Eye (2004) 18, 1225–1234 & 2004 Nature Publishing Group All rights reserved 0950-222X/04 $30.00 www.nature.com/eye 1 2 3 Ophthalmic V Lee , Z Currie and JRO Collin REVIEW management of facial nerve palsy Abstract The facial nerve travels with the eighth cranial nerve through the internal auditory canal and The ophthalmologist plays a pivotal role in the through the internal fallopian canal in the evaluation and rehabilitation of patients with petrous temporal bone for the longest facial nerve palsy. It is crucial to recognize and interosseus course of any cranial nerve (30 mm). treat the potentially life-threatening The fibres for the pterygopalatine ganglion underlying causes. The immediate ophthalmic leave at the geniculate ganglion as the greater priority is to ensure adequate corneal superficial petrosal nerve. The nerve to the protection. The medium to long-term stapedius and the chorda tympani (innervation management consists of treatment of epiphora, to the salivary glands) leave prior to the nerve hyperkinetic disorders secondary to aberrant exiting through the stylomastoid foramen as a regeneration and poor cosmesis. Patients purely motor nerve to the muscles of facial should be appropriately referred for general expression.2 Within the substance of the parotid 1 facial re-animation. This review aims to Central Eye Service gland, it divides into the five main Central Middlesex Hospital provide a guide to the management of this branchesFthe temporal, zygomatic, buccal, Acton Lane complex condition. Park Royal mandibular, and cervical branches. Facial nerve Eye (2004) 18, 1225–1234. doi:10.1038/sj.eye.6701383 Acton London, UK lesions above the geniculate ganglion classically Published online 16 April 2004 cause more severe ophthalmic symptoms 2Department of because lacrimal secretion and orbicularis Keywords: gold weight; tarsorrhapy; facial Ophthalmology closure are involved. Central lesions cause Royal Hallamshire Hospital reanimation; lagophthalmos; aberrant crocodile tears when regenerating fibres to the Glossop Road regeneration; epiphora Sheffield, UK chorda tympani grow down the lacrimal secretory neural pathway. The causes of seventh Normal facial function plays a critical role in a 3Moorfields Eye Hospital nerve palsy are myriad, but can be broadly person’s physical, psychological, and emotional City Road divided into idiopathic, infectious, traumatic, makeup. Facial disfigurement can affect all London, UK and neoplastic. these components and can result in social and Correspondence: vocational handicap. The American Medical Miss V Lee, MA FRCOphth Association (AMA) Guide to the Evaluation of Consultant Ophthalmic Permanent Impairment assigns a ‘percentage of Causes Surgeon whole person impairment’ percentage of 10–15 Central Eye Service Idiopathic and 30–45%, respectively, to describe the Central Middlesex Hospital Acton Lane impairment imposed by permanent unilateral Bell’s palsy is defined as an idiopathic paresis or Park Royal London NW10 1 and bilateral facial paralysis. paralysis of the facial nerve. It is typically 7NS, UK The Ophthalmologist plays a pivotal role in unilateral, with a sudden onset, and generally Tel: 02084532435 the multi-disciplinary team involved in the spontaneously resolves within 6 months. Many Fax: 02084532404 evaluation and rehabilitation of patients with aetiologies have been proposed, including a E-mail: vickielee@ mac.com facial nerve palsy. viral/inflammatory mechanism3,4 and systemic steroids and/or acyclovir been recommended Received: December 2003 as treatment. However, two population-based Anatomy and aetiology Accepted: 6 November studies from the UK5 and Canada6 have 2003 The facial nerve arises from the facial nucleus in estimated an incidence of 13.1–20.2/100 000. Published online: 16 April the pons and passes laterally at the Both studies found no temporal or geographical 2004 cerebellopontine angle, where it is accompanied clustering to suggest a viral aetiology. The The authors have no by the nervus intermedius (tearing, salivation, current available evidence from the Cochrane financial or proprietary taste), and the nerve to the stapedius muscle. database has shown no significant benefit from interest in this study. Facial nerve palsy V Lee et al 1226 the use of systemic corticosteroids7 or acyclovir8 in Bell’s neuromas found that the rate of anatomical preservation palsy. A compressive, mechanical aetiology has also been was 93%, and that there was an increasing preservation postulated for some cases of Bell’s palsy, as another of the facial nerve due to special eletrophysiological study9 found that idiopathic facial nerve palsy occurred monitoring.19 three to six times more frequently in pregnant patients. Malignant tumours of the external auditory canal can cause proximal facial nerve palsy. Malignant parotid tumours and facial nerve schwannomas may all cause Infection facial nerve palsies. Nasopharyngeal carcinoma may Geniculate ganglionitis (Ramsay Hunt syndrome) caused affect the spheno-palatine ganglion or cavernous sinus by herpes zoster is classically associated with zoster and cause isolated tear deficiency associated with nerve vesicles on the ear, in the external auditory canal or VI palsy. tympanic membrane, with vestibulo-auditory symptoms due to the proximity of the eighth cranial nerve in this Other causes area.10 Lyme disease (Borrelia Burgdorferi) is a known infectious cause of facial palsy, and should be considered Facial diplegia is usually due to supranuclear causes in the differential diagnosis of any patient who has (brainstem contusion, glioma, stroke), and rarely results visited endemic areas.11 Tuberculous otitis media should in the same severity of facial paralysis as infranuclear be considered in the presence of chronic middle ear pathology. Other causes include Moebius syndrome and disease. Facial palsy can be the first presenting sign of myasthenia gravis. AIDS, but is generally described in chronic HIV infection.12 Other infections include polio,13 mumps,14 leprosy,15 cat scratch,16 and dengue fever.17 General evaluation The ophthalmologist must determine the likely aetiology, Traumatic the level of the lesion (proximal/distal), and ensure the treatment of any underlying cause in the acute stages. Both blunt and penetrating cranio-facial trauma may cause facial nerve injuries. High-resolution-computed tomography is used for localization of nerve injury in Facial nerve grading systems suspected cases of temporal bone trauma. In the absence The gold standard for grading facial nerve function is the of gross radiographic abnormalities, electrophysiologic House–Brackmann grading scale.20 Due to the limitations testing helps predict the likelihood of spontaneous and subjectivity of this scale, several new scales21 of recovery. In patients with deteriorating facial nerve various degrees of objectivity and ease of use, including injuries by electroneuronography, surgical exploration is systems incorporating computer analysis22,23 and moire´ the preferred management. Primary end-to-end photography,24 have been introduced. neurorrhaphy is the preferred management for transection injuries, while facial nerve decompression may benefit other forms of high-grade nerve trauma. Ocular complications and treatment Secondary facial reanimation procedures (see later) are Paralysis of the orbicularis oculi muscle has implications useful adjuncts when initial facial nerve repair is for lid closure, with risk of corneal exposure. unsuccessful or impossible.18 Corneal exposure and lagophthalmos Neoplastic Treatment directed at protecting the cornea depends on Total ipsilateral facial weakness, decreased tearing the predicted prognosis of return of nerve function and (nervus intermedius), hyperacusis (nerve to the the degree of risk to the cornea based on the amount of stapedius muscle), and associated defects with V, VI, lagophthalmos and the quality of Bell’s phenomenon and VIII, and Horners syndrome occur classically post the presence or absence of paralytic ectropion. Estimating surgery to tumours in the cerebellopontine angle. These the likelihood of recovery requires good communication include acoustic neuromas, meningioma or a globus between all those involved in the patient’s care. jugulare tumour. Recovery will occur in cases where the nerve has been bruised or stretched during tumour Temporary treatment removal, but is less likely to occur where a large segment of the nerve had to be removed, with or without an Where there is low corneal risk and a good prognosis interpositional nerve graft. A large review of acoustic for recovery, intensive lubricants and taping or padding Eye Facial nerve palsy V Lee et al 1227 the lid overnight will usually suffice. Where frequent drops are required, preservative-free methylcellulose preparations are helpful and bland ointment can be used at night. The degree of lagophthalmos and the amount of lubricants needed may be reduced with temporary lid loading using external eyelid weights.25 Botulinum toxin, injected either transcutaneously through the skin crease or subconjunctivally at the upper border of the tarsus, will produce complete ptosis and afford corneal protection.26 The cornea may, however, Figure 2 Paracentral (pillar) tarsorrhapy. still be at risk, where there is a poor Bell’s phenomenon coupled with marked laxity of the lower lid. This procedure also has the disadvantage of affecting the patient’s vision, and may provide less than adequate protection as the levator function returns. Another means of closure is