Bell’s Palsy

In station 5 you may be asked to assess a patient with a facial droop

HISTORY (3 minutes)

  • Timing questions- since when, sudden/gradual, progression, 1 or both sides, all the time/come and go? Ever happened before?
  • Cranial Nerve 7 questions
    • Taste
    • Ringing in the ear, sensitive to loud sounds, ache behind the ear
    • Pain- face/ear
    • Dry eye and mouth
    • Slurred speech
    • Dribble
  • Neuro questions
    • Weakness arms/legs
    • Sensory loss face/arms/legs
    • Headache, vomiting, seizures, personality change, weight loss, night sweats
    • Tremor, l’hermittes, uhthoffs, dizziness/vertigo
    • Speech
    • Swallow
    • Walking, balance
    • Vision
    • Hearing
  • Other causes:
    • Ear infection
    • Any head injury
    • Diabetes
    • Travel? Eg lymes.

EXAMINE (3 minutes)

  • Raise eyebrows
  • Close eyes tight (Bells phenomenon)
  • Resist eye opening
  • Blow out cheeks
  • Smile and show me your teeth
  • Whistle
  • Look for complications eg. exposure keratopathy
  • Look for evidence of treatment eg. tarsorraphy
  • Examine other CNs- 3,4,6, pupils, visual fields, fundoscopy, 5,8
  • Tone, power, coordination, sensation
  • Look in ear for vesicles, cholesteatoma, otitis media and mouth for vesicles. Check for scars behind the ear or within the hair line.
  • Face- feel parotids
  • Hands- capillary blood glucose fingerprick marks, vasculitic signs

ICE + EXPLANATION (2 minutes)

A suggested explanation is as follows:

“There are lots of reasons for weak face muscles.  The most likely reason is a problem with the facial nerve which supplies the face muscles. The cause of this is often unclear- may be viral. Patients usually make a full recovery in 2 -3 months but can take as long as 6 months and some weakness can remain. I’m going to give you steroids for 10 days: 50mg for 5 days, then 40mg, 30mg, 20mg, 10mg, 5mg then stop.  I’m also going to give you an eye protection patch, eye drops and eye ointment and pain relief.  I’ll give you a leaflet which shows you how to do facial massage.  There is a 1 in 10 chance that it could happen again.

I don’t think this is a stroke or a brain tumour because your forehead muscles are affected and a tumour would cause this to happen slowly rather than suddenly and you don’t have any other symptoms or signs.

I’m going to check your BP, have a proper look in your eyes and ears, do some blood tests to check your sugar levels, cholesterol and to look for inflammation, infections etc

I’ll refer you to a neurologist. Let us know immediately if you develop any further symptoms or signs”



Course of facial nerve: nucleus in the pons, fibres around CN 6, emerges at cerebellopontine angle, enters internal auditory meatus with CN 8, geniculate ganglion, facial canal in petrous temporal bone, parotid gland.

Causes of Cranial Nerve 7 lesion:

  1. Pons                 Stroke/space occupying lesion/demyelination
  2. Base of Skull Infective (lymes, TB etc), infiltrative, vasculitic
  3. Cerebellopontine Angle Acoustic neuroma, meningioma, neurofibroma
  4. Petrous Temporal Bone Bell’s Palsy, Ramsay Hunt ,otitis media, cholesteatoma, tumour
  5. Parotid Tumour, sarcoid, mumps, surgery, lymes disease
  6. Other Mononeuritis multiplex (any cause of this e.g. diabetes)

What is Bells palsy?

Bell’s Palsy is named after Sir Charles Bell who described facial paralysis due to trauma.  It is commonly used to describe an acute peripheral facial palsy of unknown cause. HSV activation is the likely cause of Bell’s palsy in most cases.

M=F, any age. Sudden onset and progressive. Face/retroauricular pain can occur but it is often painless. Hyperacusis (nerve to stapedius), reduced taste anterior 2/3 tongue (chorda tympani), dry eye and mouth (parasympathetic to lacrimal and salivary glands)

Bilateral CN 7 palsies: Myaesthenia Gravis, Myotonic dystrophy, Facio-scapularhumeral dystrophy, Guillain-barre syndrome, Sarcoid, lymes, Motor neuron disease, vasculitis, bilateral Bell’s palsy, bilateral cerebellopontine angle tumour, bilateral pons lesions, bilateral parotid problem

Complications: exposure keratopathy, taste loss, synkinesis, weakness, contracture

If brainstem/other cranial nerve signs/bilateral CN 7/recurrent CN 7 problem/slowly resolving palsy: MRI/CT of brain, temporal bone and parotid gland and screening bloodwork (autoimmune screen, HIV test, blood film/LDH, immunoglobulins, ACE)

If solely lower motor neuron CN 7: BP, glucose, lipids, ESR, FBC. Test for lyme’s disease if indicated.

NB: Sparing of the forehead muscles suggests an upper motor neuron lesion because of bilateral innervation to this area


Written by Dr Sarah Kennedy

Resources used to write this document include those listed in the references section of this webpage and also:’s%20palsy&selectedTitle=2~57