It's not uncommon for emergency clinicians to encounter patients with acute onset of facial nerve palsy. Patients often believe it is a stroke, but it's not if it's a peripheral facial palsy. Many cases of seventh cranial nerve dysfunction are idiopathic, termed Bell's palsy, but some identifiable causes are associated with this abnormality.
It is now thought that most cases of Bell's palsy (formerly idiopathic palsy) are actually a reactivation of herpes simplex, although this cannot be clinically verified. Many patients will recover some function, about 85 percent, and about 70 percent will achieve complete recovery, but it may take months. The main task in the ED is to determine whether the patient has a peripheral or central cause for the facial palsy, with empiric treatments based on the available evidence.
Managing Peripheral Facial Palsy
Garro A, Nigrovic LE
Ann Emerg Med
This interesting article reviews peripheral facial palsy, focusing on potential causes and various treatments. The key to determining whether symptoms are from central or peripheral dysfunction is to evaluate the motor function of the forehead; its musculature receives innervation from both sides of the motor cortex, so a central cause spares paralysis of the forehead because of cross connections. Patients with peripheral facial palsy will have involvement of the forehead and lower face.
The clinician should assess the patient's ability to wrinkle his forehead, smile, and close his eye. The affected side is compared with the normal side, which magnifies the involvement of the forehead musculature. Some patients will be unable to shut an eye completely with maximal effort, and have disfiguring asymmetry of the face at rest. The palsy is considered severe if both conditions are present, an indication for corticosteroids and antiviral treatment.
Identifiable Causes of Peripheral Facial Nerve Palsy: A few unusual causes of peripheral facial palsy can often be diagnosed from the history and physical exam. Some causes are facial nerve trauma, neoplasms, sarcoidosis, a varicella zoster infection of the geniculate ganglion (Ramsay Hunt syndrome), and otitis media in children. Ramsay Hunt syndrome will present with a facial nerve palsy with associated same-sided ear pain and skin vesicles. An acoustic neuroma can cause facial palsy, but the patient usually also reports hearing loss, tinnitus, and unsteady gait.
The first manifestation of early disseminated Lyme disease may be a peripheral facial palsy, and those patients should have a Lyme disease blood test. Up to 25 percent of peripheral facial palsy can be caused by Lyme disease in endemic areas, and bilateral involvement (seen in about 50%) is a tipoff for Lyme. Occasionally an erythema migrans skin lesion can be found or a tick-bite history can be elicited, both indicative of Lyme disease. A first-stage Lyme test is often available in the ED, but the palsy can occasionally occur before blood tests are diagnostic, so physicians may often make empiric treatment decisions based on the best available evidence. Lyme disease should be suspected in those who have associated heart block, arthritis, vertigo, or hearing loss.
Diagnosis: The diagnosis of idiopathic palsy, termed Bell's palsy, can be made without blood tests or neuroimaging in the ED. A two-tier blood test can be done if Lyme disease is suspected. The first tier is an enzyme-linked immunoassay (ELISA) that can be done in many hospitals. The patient requires a confirmatory immunoblot test if this test is positive or equivocal. This test must be sent out, and is routinely performed automatically with the enzyme link immunoassay. Unfortunately, facial nerve palsy from Lyme disease can occasionally occur before serologic tests are positive, so repeat testing in a week or two to document seroconversion is suggested.
Treatment: There is no magic or rapidly effective treatment for this condition. Therapy can be initiated in the ED, but patients require follow-up because the palsy can slowly progress, become worse, and have prolonged healing times. The onset of facial palsy can occur over a few hours, but it may take months for patients to recover. The final prognosis seems to be related to the severity of the lesion, and those with moderate to severe symptoms often have an incomplete recovery. These authors suggest that patients with peripheral facial palsy who present during endemic seasons where the incidence of Lyme disease is high be treated with antibiotics while awaiting serologic tests. First-line treatment for Lyme is doxycycline; it has high efficacy and excellent central nervous system penetration. Most studies suggest 100 mg BID for 14-21 days. These authors believe that doxycycline can be used in children under age 8 because short-term use has minimal risk. Patients with doxycycline intolerance can be given amoxicillin (50 mg/kg, maximum 500 mg) TID for 14-21 days.
About 75 percent of patients with Lyme disease facial palsy will have clinical evidence of meningitis, specifically CFS pleocytosis. It's unclear who should actually receive a lumbar puncture in the presence of straightforward facial palsy from Lyme disease. Most authorities agree that Lyme disease can be treated with doxycycline, including Lyme disease meningitis. These authors do not recommend a routine spinal puncture for patients with suspected Lyme disease facial palsy unless there is concern for bacterial meningitis. They suggest that patients with suspected Lyme facial palsy be treated with doxycycline regardless of their age or the presence of associated headache.
Corticosteroids initiated within three days of facial palsy onset increase the likelihood of recovery, shorten the time of recovery, and reduce involuntary movements. The benefit is not spectacular. Eight patients with severe palsy and 50 with mild to moderate facial palsy needed to be treated with steroids for each additional patient obtaining full clinical recovery. Steroids can reduce the severity of residual facial palsy in those who do not completely recover. It is suggested that corticosteroids be initiated within three days of onset. Steroid regimens vary, but a standard methylprednisolone dose pack or prednisone/prednisolone 60-80 mg/day for 10 days is recommended for adults. These authors recommend that corticosteroids should not be used for patients with a strong suspicion of Lyme disease. Minimal data suggest that corticosteroids are of no value and may be harmful in Lyme disease.
Herpes simplex infections cannot be distinguished from other causes of peripheral facial palsy by clinical presentation, and antiviral therapy is often used to treat this condition. Recommended are valacyclovir 1 g TID or famciclovir 750 mg/day for seven days. Antivirals alone have not been demonstrated to be helpful in adults, but the addition of steroids can be beneficial. Recent evidence has found that antivirals should be prescribed in addition to corticosteroids for patients with the severe form of Bell's palsy. These authors recommend antivirals for all patients with severe facial palsy, with their drug of choice being valacyclovir.
Peripheral facial palsy impairs the patient's normal ability to blink, so the cornea can become dry. Artificial tears are advised every hour while the patient is awake to prevent dryness. Ointment lubrication can be used at night.
These authors conclude that patients with the acute onset of peripheral facial palsy should be initially treated in the ED to improve long-term recovery. Empiric antibiotics while awaiting test results are suggested for those at high risk for Lyme disease. All other patients should be treated with corticosteroids. Patients with severe facial palsy should be treated with combined antivirals and corticosteroids.
Comment: Recommendations for treating peripheral facial palsy vary somewhat among authors. Unfortunately, no treatment is dramatically effective and only minimally helpful at best. It appears more commonly in diabetics during the third trimester of pregnancy, and in the first post-partum week, but race, geography, and gender have no effect on incidence. Idiopathic facial nerve palsy, termed Bell's palsy, represents about half of all patients with facial nerve palsy. A herpes simplex-mediated viral inflammatory mechanism is thought to be involved in a number of cases previously considered to be idiopathic. Herpes simplex virus activation has become widely accepted as a likely cause of Bell's palsy in most patients, although the evidence is not entirely conclusive. A number of other viruses have been implicated.
Bell's palsy typically presents with rapid onset over a few hours and consists of unilateral facial paralysis. Bilateral facial involvement is common in Lyme disease. Findings besides forehead wrinkling and inability to close the eye fully include eyebrow sagging, diminution of the nasolabial fold, and drooping of the corner of the mouth. Some patients have decreased tearing, hyperacusis, or loss of sensation to the anterior two-thirds of the tongue. Onset is acute, but many patients may not reach maximal weakness and paralysis for a few weeks.
The diagnosis is usually made by assessing the musculature of the face, but one should also look at the external ear for vesicles or herpes zoster scabbing. If the musculature of the forehead is intact, look further for a possible central etiology. Electrodiagnostic studies or CNS imaging may be performed, but antivirals and corticosteroids are prescribed in the ED for clear peripheral facial palsy where Lyme disease has been ruled out. Follow-up is important.
The use of glucocorticoids to enhance viral therapy is interesting. The suspicion of Bell's palsy being caused by the herpes simplex virus probably warrants antiviral therapy. There appears to be no benefit of antiviral therapy alone in patients with idiopathic facial palsy. There is a possibility, though it is not proven, that adding antivirals to glucocorticoids is beneficial, particularly in those with severe facial palsy. Most authors suggest a combination therapy of prednisolone and valacyclovir for one week for patients with severe facial palsy. It is unclear whether both are routinely suggested in patients with mild to moderate facial palsy.
Doxycycline does not appear to have a major impact on the outcome of facial palsy, but treatment is recommended for other complications of Lyme disease. Most patients with Lyme facial palsy recover fully within a few weeks. For those with mild and moderate symptoms, a 14-day course is probably adequate, but for those with more severe involvement, three to four weeks of therapy is suggested.
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Peripheral Facial Palsy
- Weakness of upper (forehead) and lower face
- Inability to close an eye fully
- Loss of the nasolabial fold
- Lower lip droop
- Idiopathic (Bell's palsy)
- Reactivated varicella zoster/herpes simplex
- Lyme disease (first manifestation); may be bilateral
- Otitis media in children
- Local trauma
- Various viruses
- No neuroimaging/no routine labs
- Lyme disease blood testing (two-tier; if negative, retest in one week)
- Empiric doxycycline if high risk for Lyme disease (amoxicillin as alternative)
- Corticosteroids for all cases except Lyme; most benefit if started in first three days
- Valacyclovir if symptoms are severe and Lyme test is negative
- Artificial tears
- Ensure follow-up, either ENT or neurology
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