OVERVIEW: What every practitioner needs to know
Are you sure your patient has facial nerve paralysis? What are the typical findings for this disease?
Facial palsy has an annual incidence of approximately 20 per 100,000. It has a favorable prognosis in most cases, but as many as 8,000 people in the United States each year are left with a permanent, potentially disfiguring facial weakness. The facial nerve is the 7th cranial nerve and has both sensory and motor components. The sensory portion controls taste, salivary and lacrimal glands. The motor portion controls the stapedius muscle in the middle ear and the muscles of facial expression.
The most important initial clinical task in evaluating a patient with facial palsy is to differentiate a central facial palsy from a peripheral palsy.
In central or upper motor neuron facial palsy, the upper part of the face or the forehead is spared because of bilateral innervation from the motor cortex to each CN VII nucleus.
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In Peripheral or lower motor neuron or Bell Palsy the entire side of the face is affected, as each CN VII innervates only the ipsilateral side.
Typical findings for facial nerve paralysis:
Sudden onset, unilateral facial weakness
Occasional periaural numbness or tingling
Inability to raise eyebrow on the affected side
Inability to tightly close the eyelid on the affected side
Absent or diminished nasolabial fold
Crooked smile with mouth drawn to unaffected side
Crying infants will have inability to close eye on the affected side
Hyperacusis (diminished tone in the stapedius muscle results in more prolonged movement of the ossicular chain by auditory stimulation).
Decreased lacrimation
Decreased taste
What caused this disease to develop at this time?
Causes for facial palsy may be genetic or acquired.
Congenital facial palsy:
Occurs in approximately 2 per 1000 children
Usually related to birth trauma, including forceps delivery, prolonged labor, birth weight greater than 3500g
Certain rare genetic syndromes, often bilateral
Acquired facial palsy:
Lyme disease
Herpes Simplex virus (Ramsey Hunt syndrome with periauricular vesicles)
Other Viruses – Varicella, HHV6, Mumps, Coxsackie, Adeno, EBV
Acute Otitis Media
Trauma
Malignancy
Hypertension associated
Idiopathic or Bell Palsy
Guillan Barre Syndrome (bilateral)
What laboratory studies should you request to help confirm the diagnosis? How should you interpret the results?
History and Physical exam:
Is the forehead spared or involved?
Is the palsy present since birth? If congenital look for known traumatic risk factors (forceps etc), facial eccchymosis or craniofacial anomalies for a syndromic cause.
Is there h/o facial trauma?
Is there an acute ear infection or mastoid tenderness?
Are there systemic symptoms – headache, meninigsmus, papilledema, rash (typical Lyme rash)?
Did the facial palsy occur during warm months?
Is the patient from an endemic area for Lyme?
Is there recurrent facial palsy – with fissured tongue, facial edema, similar family history? These findings are associated with the Melkersson Rosenthal Syndrome.
Is there history of recurrent, ipsilateral facial palsy, suggesting neoplasm?
Is there prolonged recovery time (> 6 months) suggesting anatomic problem or neoplasia?
Is there a history of hypertension?
Would imaging studies be helpful? If so, which ones?
In congenital facial nerve palsy, computed tomography (CT) scan of temporal bone with thin internal auditory canal can be helpful to assess middle and or inner-ear anomalies and to rule out absence or dysplasia of the facial nerve.
In acquired facial palsy, magnetic resonance imaging (MRI), with and without contrast, is helpful to look at brain stem, pons, the cerebellopontine angle and the internal auditory canal.
Patients with facial nerve contrast enhancement have a slower recovery than those without enhancement (19.3 versus 9.5 weeks).
Confirming the diagnosis
Is the forehead spared or involved? If forehead is spared, suggesting a central facial nerve palsy, the patient needs immediate imaging and evaluation for stroke.
Is the palsy present since birth? If congenital look for any known traumatic risk factors (forceps etc), facial eccchymosis or craniofacial anomalies for a syndromic cause – a CT scan of the temporal bone should be obtained to assess facial nerve anatomy.
Is there a history of facial trauma? If so, obtain a CT of the temporal bone.
Is there an acute ear infection or mastoid tenderness? If so, myringotomy should be performed and antibiotics provided.
If vesicles are present check for HSV and treat with anti viral therapy if suspected.
Are there systemic symptoms – headache, meninigsmus, papilledema, rash (typical Lyme rash) do an LP and check Lyme titers on serum and CSF, treat with IV Ceftriaxone if there is evidence of CNS Lyme.
Did the facial palsy occur during warm months? If so, check Lyme titers.
Is the patient from an endemic area for Lyme? If so, check Lyme titers.
Recurrent facial palsy with fissured tongue, facial edema, similar family history suggests Melkersson Rosenthal Syndrome.
Is there history of recurrent, ipsilateral facial palsy? If so, obtain imaging to r/o neoplasm.
Is there prolonged recovery time (> 6 months)? If so, obtain imaging.
Is there a history of hypertension? If so, treat the hypertension.
If you are able to confirm the patient has facial nerve paralysis, what treatment should be initiated?
Treatment of facial nerve paralysis
Medical:
Prophylaxis to avoid ophthalmologic complications – ocular lubricants or artificial tears, patching.
If there is an infectious etiology of facial nerve palsy (OM, HSV, VZV, Lyme), treat with antibiotics or antiviral therapy directed against the underlying cause. In Lyme endemic area, warm summer months, typical rash, systemic symptoms consider empirical oral treatment for Borrelia pending the results of titers. Facial palsy in the context of Lyme disease may be an indication of CNS Lyme, particularly if there is headache or other neurological symptoms. The signs and symptoms of meningitis in children with facial nerve palsy due to Lyme disease may be subtle and an LP is often indicated, with CSF sent for Lyme antibodies, as this will influence the nature and duration of treatment.
According to the “Red Book” of the American Academy of Pediatrics, facial palsy attributed to Lyme Disease should be treated as follows:
-For Isolated Facial nerve palsy: 8 years of age or older: Doxycycline, 100 mg, orally, twice a day for 21-28 days.
-Younger than 8 years of age or unable to tolerate doxycycline: Amoxicillin, 50 mg/kg per day, orally, divided into 3 doses (maximum 1.5 g/day) for 21-28 days.
If the facial palsy is associated with meningitis or encephalitis:
-Ceftriaxone sodium, 75-100 mg/kg, IV or IM, once a day (maximum 2 g/day) for 21-28 days.
Treatment of idiopathic facial nerve palsy/Bell palsy:
-Steroids.
A Practice parameter from the American Academy of Neurology on the use of steroids in cases of Bell palsy concluded that: “Based on the pooled result of Class I and Class II studies and a relatively benign side effect profile, we conclude that steroids are safe and probably effective in improving facial functional outcomes in patients with Bell Palsy”.
In the literature review, the most commonly reported regimen was 1 mg/kg of oral prednisone, up to 70 mg per day, split into twice-daily dosing. The starting dose was continued for 6 days, then tapered off over a subsequent 4 days.
Acyclovir:
Regarding the use of acyclovir, the practice parameter concluded: “Based on the result of a single class II study and a relatively benign side effect profile, we conclude that acyclovir (combined with prednisone) is safe and possibly effective in improving facial functional outcomes in patients with Bell Palsy.” It should be noted that these studies did not include many children with idiopathic facial nerve palsy, thus there is little evidence-based support for the use of acyclovir in children with Bell palsy.
In the studies reviewed, the dose of acyclovir ranged from 1,000 mg a day for 5 days to 2,400 mg a day for 10 days.
Patients with Ramsay-Hunt syndrome (herpes zoster oticus), with vesicles in the external ear canal, face or oral cavity are generally treated with antiviral therapy and steroids, in combination.
Surgical:
Facial palsy secondary to acute otitis media – myringotomy with or without tube insertion.
Mastoiditis – Antibiotics, mastoidectomy.
Surgical reconstruction in trauma .
What are the possible outcomes of facial nerve paralysis?
Prognosis of facial nerve paralysis
Congenital traumatic facial nerve palsy resolves spontaneously in 90% of patients within 4 weeks.
Recovery rates of idiopathic facial nerve palsy in children range from 70% to 90%. Most patients with Bell palsy recover without treatment, 71% achieve complete recovery, 84% achieve near normal function. The prognosis for good recovery is better in cases when the paresis is only partial.
Facial nerve palsy has a broad differential diagnosis. In idiopathic causes, where no cause is found, therapy with prednisone with or without an antiviral medication should be started within 72 hours. This is especially important in cases of complete paresis (slack face, with assymetry evident at rest). The median time to recovery varies with etiology, but overall prognosis is good.
What is the evidence?
“Infectious Diseases”. .
“Lyme Disease (Lyme Borreliosis, Borrelia burgdorferi Infection)”. Red Book. 2009. pp. 430-435. (The “Red Book” a publication of the American Academy of Pediatrics,discusses pediatric infectious diseases, their presentation, diagnostic tests and treatment. It is worth noting that while the Red Book guidelines on treatment of Lyme disease distinguish between the treatment of isolated facial palsy and Lyme meningitis/encephalitis, it is not emphasized that facial palsy can be a manifestation of Lymemeningitis.)
Burgio, DL, Siddique, S, Haupert, M. “Magnetic resonance imaging of the facial nerve in children with idiopathic facial paralysis”. Otolaryngol Head Neck Surg.. vol. 122. 2000. pp. 556-559. (Generally, imaging is NOT indicated in cases of facial nerve palsy. If multiple cranial nerves are involved or other focal neurological findings are present, MR imaging is indicated (CT imaging of the brainstem is greatly compromised by the bony structures surrounding the brainstem).)
Grogan, PM, Gronseth, GS. “Practice parameter: Steroids, acyclovir, and surgery for Bell's palsy (an evidence-based review): Report of the Quality Standards Practice parameter: Steroids, acyclovir, and surgery for Bell's palsy Subcommittee of the American Academy of Neurology”. Neurology. vol. 56. 2001. pp. 830-836. (This practice parameter discusses treatment options for Bell palsy i.e.idiopathic facial nerve palsy. The number of studies reviewed in this guideline that focus on children is very limited.)
Nigrovic, LE, Thompson, AD, Fine, AM. “Clinical predictors of Lyme disease among children with a peripheral facial palsy at an emergency department in a Lyme disease-endemic area”. Pediatrics. vol. 122. 2008. pp. e1080-1085. (This study found that facial palsy in children was more likely to be dueto Lyme disease if: onset of symptoms occurred from June to October (Lyme disease season), the facial palsy was associated with fever and a history of headaches and there was no history of previous herpeticlesions.)
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