see also: [[Cranial nerve palsies]], [[Weakness#unilateral facial weakness ddx|unilateral facial weakness]], [[Herpes zoster#Ramsey Hunt syndrome]] see: [royal eye and ear - seventh cranial nerve palsy](x-devonthink-item://696EB940-EAE2-4936-B202-809CED0CEB76), [Hayes' - Bells palsy](x-devonthink-item://45BFB6B1-0698-4B12-8CE9-B51105E7BB6B) > AKA **CN VII Palsy** DDx: [[Herpes zoster|Ramsey-hunt syndrome|Ramsay Hunt syndrome]], middle ear pathology / [[Mastoiditis]], [[Giant Cell Arteritis|GCA]], parotid gland pathology, trauma, compression of peripheral nerve (eg from vestibular schwannoma or skul base tumour, compression from cholesteatoma or parotid tumour), previous surgery, tick envenomation, stroke, other causes of unilateral facial weakness, myasthena gravis, GBS > [!danger] Red flags that it isn't Bell's palsy > - other neurological features such as severe headache, blurred vision, diplopia, weakness/numbness in arms or extremities, or ataxia (consider stroke!) > - sparing of the forehead movements > - hyeracusis (increased sensitivity to sound and altered taste are uncommon in Bell's palsy in kids (per RCH) but relatively common in adults > - preceding viral infections or trauma to the head or face > - severe pain (may indicate mastoiditis or VZV # Overview - Bell's palsy involves all facial nerve branches on the affected side - ==*ptosis* and *forehead muscle weakness* must be present for a diagnosis of Bell's palsy== - these features are absent in upper motor neuron lesions - this is a **diagnosis of exclusion** **Risk factors** - pregnancy (3x greater risk and in first postpartum week - diabetes **Features** - onset: usually over hours to days - facial pain : usually mild pain in the face or behind the ear - may precede onset of facial paralysis - *rule out mastoiditis* with this symptom! - dry eyes and poor tear clearance from eyes - +/- previous similar episodes - difficulty in closing the affected eye; eye may "roll up" in an attempt to do so ("Bell's sign") - the patient may subjectively feel the affected side of the face is "numb," but ==true loss of facial sensation is not a feature of Bell's Palsy== *general list:* - younger patients - gradual onset over hours-to-days - forehead (frontalis) affected -- cannot raise eyebrows - lower facial muscles affected - inability to close eyelid - drooping corner of mouth / loss of nasolabial fold - dry eyes with excessive lacrimation to compensate - ipsilateral loss of taste - hyperacusis **Exam** - look at eye for corneal abrasions - full neuro exam (cranial and peripheral) is essential - look for skin lesions or vesicles on face or in ear canal ([[Herpes zoster#Ramsey Hunt syndrome|Ramsay Hunt Syndrome]] - check ear, throat, face on ipsilateral side - signs of otitis media, mastoiditis, or parotitis - the tympanic membrane should not be inflamed - presence of infection raises possibility of **complicated otitis media** and vesicles suggests Ramsay Hunt syndrome - limb weakness → it's a [[Stroke]]! - [[Diplopia]] → consider intracranial tumours causing CN III, IV, or VI palsy - deafness, tinnitus, vertigo → consider Ramsay hunt. rarely cerebellopontine angle tumour (eg vestibular schwannoma) - sensory loss → consider CN V lesion - headache, jaw claudication, scalp tenderness, PMR, weight loss → consider [[Giant Cell Arteritis|GCA]] **Complications** - corneal drying with consequent ulceration and infection - loss of taste over anterior 2/3 of tongue - hyperacusis (↑ sensitivity of sound; due to chordae tympanie or nerve to stapedius involvement) - drooling and difficulty eating and speech - incomplete recovery / depression | | Features suggest Bell's | Features suggest alternative Dx | | ------------------ | --------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------- | | onset | hours to 3 days | insidious onset (or immediate) | | pain | mild facial or post-auricular pain | headache or severe facial pain | | neurology | isolated unilateral CN VII palsy (hyperacusis and altered taste commonly occur from chorda tympani involvement) | bilat disease, diplopia, paraesthesia, other weakness, deafness, tinnitus, vertigo | | systemic features? | no | headache, weight loss, night sweats, fever, fatigue, rash | | recovery | starts over first thre weeks | no improvement seen within first 4 weeks | ## House-Brackmann scale for facial nerve | Grade | findings | | ----- | ------------------------------------------------------------------------------------------------------------- | | I | normal symmetrical function | | II | - complete eye closure with minimal effort<br>- slight asymmetry of face noticed on max effort | | III | - complete eye closure<br>- strong but asymmetrical mouth movement<br>- obvious weakness, but not disfiguring | | IV | - *incomplete eye closure*<br>- asymmetry of mouth with max effort | | V | - incomplete eye closure<br>- motion barely perceptible | | VI | no movement detectable and loss of tone | ## CN VII overview ![[Pasted image 20241102214059.png]] - Facial nerve innervates motor fibres that innervate muscles of facial expression - also innervates parasympathetic fibres to lacriminal, submandibular, and sublingular salivary glands - afferent fibres from taste receptors from anterior 2/3 of tongue - somatic afferents from external auditory canal and pinna # Treatment ## adults - prednisolone 1mg/kg/day (max 75mg) oral for 5-10 days, especially if commenced within 72 hours of onset - eye care: glasses or protective eye pad in day. micropore tape/eyepad at night - lubricating eye drops (artificial tears) eg Poly-Tears or Poly-Visc ?antivirals; controversial, definitely give if Ramsay Hunt. consider if <72 hours and any reason to suspect VZV - considered "optional" in Royal Victoria Eye and Ear guideline - valacyclovir 1g TDS for 7 days - aciclovir preferred in pregnancy ## paeds - most children recover without treatment; don't usually need steroids # Follow up - refer to neuro if atypical features, no improvement within first 4 weeks, or incomplete resolution of symptoms by 3 months - ENT review in 4 weeks for more significant disease (House-Brackmann >III) - +/- opthal review if needed due to any corneal issues