Facial Palsy Flashcards
Where does the facial nerve leave the skull
Via the stylomastoid foramen in close proximity to the parotid gland
Where does the CN VII travel with CN VIII
Through the internal auditory meatus
What is innervated by CN VII
Muscles of facial expression Taste fibres from the anterior two thirds of the tongue Parasympathetic fibres to the salivary glands and stapedius
What kind of lesion causes forehead sparing facial weakness
UMN lesion
Why is their forehead sparing in a UMN lesion causing facial weakness
The muscles of the forehead have dual innervation, from the contralateral and ipsilateral sides
What side of the face is affected in a facial nerve palsy
The contralateral side
What are some causes of bilateral facial nerve weakness
Guillain-Barre Lyme Disease Sarcoidosis Bilateral Bell’s palsy Myasthenia gravis - with ptosis so no Bell’s sign
What is Bell’s Sign
When a patient attempts to close their eyes but are unable to fully and you can see the whites of their eyes as they roll up and out
What muscle closes the eye
Orbicularis oculi
Which nerve innervates the orbicularis oculi muscle
CN VII - facial nerve
What muscle raises the upper eyelid
Levator palpebrae superioris
Which nerve innervates the levator palpebrae superioris
CN III - occulomotor nerve
What are some UMN causes of facial weakness
Stroke Tumour
What are some LMN causes of facial weakness
Lesion at the pons - infarction, demyelination (MS) Cerebellopontine angle tumour Lesions in the facial canal - middle ear infection, Bell’s palsy, fracture of the base of skull Lesions in the geniculate ganglion - Herpes zoster infection Lesion of the peripheral branches of CN VII - mumps, sarcoidosis, trauma
What other signs would you expect to find in a lesion of the pons
Ipsilateral 6th nerve lesion Contralateral pyramidal weakness
What other signs would you to expect to find in a cerebellopontine angle tumour
Facial sensory loss Loss of corneal reflex Hearing loss
What is the definition of Bell’s palsy
Paralysis of the facial nerve where no specific cause can be found (LMN)
75% of all facial palsies are a Bell’s palsy
What medication do you give for Bell’s palsy
- Prednisolone - high dose, provided started in first week
- Aciclovir - 800mg 5x daily for 1 week
- IV in Ramsay Hunt syndrome
- Corneal protection: Eye lubricant and tape if eye can’t be voluntarily closed
What are some causes of Bell’s palsy?
- Idiopathic (>90% cases)
- Structural lesion:
- Brainstem: tumour, stroke, demyelination
- Cerebellopontine angle: Acoustic neuroma
- Middle ear: Infection
- Parotid gland: INfection, tumour, surgery
- Mononeuritis multiplex
How would you investigate a patient with a Bell’s palsy?
- Typical acute Bell’s palsy (develops over 1-2 days): only random glucose required
- Slow progreesive history/other CNs involved/prominent pain:
- Bloods:
- CRP and ESR
- Serum ACE
- Infectious serology: HIV, Lyme
- Auto-antibodies
- Imaging: MRI brain (T2 for idiopathic Bell’s palsy)
- Further:
- LP: mononueritis multiplex or meningeal inflammation
- Nerve conduction studies (GBS)
- Pure tone audiometry
- Bloods:
What are the complications of a Bell’s palsy?
- Persistent facial weakness
- Corneal abrasions
- Pain and/or sensory disturbance in the distribution of the facial nerve
- Aberrant reinnervation: “Crocodile tears” when talking or eating, or jaw-eyelid synkinesia
- Hemifacial spasm
What is the prognosis of a facial nerve palsy?
- Complete palsy: 80% get full recovery
- 20%- delayed recovery or remaining deficit or cosmetic appearance
What is Ramsay-Hunt syndrome?
An acute perifacial neuropathy due to reactivation of VZV in the geniculate ganglion of CNVII
What are the signs and symptoms of Ramsay Hunt syndrome?
- Preceding pain in ear or stiff neck
- Vesicular rash in auditory canal +/- TM, pinna, tongue and hard palate
- No rash = zoster sine herpete
- Ipsilateral facial weakness, ageusia and hyperacusis
- CNVIII affected –> vertigo, tinnitus, deafness
How would you manage Ramsay-Hunt syndrome?
First 72 hours- IV valaciclovir
Prednisolone
What is the prognosis for Ramsay-Hunt syndrome?
- Treated within 72 hours:
- 75% full recovery
- Otherwise rule of 3rds: 1/3rd full recovery, 1/3rd partial, 1/3rd poor
