Description
- Peripheral facial nerve weakness (cranial nerve VII) may be partial or complete, usually unilateral
ICD-9 Codes
- 351.0 Bell’s palsy
Incidence/Prevalence
- Highest incidence of Bell’s palsy between ages 15-45 years
- Annual incidence 25-32 per 100,000
Causes and risk factors
- Idiopathic
- Infections may be responsible for many cases
-Herpes simplex virus
-Varicella-zoster virus reactivation
-Lyme disease
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- Diabetes mellitus
- Third trimester of pregnancy
Complications
- Corneal drying, corneal abrasion
- Chronic spasm of facial muscles (synkinesia) or blepharospasm
- Anxiety and depression related to appearance
History
- Symptoms
-Facial weakness
-Unilateral loss of taste sensation
-Hyperacusis (sensitivity to sound)
-Face feels stiff or pulled to one side
- Abrupt onset, maximum weakness by 48 hours
- Pain behind or in front of ear may precede onset of weakness
- Questioning about earlier development of rash should be done if patient has been in region endemic for Lyme disease or has had a tick bite
- Impact
-Difficulty with eating or drinking
-Difficulty with facial expressions
-Drooling
Physical
- Peripheral facial nerve weakness
-Can involve all muscles of facial expression
-Greater involvement of lower face
- Look for manifestations of Lyme disease (erythema migrans)
- Clues suggesting peripheral lesion of Bell’s palsy rather than central lesion (such as stroke) include Inability to raise eyebrow to wrinkle forehead
-Involvement of eye closure on ipsilateral side
-Hyperacusis due to peripheral nerve involvement of stapedius muscle
-Sense of taste may be decreased on ipsilateral side
- Check external ear canal on affected side for vesicles implicating Ramsay Hunt syndrome
- Look for other neurologic signs to suggest central nervous system cause such as stroke
-Other cranial nerve deficits
-Arm and/or leg paralysis
-Aphasia
- Additional cranial nerve deficits may be seen in Bell’s palsy
Rule out
- Secondary causes of peripheral facial weakness
-Infection
- Lyme disease
- Ramsay Hunt syndrome (zoster of geniculate ganglion)
- Infectious mononucleosis
- HIV infection
-Tumors including
- Parotid gland tumors
- Cholesteatoma
- Recurrent skin cancer
-Occult malignancy of facial nerve
-Guillain-Barre syndrome
-Sarcoidosis
- Central nervous system diseases
- Bilateral facial paralysis (facial diplegia) more likely in Lyme disease
-Acute inflammatory polyradiculoneuritis (Guillain-Barre syndrome)
-Myasthenia gravis
-Sarcoidosis
Testing to consider
- No testing indicated in most cases of peripheral facial palsy
- MRI with contrast can rule out tumor, stroke, multiple sclerosis, or other structural lesions
- Lyme titer
Prognosis
- Most patients recover completely, especially if partial paralysis or younger age
-Onset of recovery within three weeks in 85% and within three to five months in 15%
-Remission within 3 weeks in 55% and after three to six months in an additional 15%
-Full recovery less likely with increasing age
- 90% children <14 years old
- 84% ages 15-29 years
- 75% ages 30-44 years
- 64% ages 45-59 years
- 36% adults >60 years old
- Diabetes and pregnancy associated with lower recovery rate
- Four clinical factors may be associated with unfavorable outcome in Bell’s palsy patients treated with prednisolone
-Duration between onset and treatment longer than seven days
-Severe facial paralysis
-Hearing defect
-History of recurrence
Treatment
- Corneal protection may include lubrication (eyedrops or ointment) and eyelid taping
- For hyperacusis, earplug may be helpful
- Corticosteroids
-Hasten recovery and increase rates of complete recovery
-May be ineffective during pregnancy
- Antivirals have inconsistent evidence for Bell’s palsy but no benefit in highest-quality trials
- Vitamin B12 intramuscularly may be beneficial
- Acupuncture might improve outcomes
For complete references, see www.ebscohost.com/dynamed/.
This article originally appeared on Cancer Therapy Advisor
