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原文題目(出處)： Management of Bell's palsy: A report of 2 cases 原文作者姓名： JCDA 2008;74:823-7
通訊作者學校： Araujo
報告者姓名(組別)： Intern A組 蕭建志 報告日期： 98.1.16
內文：
z Bell’s palsy is a neuropathy of the peripheral seven cranial nerve, usually resulting from traumatic, compressive, infective, inflammatory or metabolic abnormalities
z Patients generally experience rapid onset of unilateral facial palsy and often describe numbness or stiffness, although no actual sensory loss occurs. Affected patients are usually unable to close their eyes. Facial appearance becomes asymmetric, and saliva dribbles down the angle of the mouth
z The condition is named after Dr. Charles Bell, who, in 1821, described complete facial palsy
z Bell’s palsy is generally a unilateral disease, affecting both sides of the face equally. It is typically unilateral and can be complete or partial
z The pathogenesis of Bell’s palsy remains controversial. Acute inflammation and edema of the facial nerve are thought to lead to entrapment of the nerve in the bony canal (especially in the labyrinthine segment), which leads to compression and ischemia
z An inflammatory process surrounds the nerve fibres. Many viruses, such as HIV,Epstein-Barr virus and hepatitis B virus have been suspected in initiating this inflammation, but herpes simplex virus (HSV) is the most frequently implicated
z HSV has been identified in the endoneural fluid, posterior auricular muscle and saliva by polymerase chain reaction in patients with Bell’s palsy
z According to one hypothesis, HSV, dormant in the geniculate ganglion cells, becomes reactivated and replicates, causing inflammation, primarily in the geniculate ganglion and in the labyrinthine segment of the facial nerve. These inflammatory events (evident on MRI) result in entrapment and ischemia, which lead to neurapraxia or degeneration of the facial nerve distal to the meatal foramen
z Increased capillary permeability leads to exudation of fluid, edema and compression of the microcirculation of the nerve, which may be responsible for the vascular ischemia
z Treatment of Bell’s palsy is controversial, because as many as two-thirds of patients recover spontaneously. Corticosteroids alone or associated with antiviral agents have been recommended. Adour reported that patients with Bell’s palsy treated with acyclovir and prednisone experience a more favourable recovery and less neural degeneration than patients treated with placebo plus prednisone Case Reports
z Case 1
A 12-year-old girl with left hemifacial palsy over the past 15 days was referred to the oral and maxillofacial surgery department at Hospital de Base, Bauru, Sao Paulo, Brazil, by her pediatrician. She denied any type of facial trauma or systemic alteration. Although no diagnosis was made by the doctor, an antibiotic was prescribed and
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she had been taking it for the last 7 days without any improvement.
Her mother reported that the girl had been at a school camp for 2 weeks before the first signs of palsy, severe headache, dizziness and fever
Clinical examination revealed restricted movement of both the superior and inferior lips and in the left superior palpebra and left eyebrow region, associated with moderate pain around the left ear. The patient was diagnosed with hemifacial Bell’s palsy caused by a viral infection, although no HSV or herpes zoster lesions were present. She was prescribed acyclovir, 200 mg, every 4 hours, vitamin B complex every 12 hours and artificial tears during the day. She was advised to start facial physiotherapy exercises combined with warm water compresses and to keep the left eye closed with tape or a sleep mask during the night to avoid conjunctive dryness. After 28 days of medication, the facial palsy disappeared. The patient was seen weekly during the first month, then monthly for 1 year, and no signs of recurrence were noted
z Case 2
An 11-year-old girl, who was the roommate of the patient described above during the school camping vacation, exhibited left hemifacial palsy that had been detected 6 days before her first appointment. She described severe pain about 10 mm anterior to her left ear, just above the facial nerve trajectory During facial examination, the patient demonstrated an inability to close the right eye, to corrugate the left eyebrow or to move her lips. The patient was prescribed acyclovir, 200 mg every 4 hours and vitamin B complex every 12 hours for 28 days and artificial tears during the day. The patient recovered normal facial function, and after 1 year of follow-up, facial movements were satisfactory
Discussion
z differential diagnosis of Bell’s palsy: unilateral central facial weakness, Ramsay Hunt syndrome, Lyme neuroborreliosis, tumours, diabetes mellitus, sarcoidosis, weight loss, visual changes, vertigo and weakness or numbness
z Diagnosis of Bell’s palsy depends on
1. clinical signs, symptoms and evaluation to exclude other possible causes of facial paralysis
2. Laboratory investigations and imaging are carried out to detect the origin of the paralysis
3. lumbar puncture, IgG and IgM antibody tests and cerebral spinal fluid cell count to detect intracranial pressure and inflammation
4. MRI and CT to locate an intracranial lesion or hemorrhage 5. Lyme titre test to rule out Lyme disease
6. acetylcholine-receptor antibody test for myasthenia gravis
z Patients should be advised to use artificial tears to keep the eyes moist and prevent exposure keratitis. During the day, sunglasses are indicated, and dirty, noxious fumes should be avoided. During sleep, an ophthalmic ointment should be used
z Bell’s palsy does not usually recur; however, if it does, particularly bilaterally z Patients who have persistent clinical signs without improvement in facial paresis
after 4 weeks, require further investigation. A detailed history and thorough clinical examination should be carried out in those patients. Early recognition of signs and symptoms inconsistent with Bell’s palsy is important to avoid misdiagnosis. If the patient does not recover within the expected timeframe,
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imaging must be performed, such as CT or MRI
z Many clinical trials have evaluated acyclovir with or without prednisone for the treatment of Bell’s palsy: Adour and De Diego
z The use of steroids for Bell’s palsy in adults is considerable controversy even some studies have examined the usefulness of corticosteroids in the treatment of Bell’s palsy those have been limited by small sample size and lack of randomization, controls and blinding
z There is even less evidence for using steroids to treat Bell’s palsy in children Children are more vulnerable to the side effects of corticosteroids, particularly their effect on growth, immunity and adrenal suppression. A side effect of corticosteroids unique to children is growth suppression, which can be reduced by prescribing the medication on alternate days
z Boulloche and others carried out a retrospective review of 40 patients aged 1–16 years with acute facial nerve palsy. Patients who received steroids did not have better outcomes than those who did not receive steroids; similar findings were revealed by Dhiravibulya. Given the natural history of spontaneous recovery in most pediatric patients, steroid therapy is currently not indicated In the cases described above, we preferred to avoid steroids and prescribe antiviral agents associated with vitamin B
題號 題目
1 Which virus is the most frequently implicated about Bell’s palsy?
(A) HSV (B) HBV (C) EBV (D) HCV
答案( A ) 出處：ORAL&MAXILLOFACIAL PATHOLOGY P.741
題號 題目
2 Which one is the most frequenctly of Bell’s palsy?
(A) Mid-aged male (B) Old Male (C) Old Female (D) Mid-aged female
答案( D ) 出處：ORAL&MAXILLOFACIAL PATHOLOGY P.742
