Facial Nerve Palsy. James M. Gilchrist

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1 Facial Nerve Palsy James M. Gilchrist 7 Abstract Facial neuropathy is the most common cranial neuropathy, due to its extensive course and multiple sites of potential injury. The causes of facial neuropathy are many, but 70% are diagnosed as Bell s palsy, an idiopathic syndrome but increasingly being associated with herpes simplex virus infection as the cause of the majority of cases. Ramsay Hunt syndrome (herpes zoster oticus) is the second most common cause. Facial neuropathy causes weakness of the muscles of facial expression on the ipsilateral side, and can be distinguished from a central, or upper motor neuron, caused by the involvement of forehead muscles. Taste, hearing, salivation, lacrimation, and sensation over the ipsilateral ear and the face may also be disturbed. Diagnosis can be confirmed by electrodiagnostic testing or MRI but is often not necessary. Treatment is directed at the underlying cause. In cases of Bell s palsy a short course of steroids has been shown effective, if started within 72 h of onset. Treatment with antiviral agents against herpes virus is probably best reserved for patients with severe or complete facial neuropathy or those with Ramsay Hunt syndrome. Keywords Antiviral agents Bell s palsy Herpes simplex Herpes zoster Lyme Ramsay Hunt syndrome Seventh cranial neuropathy Steroids J.M. Gilchrist, MD ( ) Neurology, Warren Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI, USA jgilchrist@lifespan.org K.L. Roos (ed.), Emergency Neurology, DOI / _7, Springer Science+Business Media, LLC

2 134 J.M. Gilchrist Introduction The facial nerve, also known as the seventh cranial nerve, is the most commonly diagnosed cranial neuropathy. The reasons for this lie in its anatomy and its obviousness. The facial nerve has both an intracranial and an extracranial course, taking three significant bends along the way and traversing several potential points of difficulty (lateral pons, cerebellopontine cistern, the bony facial canal which it shares for part of the way with the acoustic nerve, the inner ear, the parotid g land). And facial nerve palsy is the absolute manifestation of being in your face. The facial nerve provides innervation for muscles of facial expression, which is a primary mode of expressing emotion in humans and an important aspect of nonverbal communication, as well as a major aesthetic component of beauty. As such, we are especially attuned to facial movement and any asymmetry is immediately evident and upsetting. Patients do not sit at home and wait out a new facial palsy. They set out for the emergency room soon after onset and with considerable anxiety. Epidemiology Facial neuropathy is a common neurologic syndrome, and 70% will be diagnosed as Bell s palsy [1 ]. The annual incidence of Bell s palsy is 25 per 100,000 [ 2 ] with a lifetime risk of 1 in [ 3 ]. Males and females are affected equally and the frequency per decade of life is remarkably similar between age 10 and over 70 years of age [ 2 ]. There is no preference between right and left sides, though bilateral involvement is rare, at 0.3 2% [4 ]. Ramsay Hunt syndrome is the second most common cause of facial neuropathy and can occur in children (16.7% of unilateral facial palsies) and adults (18.1% of facial palsies) with nearly equal frequency, though less so in children under the age of 6 [ 5 ]. Zoster sine herpete looks to be especially common in children between 6 and 15 years of age and may account for over a third of all facial neuropathies in that age group [ 6, 7 ]. Pathophysiology and Pathogenesis Facial nerve palsy cannot truly be understood without at least some knowledge of the anatomy of the seventh cranial nerve (Fig. 7.1 ). The motor root of the facial nerve arises in the facial nucleus in the lateral pons. Fibers leaving the nucleus execute a loop (the internal genu of the facial nerve) around the nucleus of the abducens nerve, traveling medially from below to above the sixth nerve nucleus before exiting at the pontomedullary junction. The motor root then traverses the cerebellopontine cistern to enter the internal acoustic canal. The sensory root of the facial nerve is separate from the motor root between the brainstem and the internal acoustic canal and is often called the nervus intermedius. Within the nervus intermedius are sensory fibers which end in the spinal nucleus of cranial nerve V, and parasympathetic fibers. In the internal acoustic canal, the now-whole facial nerve is accompanied by the eighth cranial nerve. The nerves travel to the meatal foramen ( porous acusticus ), which is divided into bony compartments, to then enter the facial canal, also called the fallopian canal. The meatus is the narrowest portion of the entire facial canal, less than 0.7 mm [ 8 ]. The facial nerve then enters the labyrinthine portion of the facial canal, so called because it is close to the superior semicircular canal. The labyrinthine canal ends at the geniculate ganglion, where the cell bodies of the sensory and parasympathetic neurons are located. The greater petrosal nerve branches off at the geniculate ganglion to head to the sphenopalatine and pterygopalatine ganglia, from whence it supplies the lacrimal gland with parasympathetic innervation. From the geniculate ganglion, the facial canal takes its first external genu, and is called the tympanic segment. The nerve to the stapedius muscle branches off within the tympanic canal. The tympanic segment ends as the facial canal makes its second external bend, this time at a 90 angle. The final intracranial part of the facial canal is called the mastoid segment and proceeds in a vertical descent to the stylomastoid foramen where the facial nerve becomes extracranial.

3 7 Facial Nerve Palsy 135 Fig. 7.1 Anatomy of the seventh cranial nerve The chorda tympani branches off in the mastoid segment and then enters the tympanic cavity before joining the lingual nerve. It sends preganglionic parasympathetic fibers to the sublingual and submaxillary glands. The chorda tympani also conveys taste from the anterior two-thirds of the tongue. Once the facial nerve is extracranial, it divides into the posterior auricular branch which supplies sensation to the auricle and pinna of the ear, although it also has motor fibers. Other terminal branches control muscles of facial expression, as well as branches to the digastric and stylohyoid muscles. The potential causes of facial neuropathy are protean (Table 7.1 ), as are the related pathophysiologies. There is mounting evidence that Bell s palsy is associated with herpes simplex (HSV) infection. McCormick first postulated a connection with HSV infection in 1972 [ 9 ], and several lines of evidence support that up to 79% of Bell s palsy is caused by reactivated HSV infection in the geniculate ganglion [ 10 ]. Increased rates of HSV genome fragments by PCR were seen in the saliva of patients with Bell s palsy [ 11 ], and PCR also identified such fragments in human geniculate ganglia at autopsy [ 12, 13 ]. Murakami found active HSV sequences in the endoneurial fluid of the facial nerve in patients with Bell s palsy [ 14 ], and facial neuropathy was induced in animals by reactivating HSV [ ]. Reactivation of the HSV virus presumably causes inflammation of the facial nerve in the facial canal, initially causing demyelination, but if severe, causing axonal damage and Wallerian degeneration distal to the lesion [19 ]. Ramsay Hunt first described the condition which bears his name in 1907 [ 20 ]. Ramsay Hunt syndrome is defined as a peripheral facial neuropathy accompanied by an erythematous vesicular rash of the ear (herpes zoster oticus) or mouth [20 ]. The infection involves the contiguous facial nerve in the tympanic segment, leading, as in

4 136 J.M. Gilchrist Table 7.1 Causes of unilateral seventh cranial neuropathy Relatively common Bell s palsy (idiopathic) Herpes simplex virus Ramsay-Hunt syndrome (herpes zoster) Lyme Zoster sine herpete Trauma Diabetes mellitus Pregnancy Guillain Barré syndrome Sarcoid Neoplastic meningitis Pontine infarct Pontine hemorrhage Multiple sclerosis Brainstem tumor Facial neuropathy from forceps/birth trauma Acoustic neuroma Relatively less common Pontine Encephalitis Abscess Congenital/postnatal Mobius syndrome Hemicranial microsomia Congenital lower lip paralysis Kawasaki disease Albers-Schoenberg (osteopetrosis) Infantile hypercalcemia Cardiofacial syndrome Tumor Meningioma Cholesteatoma Metastatic Neurinoma Parotid tumor Meningitis Infectious Bacterial Fungal Tuberculous Syphilis Parasitic (trichinosis, neurocystercercosis) Inflammatory Leukemia (children) Infections HIV seroconversion Osteomyelitis of skull base Otogenic infections Parotitis/abscess Mastoiditis Leprosy Poliomyelitis Mycoplasma Influenza Miscellaneous Benign intracranial hypertension Melkersson Rosenthal Amyloidosis Wegener s granulomatosis Polyarteritis Sjogren s syndrome HTLV-1 Hereditary neuropathy with pressure palsies (HNPP) Familial Bell s CIDP Charcot-Marie-Tooth Histiocytosis X Interferon therapy Sclerosteosis Ethylene glycol intoxication Wernicke Korsakov syndrome Stevens-Johnson syndrome Bell s palsy, to inflammation, edema, demyelination, and potentially, axonal damage. Ramsay Hunt syndrome can be seen in the absence of a rash (zoster sine herpete) when accompanied by either a fourfold rise in varicella zoster virus (VZV) antibody or detection of VZV DNA [ 20 ]. This may occur in anywhere from 2.4% to 19% [5, 21 ] of patients who otherwise might have been thought to have Bell s palsy. The cause of Lyme facial neuropathy is likely not from meningitis. Halperin examined the CSF of 31 patients with Lyme facial neuropathy [ 22 ]. Only 11 had CSF pleocytosis, and nine had elevated protein concentration, and he suggested that meningitis might occur concomitantly with facial neuropathy but not as a cause of facial neuropathy [22 ]. Clinical Features Facial neuropathies can affect either sex and occur at any age [ 2 ]. Facial neuropathies are nearly always unilateral [ 4 ], with only 1 2%

5 7 Facial Nerve Palsy being bilateral. The most obvious finding on examination is facial paresis or paralysis ipsilateral to the neuropathy, involving all muscles of facial expression, although to potentially varying degrees. This is in contradistinction to facial weakness from a lesion above the level of the pontine facial nucleus (such as from a stroke), which will cause weakness of contralateral lower facial muscles only, sparing the frontalis muscle. The facial nucleus receives cortical innervation for muscles of the upper face from both cerebral hemispheres, but only from the contralateral cerebral hemispheres for lower facial muscles. Facial neuropathies proximal to or at the level of the geniculate ganglion will also cause hyperacusis due to paralysis of the stapedius muscle, but there will not be any hearing loss from an isolated facial neuropathy. In addition, salivation and lacrimation will be hindered or lost altogether due to damage to parasympathetic fibers. Lesions at or proximal to the second external genu (i.e., in the tympanic segment of the facial canal) will result in dysgeusia and xerostomia from damage to the chorda tympani. Sensation over the ipsilateral ear lobe will be affected in any facial neuropathy proximal to the stylomastoid foramen. Subjective and/or objective numbness over the paretic portions of the face is also not uncommon [ 2 ]. This is presumed due to connections between the maxillary branch of the trigeminal nerve and the sphenopalatine ganglion [ 23 ]. Pain early in the course is present in a significant minority of patients with Bell s palsy [ 2 ] and a high proportion of patients with Ramsay-Hunt disease [ 20 ]. As the orbicularis oculi will be weak, inhibiting complete eye closure, protection of the cornea is important, especially at night when the patient is asleep. Eye lubrication and taping the eye shut should be instituted immediately in any patient with incomplete eye closure. Patching the eye alone is not appropriate, especially with gauze, as that will wick away lacrimation, and hasten corneal injury. Other cranial nerve abnormalities, such as hearing loss, tinnitus, dysphagia, dysarthria, and diplopia, often accompany secondary causes of facial neuropathy and require further evaluation. In Ramsay Hunt syndrome, facial weakness reaches maximum by 1 week after onset with 137 severe to complete paralysis in 52% of adults and 44% of children [ 5 ]. Age over 50 years, complete paralysis and lack of nerve excitability are poor prognostic factors [ 24 ]. Between 80% and 85% will have a good recovery [ 5 ]. Unlike Bell s palsy, other cranial neuropathies (VIII, IX, or X) are frequent, with up to 53% of adults suffering hearing loss, which did not improve in 38% [ 5 ]. Tinnitus and vertigo are also common [ 5 ]. Cranial neuropathies occur in 5 10% of patients with Lyme disease and 80% are facial neuropathies [25 ]. Lyme disease is a relatively frequent cause of bilateral facial neuropathy. Unilateral or bilateral facial palsies are the most frequent neuropathic manifestation, accounting for 50% of patients with neurologic involvement [26 ]. Residual symptoms of Lyme-associated facial neuropathy are uncommon, with complete or near-complete recovery in over 90%, even without treatment [ 22, 27 ]. Peripheral Lyme serologic testing is abnormal in 90% of patients at the time of facial neuropathy but can also become positive subsequently [ 22 ]. Western blots are usually negative, consistent with facial neuropathy being a very early manifestation of Lyme disease, and erythema migrans is also uncommon [ 22 ]. The time course of recovery from facial palsy is dependent on the type and degree of pathophysiologic lesion. A neurapraxic, or purely demyelinative, lesion will recover within days to weeks as the Schwann cell remyelinates the affected segment. More severe lesions resulting in axonal damage and distal Wallerian degeneration will take longer to recover function as nerve regeneration will be required. The regeneration may well be incomplete, resulting in the major sequelae of facial palsy, which are persistent paresis or paralysis, corneal injury secondary to incomplete eyelid closure, facial muscle contracture, and synkinesis [28 ]. Synkinesis is the phenomenon whereby the intended activation of one muscle will result in contraction of other muscles as well. This cocontraction may be due to either aberrant nerve fiber regeneration or to ephaptic transmission. Facial synkinesis can involve motor nerve fibers as well as fibers to the lacrimal and salivatory glands, resulting in the so-called crocodile tears phenomenon, in which gustatory salivation

6 138 J.M. Gilchrist causes tearing as well. Facial synkinesis is seen in the majority of patients with Bell s palsy who have evidence of axonopathy [ 28 ]. Diagnosis The diagnosis of facial palsy does not require sophisticated testing and should be possible using bedside acumen. The most common diagnostic question for acute unilateral facial weakness is between facial neuropathy and a stroke, and this should not be clinically difficult. Upper motor neuron, or central, facial weakness spares the forehead, does not cause hyperacusis, dysgeusia or pain, and usually involves symptoms and signs beyond the face. Examination of the ear, tympanic membrane, and mouth for vesicles is important and an ELISA screen for Lyme disease is essential in any area endemic for the Borrelia burgdorferi -bearing deer tick, Ixodes scapularis. Lumbar puncture is not routinely indicated unless there are complicating factors, such as multiple cranial neuropathies, significant meningismus, or other neurologic signs or symptoms implying involvement beyond the facial nerve. The electrodiagnostic methods most commonly used to study the facial nerve are direct facial motor nerve conduction studies (electroneurography). Most patients referred to the EMG laboratory because of a facial paresis are sent for a prognosis, which is directly related to whether the facial nerve lesion is demyelinative or axonopathic. Electrodiagnostic studies are quite useful for making that determination but are limited because Wallerian degeneration of motor nerve fibers takes 5 8 days after axonal injury and NCSs will be of little prognostic value before that time [ 29 ]. Amplitude of the direct motor nerve evoked response 5 7 days after onset is probably the best available method [ ]. When the CMAP amplitude is less than 10% of that on the healthy side, maximum recovery will be delayed 6 12 months and function will be moderately or severely limited. If the amplitude is 10 30% of the healthy side, recovery may take 2 8 months with mild to moderate residua. If the CMAP amplitude is >30% of normal, full-complete recovery can be expected at 2 months after onset [ 33 ]. Latency of the direct facial motor nerve stimulation is not as useful as amplitude measurement [34 ]. When done 5 7 days after onset, three types of evoked responses are found: normal, which virtually assures patients of a complete recovery without aberrant recovery; prolonged latency compared with the opposite side, with frequent good recovery but some chance of synkinesis; and no response, with high incidence of synkinesis and some patients with no recovery. The blink reflex is the electrical correlate of the bedside corneal reflex [32 ]. The blink reflex differs from direct facial nerve study in that it examines the trigeminal nerve and the pons in addition to the facial nerve, and assesses proximal segments of the facial nerve inaccessible to the direct stimulation technique. Facial motor synkinesis can be assessed by expanding the set up for the blink reflex to also include recording electrodes over the orbicularis oris or other facial muscles [32 ]. The blink reflex as a prognostic method has not been particularly helpful in that it offers little beyond direct facial nerve studies and is limited by the same time constraints. At this time there is no electrodiagnostic technique which reliably predicts prognosis in Bell s palsy within the first h after onset. CMAP amplitude comparing side-to-side difference at day 5 7 after onset appears to be the most reliable parameter for ultimate prognosis [ 30, 32 ]. MRI with gadolinium enhancement allows imaging of the abnormal facial nerve but is not usually indicated in isolated, unilateral facial neuropathy. A very high percentage of Bell s palsy patients will show enhancement, as will 50% of Ramsay Hunt disease patients [ 35 ]. Enhancement can also be seen in Lyme-related facial palsy. The only diagnostically reliable abnormality is enhancement in the distal intracanalicular and labyrinthine segments [ 36 ], but other than confirming the diagnosis, enhancement provides no indication of severity or prognosis [35, 37 ]. Enhancement can persist for weeks or months after resolution of the facial palsy. For patients suspected of secondary causes of facial neuropathy, MRI may be indicated to assess for

7 7 Facial Nerve Palsy pontine lesions, cerebellopontine cistern and internal acoustic canal masses, and meningitis. Differential Diagnosis As discussed above, the primary initial differential is between facial neuropathy and a stroke. Once this has been clarified in favor of facial neuropathy, the differential is between Bell s palsy, an idiopathic facial neuropathy, and secondary causes of facial neuropathy (see Table 7.1 ). Bell s palsy accounts for up to 70% of facial neuropathy [1 ]. As mentioned above, clues to secondary causes include involvement of other cranial nerves (with the exception of mild subjective or objective sensory loss over the cheek), and signs or symptoms of other neurologic involvement. Concomitant medical conditions associated with facial neuropathy (see Table 7.1 ) would also be reasons to look beyond Bell s palsy. The most common secondary cause is Ramsay Hunt syndrome from herpes zoster oticus, which may account for up to 18% of facial neuropathies [5 ], and will be mistaken for Bell s palsy if the external auditory canal, mouth, and tongue are not examined for vesicles [ 20 ]. The presence of bilateral facial neuropathy, while uncommon, provides a further clue to etiology. Bell s palsy remains the most common cause [4 ], but Guillain-Barré and Miller Fisher syndromes need to be considered, as do HIV infection, meningitis, a variety of pontine pathologies, and Lyme disease [ 4 ]. Treatment The pathophysiologic theory that Bell s palsy is caused by inflammation in the facial canal, presumably secondary to HSV reactivation, which leads to demyelination and, if severe, to axonal loss, has led to the hypothesis that steroids and/or antiviral agents will assist in the recovery from Bell s palsy and lead to lower long-term sequelae such as paralysis, paresis, and synkinesis. Until recently, the assessment of whether steroids or antivirals, or both, were beneficial in 139 Bell s palsy was hindered by few randomized trials with limited number of patients. In the latest Cochrane review of steroids in Bell s palsy, published in 2004, there were only four trials with a total of 179 patients [ 38 ]. No significant difference between steroids and nontreatment was found. Nearly the same conclusion was reached by the authors of a Cochrane review of antiviral agents in Bell s palsy [ 39 ]. They found only three randomized trials which met inclusion criteria, with a total of 246 patients. Benefit was again uncertain, as was harm. Three recent studies and a meta-analysis have helped to clarify the picture, although controversy remains. In 2007, Hato et al. [ 40 ] published a prospective, randomized, multicenter, placebocontrolled trial of valacyclovir and prednisone versus placebo and prednisone. The valacyclovir dosage was 1,000 mg/day for 5 days, and prednisone was 60 mg/day for 5 days, 30 mg/day for 3 days, and 10 mg/day for 2 days. The overall results indicated 96.5% of patients treated with both valacyclovir and prednisone recovered versus 89.7% for those treated with placebo and prednisone, which was significant at p < But the largest difference was in those patients with complete palsy, and if complete and severe palsy were grouped together, the absolute rate of improvement increased to 9.1% (as versus 6.8% in the entire group) [ 40 ]. Also in 2007, Sullivan et al. [ 41 ] published a prospective, randomized, placebo-controlled trial of Bell s palsy within 3 days of onset. There were four groups, receiving either 10 days of prednisolone, acyclovir, both, or placebo. The prednisolone was dosed at 25 mg twice daily, and the acyclovir was 400 mg five times daily. They analyzed the final outcome of 496 patients. In patients receiving placebo, 64.7% recovered by 3 months and 85.2% by 9 months. For steroid versus no steroid, 83% improved at 3 months versus 63.6%, for an odds ratio of 2.44, and 94.4% improved versus 81.6% at 9 months, an odds ratio of The antiviral outcome was different, with no perceived benefit: at 3 months, 71.2% on acyclovir and 75.7% not on acyclovir recovered, an odds ratio of 0.86; and at 9 months, 85.4% on acyclovir and 90.8% not on acyclovir recovered, an

8 140 J.M. Gilchrist odds ratio of They concluded that early treatment with prednisolone in Bell s palsy significantly improved the chance of recovery, but for acyclovir there is no evidence of a benefit of acyclovir given alone or an additional benefit of acyclovir in combination with prednisolone [41 ]. The benefit of prednisone was present in patients with moderate facial weakness as well as severe palsy [ 42 ]. In 2008, Engstrom et al. [ 43 ] published another prospective, double-blind, randomized, placebocontrolled trial of Bell s palsy within 72 h of onset. Patients were assigned to either placebo and placebo, prednisone 60 mg for 5 days plus placebo, valacyclovir 1,000 mg three times a day for 7 days plus placebo, or prednisone and valacyclovir. Eight hundred and thirty nine patients were assigned with 829 included in the intentionto-treat analysis. The primary endpoint was the time to complete recovery. There was a significant decrease in the time to completely recover in the patients who took prednisone compared to those that did not (hazard ratio of 1.40). However, there was no difference in time to complete recovery between those patients who took valacyclovir and those that did not (hazard ratio 1.01). At 12 months, 72% of patients given prednisone recovered versus 57% for those who did not, and 58% for those given just valacyclovir. Synkinesis was seen in 14% of the prednisone-treated group but was present in 29% of the nonprednisonetreated patients. Finally, in 2009, de Almeida et al. [ 44 ] published a meta-analysis of 18 studies, containing 2,786 patients, concerning corticosteroids and/or antiviral agents in Bell s palsy. Steroids were found to significantly reduce the risk of an unsatisfactory outcome (relative risk reduction of 0.69) with a number needed to treat to benefit one person of 11. Antiviral agents alone did not reduce the risk of poor outcome, but when combined with steroids, provided marginal benefit than steroids alone. These studies have confirmed the benefit of corticosteroids in the acute treatment of Bell s palsy, if initiated by 72 h after onset. However, they have engendered further debate about the role of antiviral agents. A reasonable course of action based on these studies would be to treat Bell s palsy with moderate paresis with steroids alone, while reserving antiviral treatment for those patients with severe to complete palsies [ 10 ]. Other treatments have been considered but remain controversial. A Cochrane review of acupuncture in Bell s palsy found six studies with 537 patients but was unable to reach any conclusion due to poor study quality [ 45 ]. Surgical treatment of Bell s palsy has followed a changeable course, with the preferred site of decompression and timing changing over time [ 46, 47 ]. May, once an ardent advocate of surgical decompression, changed his opinion to the belief it was of no benefit [48 ]. A more recent multicenter, prospective trial of surgical decompression via a middle cranial fossa exposure utilized electroneurography and needle electromyography to select patients [ 46 ]. Patients seen within 3 days were placed on steroids. At 14 days, those patients with total facial paralysis and >90% decrease in motor amplitude compared to the unaffected side, and no voluntary MUPs on needle electromyography, were offered surgery. Nineteen patients who met the criteria had surgical decompression within 14 days, and 18 had good recovery. Eleven patients declined surgery and four recovered to a satisfactory degree and seven had some recovery. Another seven patients had decompression surgery after 14 days, and fared similar to those who had declined surgery. The study was not randomized or blinded in any way, and the numbers are small. But it does bring back into consideration early surgical decompression in those patients with the worst prognosis [ 46 ]. There is a lack of prospective, randomized controlled trials in Ramsay Hunt disease. The largest retrospective trial used oral prednisone and intravenous acyclovir in 80 patients, divided by onset of treatment [ 49 ]. 75% of those treated within 3 days recovered completely, down to 48% when treatment was not started until days four through seven, and only 30% had complete recovery when treatment was delayed until after 7 days [ 20, 49 ]. Oral antiviral dosages differ from what is effective for HSV, requiring 3,000 mg/day of valacyclovir or 4,000 mg/day of acyclovir for 7 days for VZV, versus 1,000 mg/day of either for 5 days for HSV [10 ] and as they inhibit viral replication but do not destroy viruses, treatment must be initiated within 3 days to be effective [ 10 ].

9 7 Facial Nerve Palsy There are no prospective, randomized, controlled treatment trials for Lyme facial neuropathy. Oral antibiotics in a patient with Lyme facial neuropathy and normal CSF are appropriate [ 50 ]. Several oral and parenteral antibiotics are effective [25, 50 ]. The question of whether patients with Lyme facial neuropathy should have CSF examined is one of continuing debate and depends on whether oral or parenteral antibiotics are indicated if meningitis is present [ 50, 51 ]. If, in fact, all forms of this infection-except for clinically or radiographically evident parenchymal CNS disease-are equally treatable with oral antibiotics, this would appear to be unnecessary [ 25 ]. In endemic areas, the presence of facial palsy, with or without meningitis, with a history of tick exposure is enough to empirically initiate treatment. It is unclear whether steroids help, hinder, or have no effect either way on the recovery of Lyme facial neuropathy [ 50 ]. Treatment responses are comparable between adults and children [ 50 ]. Conclusion The primary manifestation of facial neuropathy is unilateral facial weakness. In the emergent setting, differentiation between facial neuropathy and stroke is most important. Once facial neuropathy is established, the differential is between Bell s palsy, which accounts for most cases, and secondary causes, of which Ramsay Hunt syndrome and Lyme disease are most frequent. If seen within 72 h of onset, patients with Bell s palsy should be treated with at least a 5 day course of relatively high doses of corticosteroids (prednisone 60 mg or prednisolone 50 mg). If their facial neuropathy is severe or complete, a course of antiviral therapy directed against HSV should be considered. If vesicular lesions of the ear or mouth are present, antiviral treatment is essential. In areas endemic for Lyme disease, oral antibiotic treatment should be initiated for patients with a history of tick exposure, even if the Lyme disease ELISA is negative. Imaging and CSF examination should be reserved for those patients with facial neuropathy and high suspicion of other secondary causes, including multiple cranial neuropathies, neurologic signs or symptoms beyond the cranial 141 nerves, fever, meningismus, and the presence of other medical diseases known to be associated with facial neuropathy. References 1. Peiterson E. Bell s Palsy: The Spontaneous Course of 2,500 Peripheral Facial Nerve Palsies of Different Etiologies. Acta Otolaryngol 2002;Suppl 549: Katusic SK, Beard M, Wiederholt WC, Bergstralh EJ, Kurland KT. Incidence, clinical findings, and prognosis in Bell s palsy, Rochester, Minnesota, Ann Neurol. 1986;20: Marson AG, Salinas R. Bell s palsy. West J Med. 2000;173: Keane JR. Bilateral seventh nerve palsy: analysis of 43 cases and review of the literature. Neurology. 1994;44: Hato N, Kisaki H, Honda N, Gyo K, Murakami S, Yanagihara N. Ramsay Hunt Syndrome in children. Ann Neurol. 2000;48: Furuta Y, Ohtani F, Aizawa H, Fukuda S, Kawabata H, Bergstrom T. Varicella-Zoster virus reactivation is an important cause of acute peripheral facial paralysis in children. Pediatr Infect Dis J. 2005;24: Ogita S, Terada K, Niizuma T, Kosaka Y, Kataoka N. Characteristics of facial nerve palsy during childhood in Japan: frequency of varicella zoster virus association. Pediatr Int. 2006;48: Ge XX, Spector GJ. Labyrinthine segment and geniculate ganglion of facial nerve in fetal and adult human temporal bones. Ann Otol Rhinol Laryngol. 1981;90 suppl 85: McCormick DP. Herpes-simplex virus as cause of Bell s palsy. Lancet. 1972;1: Hato N, Murakami S, Gyo K. Steroid and antiviral treatment for Bell s palsy. Lancet. 2008;371: Furuta Y, Fukuda S, Chida E, et al. Reactivation of herpes simplex virus type 1 in patients with Bell s palsy. J Med Virol. 1998;54: Takasu T, Furuta Y, Sato KC, et al. Detection of latent herpes simplex virus DNA and RNA in human geniculate ganglia by the polymerase chain reaction. Acta Otolaryngol. 1992;112: Burgess RC, Micheals L, Bates Jr JF, Smith RJH. Polymerase chain reaction amplification of herpes simplex viral DNA from the geniculate ganglion of a patient with Bell s palsy. Ann Otol Rhinol Laryngol. 1995;104: Murakami S, Mizobuchi M, Nakashiro Y, et al. Bell s palsy and herpes simplex virus: Identification of viral DNA in endoneural fluid and muscle. Ann Intern Med. 1996;124: Sugita T, Murakami S, Yanagihara N, et al. Facial nerve paralysis induced by herpes simplex virus in mice, an animal model of acute and transient facial paralysis. Ann Otol Rhino Laryngol. 1995;104:

10 142 J.M. Gilchrist 16. Hato N, Hitsumoto Y, Honda N, et al. Immunologic aspects of facial nerve paralysis induced by herpes simplex virus infection in mice. Ann Otol Rhinol Laryngol. 1998;107: Takahashi H, Hitsumoto Y, Honda N, et al. Mouse model of Bell s palsy induced by reactivation of herpes simplex virus type 1. J Neuropathol Exp Neurol. 2001;60: Honda N, Hato N, Takahashi H, et al. Pathophysiology of facial nerve paralysis induced by herpes simplex virus type 1 infection. Ann Otol Rhinol Laryngol. 2002;111: Finsterer J. Management of peripheral facial nerve palsy. Eur Arch Otolaryngoscopy. 2008;265: Sweeney CJ, Gilden DH. Ramsay Hunt syndrome. J Neurol Neurosurg Psychiatr. 2001;71: Murakami S, Honda N, Mizobuchi M, et al. Rapid diagnosis of varicella zoster virus infection in acute facial palsy. Neurology. 1998;51: Halperin JJ. Facial nerve palsy associated with Lyme disease. Muscle Nerve. 2003;28: Vanopdenbosch LJ, Verhoeven K, Casselman JW. Bell s palsy with ipsilateral numbness. J Neurol Neurosurg Psychiatr. 2005;76: Devreise PP, Moesker WH. The natural history of facial paralysis in herpes zoster. Clin Otolaryngol. 1988;13: Halperin JJ. Nervous system Lyme disease. Infect Dis Clin North Am. 2008;22: Pachner AR, Steere AC. The triad of neurologic manifestations of Lyme disease. Neurology. 1985;35: Clark JR, Carlson RD, Sasaki CT, et al. Facial paralysis in Lyme disease. Laryngoscope. 1985;95: Kimura J, Rodnitzky RL, Okawara S. Electrophysiologic analysis of aberrant regeneration after facial nerve paralysis. Neurology. 1975;25: Gilliatt RW, Taylor JC. Electrical changes following section of the facial nerve. Proc R Soc Med. 1959;52: Dumitru D, Walsh NE, Porter LD. Electrophysiologic evaluation of the facial nerve in Bell s palsy. Am J Phys Med Rehabil. 1988;67: Kennelly KD. Electrophysiological evaluation of cranial nerves. Neurologist. 2006;12: Engstrom M, Jonsson R, Grindlund M, Stalberg E. Electroneurographic facial muscle pattern in Bell s palsy. Otolaryngol Head Neck Surg. 2000;122: Olsen PZ. Prediction of recovery in Bell s palsy. Acta Neurol Scand. 1975;52 suppl 61: Taverner D. Electrodiagnosis in facial palsy. Arch Otolaryngol. 1965;81: Korzec K, Sobol SM, Kubal W, Mester SJ, Winzelberg G, May M. Gadolinium-enhanced magnetic resonance imaging of the facial nerve in herpes zoster oticus and Bell s palsy: clinical implications. Am J Otol. 1991; 12: Sartoretti-Schefer S, Wichmann W, Valavanis A. Idiopathic, herpetic, and HIV-associated facial nerve palsies: abnormal MR enhancement patterns. Am J Neuroradiol. 1994;15: Engström M, Abdsaleh S, Ahlström H, Johansson L, Stålberg E, Jonsson L. Serial gadolinium-enhanced magnetic resonance imaging and assessment of facial nerve function in Bell s palsy. Otolaryngol Head Neck Surg. 1997;117: Salinas RA, Alvarez G, Ferreira J. Corticosteroids for Bell s palsy (idiopathic facial paralysis). Cochrane Database Syst Rev 2004, Issue Allen D, Dunn L. Aciclovir or valaciclovir for Bell s palsy (idiopathic facial paralysis). Cochrane Database Syst Rev 2004, Issue Hato N, Yamada H, Kohno H, et al. Valacyclovir and prednisolone treatment for bell s palsy: a multicenter, randomized, placebo-controlled study. Otol Neurotol. 2007;28: Sullivan FM, Swan IRC, Donnan PT, et al. Early treatment with prednisolone or acyclovir in Bell s palsy. New Engl J Med. 2007;357: Sullivan F, Swan I, Daly F. Prednisolone or acyclovir in Bell s palsy. New Eng J Med. 2008;358: Engström M, Berg T, Stjernquist-Desatnik A, Axelsson S, Pitkäranta A, Hultcrantz M, Kanerva M, Hanner P, Jonsson L. Prednisolone and valaciclovir in Bell s palsy: a randomised, double-blind, placebo-controlled, multicentre trial. Lancet Neurol. 2008;7: de Almeida JR, Al Khabori M, Guyatt GH, Witterick IJ, Lin VWY, Nedzelski JM, Chen JM. Combined corticosteroid and antiviral treatment for bell palsy. A systematic review and meta-analysis. J Am Med Assoc. 2009;302: He L, Zhou MK, Zhou D, et al. Acupuncture for Bell s palsy. Cochrane Database Syst Rev 2007, Issue Gantz B, Rubinstein JT, Gridley P, Woodworth GG. Surgical management of Bell s palsy. Laryngoscope. 1999;109: Adour KK, Diamond C. Decompression of the facial nerve in Bell s palsy: a historical review. Otolaryngol Head Neck Surg. 1982;90: May M, Klein SR, Taylor FH. Idiopathic (Bell s) facial palsy: natural history defies steroid or surgical treatment. Laryngoscope. 1985;95: Murakami S, Hato N, Horiuchi J, et al. Treatment of Ramsay Hunt syndrome with acyclovir-prednisone: significance of early diagnosis and treatment. Ann Neurol. 1997;41: Halperin JJ, Shapiro ED, Logigian EL, et al. Practice parameter: treatment of nervous system Lyme disease. Neurology. 2007;69: Shapiro E, Gerber M. Lyme disease and facial nerve palsy: more questions than answers. Arch Pediatr Adolesc Med. 1998;152: