46 CLINICAL FOCUS ausdoc . com . au
11 OCTOBER 2024
46 CLINICAL FOCUS ausdoc . com . au
Therapy Update
Hitting a nerve : Facial palsy
ENT
Associate Professor Catherine Meller is an otolaryngologist , facial nerve and facial reconstructive surgeon , and director of the facial nerve clinic at the Prince of Wales Hospital , Randwick , Sydney .
A comprehensive approach ranging from medication to rehabilitation is needed to manage this common but challenging condition .
NEED TO KNOW
Early , evidence-based treatment of facial palsy with corticosteroids (+/ - antivirals ), ocular care and referral to facial physiotherapy maximises functional outcomes .
Patients with chronic flaccidity benefit from early surgical intervention to reanimate the native musculature
Patients with incomplete recovery and synkinesis benefit from physiotherapy and chemodenervation as first-line treatment ( and qualify for PBSsubsidised botulinum toxin treatment ).
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FACIAL palsy is a relatively common condition that can affect individuals of all ages . It presents as weakness or paralysis of the facial muscles , resulting in drooping or asymmetrical appearance of the face . While most cases of facial palsy resolve spontaneously , a significant proportion do not , and those patients go on to experience significant social and physical sequelae of facial disfigurement . 1 This article aims to provide GPs with an overview of the current strategies for the evaluation , diagnosis and treatment of facial palsy .
Aetiology and presentation
Facial palsy can have various aetiologies , including viral infections ( such as HSV ), trauma , tumours , and idiopathic causes ( Bell ’ s palsy ). Patients typically present with sudden onset hemifacial weakness , which may progress over hours to days . Additional symptoms may include loss of taste , altered tear production , hyperacusis , and facial , ear or jaw pain . 2 , 3 A thorough history and physical examination may determine the likely site and cause of the facial palsy .
Diagnosis
Approximately 70 % of all facial nerve palsies are considered idiopathic , thus labelled Bell ’ s palsy . 3 , 4 A comprehensive clinical assessment should seek to confirm this diagnosis , by excluding neurologic , otologic , oncologic , vascular , neoplastic , inflammatory or infectious causes for a patient ’ s symptoms , summarised in box 1 . 5
Clinical assessment
A careful history of the onset and progression of paralysis is important . Gradual
Box 1 . Causes of facial paralysis
Neurologic — Stroke — Guillain-Barre syndrome — Multiple sclerosis
Otologic — Otitis media , acute or chronic — Malignant otitis externa — Cholesteatoma — Facial nerve schwannoma
Oncologic — Cerebral tumour — Skin cancer — Parotid tumour — Metastatic disease — Lymphoma
Vascular — Microvascular disease , such as diabetes onset of more than two weeks ’ duration is strongly suggestive of a mass lesion . Medical history should include recent rashes , arthralgias , or fevers , history of peripheral nerve palsy , and exposure to vaccines or new medications .
The physical examination should include careful inspection of the ear canal , tympanic membrane , and oropharynx , as well as evaluation of peripheral nerve function in the extremities and palpation of the parotid gland and neck . Evaluation of cranial nerve function , including all facial muscles , is warranted . 6
Investigation
Serological tests can help identify viral triggers , such as HSV , and autoimmune causes in patients with recurrent or bilateral facial palsy , such as sarcoidosis .
For patients with evidence of infection of the external auditory canal , a viral PCR test may identify herpes zoster . 7
Imaging ( eg , MRI or CT ) may be necessary to rule out structural causes like tumours or vascular abnormalities . 8
Management of acute facial palsy
Symptomatic relief Prescribe ocular lubricants and ointments to prevent corneal exposure . The author recommends preservative-free products and protective eyewear .
Analgesia may be necessary for patients with periauricular pain , which may be severe in those with Ramsay Hunt syndrome and concomitant blistering of the canal .
Medications There is significant benefit from treating Bell ’ s palsy with corticosteroids . 9 Oral corticosteroids ( such as prednisone ) are recommended within 72 hours of symptom
Imaging ( eg , MRI or CT ) may be necessary to rule out structural causes like tumours or vascular abnormalities .
Inflammatory — Sarcoidosis
Infectious — Encephalitis / meningitis — HSV — Herpes zoster virus ( Ramsay Hunt syndrome ) — Epstein-Barr virus — Lyme disease
Trauma — Temporal bone fracture — Iatrogenic injury to the facial nerve
Cerebellopontine angle — Acoustic neuroma — Meningioma
Idiopathic — Bell ’ s palsy onset for Bell ’ s palsy . The best available evidence supports an oral corticosteroid regimen ( prednisone , 50-60mg per day for five days followed by a five-day taper ) as the first-line treatment for Bell ’ s palsy . 9 , 10
Antiviral medications may be considered in cases with suspected HSV involvement . Combination therapy with an oral corticosteroid and antiviral may reduce rates of synkinesis , where misdirected regrowth of facial nerve fibres manifests as involuntary co-contraction of certain facial muscles . Recommended antivirals include valacyclovir ( 1g three times per day for seven days ) or acyclovir ( 400mg five times per day for 10 days ). Treatment with antivirals alone is ineffective and not recommended . 11-13
Children have higher rates of spontaneous recovery than adults , and there is limited compelling evidence for corticosteroid use in children . 14 Nevertheless , corticosteroids may be considered based on case severity and side effect profile .
In pregnant patients , historical concerns about corticosteroid use presenting a risk to the fetus are not supported by recent data . 15 , 16 Pregnant patients should be offered timely , standard corticosteroid therapy , along with individualised advice that takes into consideration any comorbidities , including diabetes , hypertension or mental illness . 17
Surgical interventions Surgical options in the acute period are reserved for refractory , severe , traumatic or recurrent cases where nerve testing shows greater than 92-94 % degeneration and may include facial nerve decompression . 9
Supportive care Psychosocial support and counselling can help patients cope with the emotional impact of facial palsy . Options include formal psychology , online support groups and the provision of education and written patient information from reputable sources .
Rehabilitation and follow-up Rehabilitation helps patients regain muscle strength and function . Early referral to expert facial physiotherapists can help with eye closure ( stretching and taping techniques ). There is evidence in support of physiotherapy in improving facial symmetry , especially in those who do not completely recover , or show signs of synkinesis . 18
Urgent referral to an otolaryngologist , or specialist in facial nerve disorders , is warranted for patients in whom the facial muscles remain acutely and totally flaccid despite maximal medical therapy at 14-21 days post-onset of palsy , or whose hearing and balance are also affected .
Complications and prognosis
Complications of facial palsy can include synkinesis ( involuntary muscle movements ), contractures , and persistent facial weakness . The prognosis varies depending
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