Facial nerve paralysis
1256559
221015119
2008-06-22T17:46:19Z
74.72.32.198
/* Bell's palsy */ Removed vandalism
{{Infobox_Disease
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| ICD9 = {{ICD9|351}}
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| eMedicineSubj = plastic
| eMedicineTopic = 522
| MeshID = D005158
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'''Facial nerve paralysis''' is a common problem that involves the [[paralysis]] of any structures innervated by the [[facial nerve]]. The pathway of the facial nerve is long and relatively convoluted, and so there are a number of causes that may result in facial nerve paralysis. The most common is [[Bell's palsy]], an [[idiopathic]] disease that may only be diagnosed by exclusion.
A thorough [[medical history]] and [[physical examination]] are the first steps in making a diagnosis.
[[Image:Paralisis_facialMOCHE.jpg|thumb|right|175px|[[Moche]] Culture Representation of Facial Paralysis. 300 A.D. [[Larco_Museum|Larco Museum Collection]] [[Lima]], [[Peru]].]]
During the '''physical examination''', a distinction must first be made between paralysis and [[paresis]] (incomplete paralysis). Not surprisingly, paralysis is far more serious and requires immediate treatment. It must also be determined whether the [[forehead]] is involved in the motor defect or not. This is usually accomplished by assessing how well a patient can raise her [[eyebrow]]s. The question is an important one because it helps determine if the lesion is in the [[upper motor neuron]] component of the facial nerve, or in its [[lower motor neuron]] component.
Laboratory investigations include an [[audiogram]], [[nerve conduction study|nerve conduction studies]] ([[Electroneuronography|ENoG]]), [[computed tomography]] (CT) or [[MRI|magnetic resonance]] (MR) imaging.
==Causes==
===Bell's palsy===
[[Bell's palsy]] is the most common cause of acute facial nerve paralysis (>80%). Previously considered [[idiopathic]], it has been recently linked to herpes simplex infection other more severe form of facial palsy called Ramsay-Hunt syndrome is linked to [[herpes zoster]]infection of the facial nerve other less common etiologies are [[Lyme disease]]) polio, TB..
Bell's palsy is an exclusion diagnosis. Some factors that tend to rule out Bell's palsy include:
# Recurrent paralysis
# Slowly progressive paralysis (The onset of Bell's palsy is very sudden)
# Twitching
# Associated symptoms (either [[cochlea]]r or neurologic)
Bell's palsy is believed in the most recent studies to be due to herpes virus. Other proposed etiologies include vascular problems in the inner ear. Treatment include [[steroids]] and antivirals.
===Trauma===
[[Physical trauma]], especially [[fracture]]s of the [[temporal bone]], may also cause acute facial nerve paralysis. Understandably, the likelihood of facial paralysis after trauma depends on the location of the trauma. Most commonly, facial paralysis follows temporal bone fractures, though the likelihood depends on the type of fracture.
''Transverse fractures'' in the horizontal plane present the highest likelihood of facial paralysis (40-50%). Patients may also present with [[hemotympanum]] (blood behind the tympanic membrane), sensory [[deaf]]ness, and [[Dizziness|vertigo]] – the latter two symptoms due to damage to [[vestibulocochlear nerve]] ([[cranial nerve]] VIII) and the inner ear. ''Longitudinal fracture'' in the vertical plane present a lower likelihood of paralysis (20%). Patients may present with [[hematorrhea]] ([[blood]] coming out of the [[external auditory meatus]]), [[tympanic membrane]] tear, fracture of [[external auditory canal]], and [[conductive hearing loss]].
Traumatic injuries can be assessed by [[computed tomography]] (CT) and nerve conduction studies (ENoG). In patients with mild injury, management is the same as with Bell's palsy – protect the [[eye]]s and wait. In patients with severe injury, progress is followed with nerve conduction studies. If nerve conduction studies show a large (>90%) change in nerve conduction, the nerve should be decompressed. The facial paralysis can follow immediately the trauma due to direct damage to the facial nerve, in such cases a surgical treatment may be attempted. In other cases the facial paralysis can occur a long time after the trauma due to oedema and inflammation. In those cases steroids can be a good help.
===Tumours===
A [[tumour]] compressing the facial nerve anywhere along its complex pathway can result in facial paralysis. Common culprits are [[facial neuroma]]s, congenital [[cholesteatoma]]s, [[hemangioma]]s, [[acoustic neuroma]]s, [[parotid gland]] [[neoplasm]]s, or [[metastases]] of other tumours.
Patients with facial nerve paralysis resulting from tumours usually present with a progressive, twitching paralysis, other neurological signs, or a recurrent Bell's palsy-type presentation.
The latter should always be suspicious, as Bell's palsy should not recur. A chronically discharging ear must be treated as a cholesteatoma until proven otherwise; hence, there must be immediate [[surgery|surgical]] exploration.
Computed tomography (CT) or magnetic resonance (MR) imaging should be used to identify the location of the tumour, and it should be managed accordingly.
===''Herpes zoster oticus''===
{{main|Ramsay Hunt syndrome type II}}
[[Herpes zoster oticus]] is essentially a [[herpes zoster]] [[infection]] that affects [[cranial nerve]]s VII ([[facial nerve]]) and VIII ([[vestibulocochlear nerve]]).
Patients present with facial paralysis, ear pain, [[vesicle (biology)|vesicle]]s, [[sensorineural hearing loss]], and [[dizziness|vertigo]].
Management includes [[antiviral]]s and oral [[steroid]]s.
===Acute and chronic ''otitis media''===
''[[Otitis media]]'' is an infection in the middle ear, which can spread to the facial nerve and inflame it, causing compression of the nerve in its canal.
[[Antibiotic]]s are used to control the ''otitis media'', and other options include a wide [[myringotomy]] (an incision in the [[tympanic membrane]]) or decompression if the patient does not improve
Chronic ''otitis media'' usually presents in an ear with chronic discharge ([[otorrhea]]), or hearing loss, with or without ear pain ([[otalgia]]). Once suspected, there should be immediate surgical exploration to determine if a cholesteatoma has formed and must be removed.
===Neurosarcoidosis===
Facial nerve paralysis, sometimes bilateral, is a common manifestation of [[neurosarcoidosis]] ([[sarcoidosis]] of the nervous system), itself a rare condition.
==References==
* [http://www.med.uwo.ca/UME/Diane/Year2Postings2004-2005/Trimester%202/CNS/AcuteFacialParalysisPowerpointDrParnes.ppt Acute facial nerve paralysis] - Powerpoint slides from a lecture presented to second year medical school students at the [http://www.uwo.ca/ University of Western Ontario] by Dr. Lorne Parnes on 19 November 2004. These notes are licensed under the [[FDL]].
* [http://www.med.uwo.ca/UME/Diane/Year2Postings2004-2005/Trimester%202/CNS/AcuteFacialNerveParalysisDrParnes.pdf Acute facial nerve paralysis] - Notes from a lecture presented to second year medical school students at the [http://www.uwo.ca/ University of Western Ontario] by Dr. Lorne Parnes on 19 November 2004. These notes are licensed under the [[FDL]].
{{PNS diseases of the nervous system}}
[[Category:Neurological disorders]]
[[Category:Oral and maxillofacial surgery]]
[[Category:Otolaryngology]]
[[de:Fazialislähmung]]
[[ar:شلل العصب الوجهي]]
[[ca:Paràlisi de Bell]]
[[de:Fazialislähmung]]
[[en:Facial nerve paralysis]]
[[es:Parálisis facial periférica]]
[[fr:Paralysie faciale]]
[[nl:Aangezichtsverlamming van Bell]]
[[no:Facialisparese]]
[[hr:Kljenuti ličnog živca]]
[[fi:Bellin halvaus]]
[[pl:Objaw_Bella]]
[[tr:Yüz felci]]
[[vi:Méo miệng]]