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When encountering facial paralysis, patients may first consult their general practitioner. As its impact is not only cosmetic but also functional and psychological, facial paralysis needs to be managed with care. We share how you can optimise care for these patients, from evaluation and grading to treatment.
Facial expressions are one of the most
important non-verbal ways we communicate.
Far from being a simple cosmetic issue, facial
paralysis can result in significant functional and
Bell’s palsy is the most common cause of facial
paralysis. While early clinical trials of mRNA
COVID-19 vaccines reported a very small
number of post-vaccine Bell’s palsy cases, later studies found no association between the two.
In fact, according to recent research, the risk of
Bell’s palsy seems to be higher for those who
develop COVID-19 as compared to those who
get the mRNA vaccine.
The top differential causes of facial paralysis include
idiopathic (Bell’s palsy), infectious (e.g., Ramsay Hunt
syndrome) and tumours (central nervous system [CNS]
/ ear / parotid).
1. Bell’s palsy
The minimum diagnostic criteria are acute
onset, ipsilateral lower motor neuron lesion
and absence of other cranial, ear or parotid
pathology. It is thus a diagnosis of exclusion.
It is postulated that herpes simplex virus type
1 (HSV-1) reactivation leads to compression at
the meatal foramen from nerve swelling.
Progression to maximum weakness must occur
within two days (less commonly, up to two
85% of patients start to recover by three weeks,
achieving full recovery by six months without
any specific intervention. The remaining 15% of
patients have permanent diminished function
(post-paralytic syndrome) and experience
muscle weakness with synkinesis. Synkinesis
refers to the unwanted co-contraction of
different facial muscles (e.g., when the patient
smiles, his eye closes involuntarily).
Risk factors include pregnancy and diabetes.
2. Ramsay Hunt syndrome
This is much less common than Bell’s palsy and
is associated with herpes zoster reactivation.
It is thus more common in the elderly and
Symptoms may be more severe and may
include cranial nerve (CN) VIII symptoms of
hearing loss and giddiness. Vesicles may be
seen on the pinna, external auditory canal,
palate or tongue.
The prognosis is worse than Bell's palsy
with 50-70% of patients achieving complete
3. Other infective causes
Bell’s palsy, with its acute presentation, is commonly
misdiagnosed by the layman as a stroke. Patients
thus commonly present to the accident and
emergency department. However, some patients
may consult their general practitioner first.
Evaluation begins with careful history-taking
regarding comorbidities, onset, duration, previous
episodes and associated symptoms (e.g., vertigo,
hearing loss, otalgia and otorrhoea).
Clinical examination should include the cranial
nerves to determine if this is an isolated CN VII
palsy or if there are multiple CN palsies, as well as
to establish if it is an upper or lower motor neuron
lesion. Carry out a complete head and neck examination
of the ear, parotid gland, neck and intraorally.
Finally, grade the severity of the palsy based on the
Primary care treatment consists of the following:
1. Eye care
(the mainstay of treatment for Bell’s palsy)
(in addition to steroids, not alone)
4. Facial neuromuscular retraining
During the period of paralysis, the patient
should avoid excessive/exaggerated facial
movements as these worsen the facial
asymmetry by pulling the face towards the
As muscle movements return, the focus is
on regaining strength while avoiding facial
synkinesis. The patient should separate
movements of the upper face (e.g., eye
closure) from the lower face (e.g., smiling,
They should eat looking forward rather than
downward at the food, or they could end up
with involuntary eye closure during chewing
after they have ‘recovered’. Movements should be gentle and precise and not exaggerated or forceful.
Patients can refer to this video by Queen
Victoria Hospital entitled ‘Management of
Paresis (full programme)’ for initial information
on how facial rehabilitation should be
There is inadequate evidence supporting
acupuncture at present, however patients
are not discouraged from trying it if they
wish to. They are advised to avoid any
form of electrical stimulation (either through
acupuncture needles or over-the-counter
devices) as this may result in spontaneous
tics and muscle contracture in the long run.
The following patients should be referred to an ENT
specialist for workup, as well as the facial nerve
clinic for facial reanimation options:
Central, ear or parotid symptoms or signs are
present, or when you suspect it is more than
Bell’s palsy (atypical presentation) – An MRI
scan and CT scan will be carried out.
Dense palsy and no improvement by three
weeks – An MRI/CT scan may also be carried
out to exclude another facial nerve pathology in
cases with delayed recovery. Severity of paralysis
and late return of function are poor prognostic
factors for Bell’s palsy. Such patients commonly
recover with residual sequelae and early rehabilitation can improve clinical outcomes.
Chronic facial paralysis of any cause
Recovered paralysis with residual sequelae (e.g., synkinesis) – This is easier to correct when
early or mild, hence referral should be initiated if
there is any doubt.
Facial neuromuscular retraining (NMR)
There are 42 individual facial muscles, innervated by
five separate facial nerve branches and capable of
making more than 10,000 expressions.
Non-specific general therapies used for injuries
to other body parts (such as gross strengthening
and electrical stimulation) should not be applied to
The focus is on improving coordination between
muscles as opposed to simply increasing their
strength. Using a tailor-made retraining programme
will induce long-term improvement by the process of
brain plasticity. At Singapore General Hospital (SGH),
our speech therapists are specially trained in facial
NMR and work with all types of facial nerve conditions.
Botulinum toxin injection (BOTOX®) is an important
adjunct in the treatment of facial nerve disorders.
It prevents the release of acetylcholine across the
neuromuscular junction, causing selective paralysis
of involuntarily contracting muscles around the eyes
It relieves muscle tightness and spasms in longstanding
post-paralytic syndrome. It is also a nonsurgical
treatment for conditions such as blepharospasm
and hemifacial spasm.
BOTOX® effects can last four to six months and over
time, injections can be given at a reduced frequency
of one to two years if facial NMR is also carried out.
BOTOX® injections for such medical indications are
affordable and MediSave/insurance claimable.
Surgery for facial palsy
Surgical treatment is aimed at the holistic restoration
of the droopy brow, eye exposure and smile paralysis
and is MediSave/insurance claimable.
Before one year, the facial muscles are still viable
and the connection of new neural input by means of
nerve grafting from the contralateral facial nerve /
ipsilateral masseter nerve can allow dynamic smiling
and eye closure.
In chronic palsy, facial muscles undergo irreversible
atrophy and another muscle (e.g., temporalis muscle
or a slip of latissimus dorsi muscle) can be used for
Ancillary procedures such as brow lifts enable the
restoration of brow position and prevent obstruction
of the visual axis. Lower eyelid tightening procedures
with the addition of a platinum weight into the upper
eyelid can help the eye to close.
Surgery for post-paralytic syndrome
This consists of selective myectomies or neurectomies
of overactive antagonist facial muscles to enable
rebalancing of the smile and eye closure.
The SGH Facial Nerve Clinic run by Dr Wong Manzhi
was launched in 2016. It is conveniently sited within
the ENT Centre on Wednesday mornings, and aims to
provide one-stop clinical care for both subsidised and
We manage patients presenting with all types of
acute and chronic facial nerve conditions, providing
investigations and holistic management of eye, smile
and face issues.
In association with specially-trained speech therapists,
facial neuromuscular retraining is carried out in
addition to medical and surgical treatment.
Dr Wong Manzhi is a Senior Consultant Plastic Surgeon at Singapore General Hospital (SGH). In addition to all facets of reconstructive and aesthetic surgery, she is one of the few doctors in Singapore who have expertise in the sub-specialty management of facial nerve conditions.
She underwent a year-long operating fellowship at Kyorin University Hospital, Japan, which sees the highest number of patients with facial nerve disorders in Japan. Upon her return, she started the Facial Nerve Clinic located within the Ear, Nose and Throat Centre at SGH and a similar clinic in Tan Tock Seng Hospital. She is also a Visiting Consultant at KK Women’s and Children’s Hospital.
GP Appointment Hotline: 6326 6060
GPs can scan visit the website for more information about the department.
HEAD AND NECK;Face