most common in people between the ages of 20 and 40, but it can also affect people in their 70s and 80s.
Signs and Symptoms
Clients present with rapid and progressive symptoms over the course of a day to a week often reaching a peak in severity within 72 hours. The key physical finding is a partial or complete weakness of the forehead.
Common signs and symptoms
- Acute onset of unilateral upper and lower facial paralysis. The inflamed, edematous nerve becomes compressed to the point of damage, or its blood supply is occluded, producing ischemic necrosis of the nerve.
- Posterior auricular pain. The pain frequently occurs simultaneously with the paresis, but pain precedes the paresis by 2 to 3 days in about 25% of clients.
- Decreased tearing. Two-thirds of clients complain about tear flow. This results from the reduced function of the orbicularis oculi in transporting the tears. Fewer tears arrive at the lacrimal sac, and overflow occurs.
- Hyperacusis. One-third of clients may experience hyperacusis in the ear ipsilateral to paralysis, which is secondary to weakness of the stapedius muscle.
- Taste disturbances. 80% of clients show a reduced sense of taste. Clients may fail to note reduced taste, because of normal sensation in the uninvolved side of the tongue.
- Otalgia. This is defined as ear pain.
- Weakness of facial muscles. Weakness will be partial or complete to one-half of the face, resulting in weakness of the eyebrows, forehead, and angle of the mouth.
- Lagophthalmos. The inability to close the eyes completely.
- Tingling or numbness of the cheek/mouth. Many clients report numbness on the side of the paralysis. Some authors believe that this is secondary to the involvement of the trigeminal nerve, whereas others argue that this symptom is probably from a lack of mobility of the facial muscles.
The goal of treatment is to improve facial nerve function and reduce neuronal damage. Treatment of Bell’s palsy should be conservative and guided by the severity and probable prognosis in each particular case. Spontaneous recovery is fairly common for clients diagnosed with Bell palsy.
- Topical ocular therapy. This therapy is useful in most cases with the exception of those in which the condition is severe or prolonged. Topical ocular lubrication with artificial tears during the day and lubricating ophthalmic ointment at night, or occasionally ointment day and night, is sufficient to prevent the complications of corneal exposure.
- Corticosteroids. The American Academy of Neurology (AAN) released guidelines stating that steroids are highly likely to be effective and increase the likelihood of recovery of facial nerve function in new-onset Bell palsy.
- Antiviral agents. Evaluation of the use of antiviral medicines in Bell palsy has shown limited benefit from these drugs, however, given the evidence suggesting that a large percentage of Bell palsy cases may result from a viral infection, the use of antiviral agents may be reasonable in certain situations.
- Facial nerve decompression. Surgery may be considered in clients with complete Bell palsy that has not responded to medical therapy and with greater than 90% axonal degeneration.
- Eyelid implants. Implantable devices have been used to restore dynamic lid closure in cases of severe, symptomatic lagophthalmos. These procedures are best for clients with poor Bell phenomenon and decreased corneal sensation.
- Tarsorrhaphy. Tarsorrhaphy decreases horizontal lid opening by fusing the eyelid margins together, increasing support of the precorneal lake of tears and improving coverage of the eye during sleep.
Assessment and Diagnosis
The diagnosis of Bell palsy must be made on the basis of a thorough history and physical examination, as well as the use of diagnostic testing when necessary. Bell palsy is a diagnosis of exclusion.
Clinical features of the disorder that may help distinguish it from other causes of facial paralysis include the sudden onset of unilateral facial paralysis and the absence of signs and symptoms of CNS, ear, and cerebellopontine angle disease.
- Assess for the absence or asymmetry during wrinkling of the forehead on the affected side when raising the eyebrows.
- Assess if the client can close both eyes tightly with the eyelashes buried between the eyelids.
- Assess for the Bell phenomenon (the examiner is able to force open the eyelids, and the eyes have deviated upward and laterally).
- Observe the blink pattern.
- Note the flattening of the nasolabial fold on one side.
- Assess the strength of the buccinator muscle by asking the client to hold air in the mouth against resistance.
- Observe for asymmetry or weakness on the affected side by asking the client to pucker or purse their lips.
- Assess for an asymmetric grimace.
- Assess the client’s sense of taste, sensation, and hearing. Sweet and salty tastes can be screened with sugar and salt.
- Assess the client’s facial nerve reflexes.
Findings during the physical assessment for a client diagnosed with Bell palsy include the following:
- In Bell palsy. Wrinkling of the forehead on the affected side when raising the eyebrows is either asymmetrical or absent.
- In Bell palsy, when the client attempts to close the eyes, the affected side shows incomplete closure and the eye may remain partly open.
- The client who is attempting to close the eyelids tightly but cannot demonstrate the Bell phenomenon.
- The involved side in Bell’s palsy may slightly lag behind the normal eye, and the client may be unable to close the eye completely.
- Flattening of the nasolabial fold on one side indicates facial weakness.
- Abnormalities in taste can support localization of the problem either proximal or distal to the branch point of fibers mediating taste.
Determining whether facial nerve paralysis is peripheral or central is a key step in the diagnosis. The minimum diagnostic criteria include paralysis or paresis of all muscle groups on one side of the face, sudden onset, and absence of central nervous system disease. No specific diagnostic tests are available for Bell palsy, but other diagnostic tests may be useful for identifying or excluding other disorders.
- CT scan/MRI. Imaging with a CT scan or other methods is indicated if there are other associated physical findings or if the paresis is progressive and unremitting. MRI is useful as a means of excluding other pathologies as the cause of paralysis.
- Nerve conduction testing and EMG. nerve conduction velocities and EMG produce a graphic readout of the electrical currents, displayed by stimulating the facial nerve and recording the excitability of the facial muscles it supplies. These tests may aid in assessing the outcome of a client who has persistent and severe Bell palsy.
- Electroneurography is a physiologic test that uses EMG to objectively measure the difference between potentials generated by the facial musculature on both sides of the face in response to supramaximal electrical stimulation of the facial nerve. Electrodiagnostic testing measures facial nerve degeneration indirectly.
- Brainstem auditory evoked response (BAER). This may be obtained in clients with peripheral facial nerve lesions and other neurologic involvement. This test measures the transmission of the response through the brainstem and is effective in detecting retro cochlear lesions.
- If hearing loss is suspected, audiography and auditory evoked potentials should be pursued once an underlying structural lesion has been excluded. Impedance testing may reveal an absent or diminished stapedial reflex.
- Salivary flow test. The healthcare provider places a small catheter into the paralyzed and normal submandibular glands. The client is then asked to suck on a lemon, and the salivary flow is compared between the two sides. The normal side is the control.
- Schirmer blotting test. This test may be used to assess tearing function. The use of benzene will stimulate the nasolacrimal reflex, and the degree of tearing can be compared between the paralyzed and normal sides.
- Nerve excitability test. This test determines the threshold of the electrical stimulus needed to produce visible muscle twitching.
Thorough history taking and examination, including the ears, nose, throat, and cranial nerves, must be performed. In most cases, the diagnosis of Bell palsy is straightforward as long as the client has undergone a thorough history and physical examination. Failure to recognize structural, infectious, or vascular lesions leading to seventh cranial nerve damage may result in further deterioration of the client’s condition.
Complications of Bell palsy may include:
- Irreversible damage to the facial nerve
- Abnormal regrowth of nerve fibers, resulting in involuntary contraction of certain muscles when trying to move others (synkinesis)
- Partial or complete blindness of the eye that won’t close due to excessive dryness and scratching of the cornea
Nursing management of Bell’s palsy involves a comprehensive and compassionate approach to help clients regain optimal facial muscle function, prevent complications, and address emotional well-being. By implementing appropriate interventions and collaborating with the healthcare team, nurses play an essential role in facilitating the recovery and improved quality of life for clients affected by Bell’s palsy.
The clinical examination should include a complete neurologic and general examination, including otoscopy and attention to the skin and parotid gland. Vesicles or scabbing around the ear should prompt testing for herpes zoster. Careful observation during the interview while the client is talking may reveal subtle signs of weakness and provide additional clues.
- Decreased sense of taste
- Posterior auricular pain
- Tingling/numbness of the cheek/mouth
- Blurred vision
- Flattening of the forehead and nasolabial fold on the affected side
- Distorted face and lateralization to the affected side when asked to smile
- Inability to close eye on the affected side
- Absence of tear reflex
Nursing diagnoses applicable for a client diagnosed with (disease) include:
- Risk for Corneal Injury related to decreased blinking and inability to fully close the affected eye
- Acute Pain related to facial muscle weakness, inflammation, or discomfort
- Impaired Swallowing related to facial muscle weakness affecting oral and pharyngeal control
- Disturbed Body Image related to visible facial paralysis, altered facial symmetry
- Impaired Verbal Communication related to difficulty in articulating words or facial expressions
- Risk for Social Isolation related to decreased self-esteem or anxiety
Nursing Care Planning and Goals
The goals appropriate for the care of a client diagnosed with Bell palsy are:
- The client will optimize their facial muscle function.
- The client will experience reduced or diminished pain.
- The client will demonstrate behaviors appropriate to prevent the development of complications
- The client will improve their eye health.
- The client will prevent anxiety and restore their self-esteem.
- The client will achieve successful self-management.
Nursing Interventions for Bell’s Palsy
- Wearing a protective eye cover at night and during the day protects the damaged eye against unintentional trauma or injury, especially during sleep or daytime activity. It acts as a physical barrier, preventing any unintentional touch that could worsen the illness.
- Apply moisturizing eye drops to the affected eye as directed during the day. Eyelid paralysis can result in decreased tear production and dryness of the eye. Moisturizing eye drops lubricate the eye, reduce dryness, and protect the eye from discomfort or injury caused by insufficient tear production.
- Apply an eye ointment at bedtime to prevent eye injury. The eye is prone to harm during sleep due to its inability to close and protect itself normally. Applying an eye ointment before bedtime helps to keep the eye moisturized and avoids dryness and any damage from developing overnight.
- Educate the patient on how to manually close the paralyzed eyelid before going to bed. Because the eyelid is paralyzed, the patient may need to close it manually to protect the eye while sleeping. This movement ensures that the eye is properly covered and sheltered, avoiding dryness, discomfort, and potential injury
- To reduce evaporation from the eye, instruct the patient to use wraparound sunglasses or goggles during the day. Wearing wraparound sunglasses or goggles adds an extra layer of protection against tear evaporation from the eye. This helps maintain eye moisture and prevents dryness by reducing tear evaporation.
- Massaging the face several times a day is recommended if the sensitivity of the nerve to touch has decreased and the patient can bear touching their face. Keeping muscle tone by using a modest upward motion. Facial massage can assist improve blood circulation, muscular tone, and muscle atrophy. Once the patient’s nerve sensitivity has decreased and can tolerate touch, modest upward massage motions enhance the facial muscles, increasing their strength and function.
- To avoid muscle atrophy, suggest using a mirror to perform facial exercises such as wrinkling the forehead, puffing out the cheeks, and whistling. Facial exercises aid in ensuring the preservation of muscular strength and avoiding the development of muscle atrophy caused by nerve paralysis. Wrinkling the forehead, puffing out the cheeks, and whistling are all activities that target different facial muscles, increasing activation while minimizing muscular wasting.
- Instruct the patient to stay out of the cold and drafts. The lack of moisture and discomfort in the affected eye might be exacerbated by cold temperatures and drafts. The patient reduces the danger of increased evaporation and irritation by minimizing exposure to cold air or drafts, providing better eye comfort.
- Corticosteroid and analgesic therapy should be used. Corticosteroids are frequently administered to minimize inflammation and edema caused by nerve paralysis, therefore promoting nerve healing. Analgesics may be administered to alleviate pain or discomfort caused by the condition, thereby increasing the patient’s overall comfort.
- Prepare the patient for the indicated electrodiagnostic procedures. Electrodiagnostic methods, such as electromyography (EMG), can provide useful information regarding the degree and severity of nerve injury, assisting in diagnosis and therapy planning. Explaining the technique, addressing any worries, and assuring the patient’s comfort and cooperation are all part of the preparation process.
- Make arrangements for physical or occupational therapy as directed. Patients with facial nerve paralysis may benefit from physical or occupational treatment. These treatments aim to improve facial muscular strength, coordination, and overall functioning abilities. By scheduling therapy, the patient can receive targeted interventions that will aid in their rehabilitation and improve their quality of life.
After the implementation of nursing interventions, the nurse evaluates if the desired goals and outcomes were achieved. The nurse needs to ensure that:
- Normal facial muscle function is restored.
- Normal facial sensation is restored.
- Hearing function has improved or is restored.
- Normal eye lubrication has been achieved.
- No preventable complications developed.
Discharge and Home Care Guidelines
For clients discharged to their homes, monitoring should be performed on a continual basis based on the following parameters, which help in the overall management of the disease.
- Clients should be instructed to call at two weeks to report the progress of symptoms and to be evaluated within or at one month, with close attention to facial weakness and eye irritation.
- If symptoms have worsened, have shown no improvement, and new symptoms have appeared, further evaluation is needed.
- Appropriate referral to an ophthalmologist, neurologist otolaryngologist, social worker, or plastic surgeon may be necessary. The psychosocial impact of Bell’s palsy cannot be discounted, as the disfigurement can have negative implications for self-esteem and social relationships.
The focus of documentation on a client diagnosed with (disease) should include the following:
- Individual assessment findings, including the client’s description of the response to pain, specifics of pain inventory, expectations of pain management, and acceptable pain level
- Client’s/caregiver’s understanding of individual risks or safety concerns
- Prior medication use; substance abuse
- Plan of care and who is involved in planning
- Teaching plan
- Individual responses to interventions/teaching and actions performed
- Specific actions and changes that are made
- attainment/progress toward desired outcomes
- Modifications to plan of care
- Cheever, K. H., & Hinkle, J. L. (2018). Brunner & Suddarth’s Textbook of Medical-surgical Nursing. Wolters Kluwer.
- Doenges, M. E., Moorhouse, M. F., & Murr, A. C. (2006). Nurse’s Pocket Guide: Diagnoses, Prioritized Interventions, and Rationales. F.A. Davis.
- Patel, D. K., & Levin, K. H. (2015). Bell palsy: Clinical examination and management. Cleveland Journal of Medicine, 82(7).
- Taylor, D. C., & Benbadis, S. R. (2021, May 4). Bell Palsy: Practice Essentials, Background, Anatomy. Medscape Reference. Retrieved June 20, 2023, from https://emedicine.medscape.com/article/1146903-overview
- Warner, M. J., Hutchison, J., & Varacallo, M. (2022, September 4). Bell Palsy – StatPearls. NCBI. Retrieved June 20, 2023, from https://www.ncbi.nlm.nih.gov/books/NBK482290/
- Warner, M. J., Hutchison, J., Varacallo, M., & Busby, T. H. (2022). Bell Palsy (Nursing) – StatPearls. NCBI. Retrieved June 21, 2023.