A 49-year-old lady presents to A&E after waking up and noticing the right side of her face is drooping. Work through the case to reach a diagnosis and appropriately manage the patient.
“I woke up this morning and got a huge shock when I looked in my bathroom mirror, one half of my face was drooping! I immediately panicked and called an ambulance!”
History of presenting complaint
Which side did the patient notice the facial weakness on?
At what time did the patient first notice the facial weakness?
Does the patient have normal facial sensation?
Is there any visual disturbance?
Is the patient able to eat/drink/swallow normally?
Is the patient’s speech normal? (e.g. dysarthria, expressive dysphasia, receptive dysphasia)
Does the patient have any weakness or sensory disturbance elsewhere?
Does the patient have any dizziness or balance problems?
Is the patient orientated in time, place and person?
Is there any history of head trauma?
Is there any history of loss of consciousness?
Is there any recent history of illness?
Has the patient ever experienced anything similar in the past?
“The weakness is on the right side of my face, I brushed my teeth before bed the night before and my face was completely normal, then I woke up at 8am this morning and noticed it. The sensation in my face is fine, no numbness or anything. I can still close my eye and blink. My vision seems fine and I can swallow fluids and solids without any issues. My speech also seems ok, I haven’t noticed any slurring or difficulty getting my words out. I’ve got no weakness in my arms or legs and the sensation everywhere is totally fine. I haven’t had any balance trouble or dizziness. I’ve not felt confused at any point and I haven’t experienced any trauma or loss of consciousness. I haven’t had any infections recently and I’ve never experienced anything like this before! Oh, I forgot to mention, something else that’s a bit weird, it feels like everything sound louder, does that make sense?”
Past medical history
Previous similar episodes
History of stroke or transient ischaemic attack
Cardiovascular risk factors:
Other neurological conditions
Antiplatelets or anticoagulants
Other regular medication
Recreational drug use
“I don’t have any medical conditions, I’m usually fit and well. I take a tablet for high cholesterol, oh….so I guess I have high cholesterol, but nothing else. I’ve never taken any recreational drugs and I don’t smoke. There’s no family history of any strokes or any other medical problems.”
The patient is alert and orientated with normal cognition.
There is obvious facial asymmetry on inspection.
The patient is unable to lift her right eyebrow (no forehead sparing).
There is obvious weakness on the right side of the patient’s mouth.
Sensation is normal throughout all areas supplied by the trigeminal nerve bilaterally.
Otoscopy reveals a normal ear canal and tympanic membrane.
Gross testing of hearing reveals hyperacusis of the right ear.
There are no neurological deficits in any of the limbs.
Balance and gait are normal.
Heart sounds are normal. Pulse is regular. There are no carotid bruits.
Bell’s palsy is a form of facial paralysis occurring as a result of facial nerve (VII) dysfunction.¹ The facial nerve is responsible for controlling muscles of facial expression, controlling hearing via the stapedius muscle and providing taste sensation to the anterior two-thirds of the tongue. Lesions of the facial nerve can result in paralysis of facial muscles, increased hearing volume (hyperacusis) and loss of taste. The symptoms of a facial nerve lesion appear on the side of the head the nerve supplies (e.g. left facial nerve lesion will cause left facial paralysis).
Bell’s palsy is the most common mononeuropathy and the most common cause of acute facial nerve paralysis.¹ Often the cause of Bell’s palsy remains unknown and is therefore commonly referred to as “idiopathic Bell’s palsy“. However, it can occur as a result of the herpes simplex virus type 1 or herpes zoster virus, which are reactivated from cranial nerve ganglia causing inflammation within the nerve.² It is a diagnosis of exclusion, so other causes of facial paralysis such as brain tumours and stroke should be ruled out through history, examination and imaging before an official diagnosis of Bell’s palsy is made.
Bell’s palsy involves a lower motor neurone lesion of the facial nerve (VII). The facial nerve is responsible for innervating all muscles of facial expression, therefore a lesion in the nerve causes weakness of the ipsilateral side of the face. However, if the lesion occurs in the brain (e.g. stroke) the upper facial muscles are often spared. This is because the forehead muscles are represented bilaterally in the cortex and hence if one side of the cortex is damaged the other is able to take over allowing the forehead muscles to continue functioning (forehead sparing).
Reassurance and advice
Reassure the patient that the prognosis is good: most people with Bell’s palsy make a full recovery within 3-4 months. 6
Advise the patient that:
It is important to keep the affected eye lubricated. Lubricating eye drops should be used during the day and eye ointment used at night.
If the cornea is exposed after attempting to close the eyes they should seek prompt medical advice.
If they are unable to close the eye at bedtime they should tape it closed using microporous tape.
Wearing sunglasses outside can help protect the eye
If the patient experiences any irritation, pain or changes in vision, they should seek an urgent assessment.
If facial weakness makes eating difficult, advise the use of a straw for liquids and soft diet.
Steroids have the greatest effect if given within 3 days of onset and improve the speed of recovery.³
Usually, a 10-day course is given.
In the past antivirals such as acyclovir were recommended alongside steroids, however, studies have shown they do not significantly improve outcome compared to the use of steroids alone.4
Overall the prognosis for Bell’s palsy is good with a large number of patients recovering entirely (70%). Those with partial facial nerve palsy are much more likely to fully recover function compared to those with complete palsy.5
Patients who do not fully recover may suffer from a number of complications as a result:
Ageusia (loss of sense of taste)
Chronic facial spasm
Incorrect regrowth of nerves causing faulty connections – e.g. patient attempts to close eye but raises the corner of their mouth.
Refer urgently to neurology or ENT surgery if there is:
Any doubt regarding the diagnosis
Recurrent Bell’s palsy
Bilateral Bell’s palsy
If the cornea remains exposed after attempting to close the eyelid, refer urgently to ophthalmology.
If the paralysis shows no sign of improvement after 1 month, or there is suspicion of a serious underlying diagnosis (e.g. cholesteatoma, parotid tumour, malignant otitis externa), refer urgently to ENT.
If there is residual paralysis after 6–9 months, consider referral to a plastic surgeon with a special interest in facial reconstructive surgery. 6