facial palsy Flashcards
what does the facial nerve consist of?
-the larger motor component, which supplies all the muscles of facial expression
-the smaller nerves intermedius composed of the sensory portion carrying afferent taste fibres from anterior 2/3 of tongue + the parasympathetic portion carrying fibres to the lacrimal, submaxillary and sublingual glands
describe the facial nerve anatomy
-the pons is where the CN 7 originates
-the facial nerve, nerve intermedius and vestibularcochlear nerves exit the brainstem at the cerebellopontine angle
-they enter the temporal bone via the internal auditory meatus
-as it runs through the IAM, branches are given off
-nerves to lacrimal glands, nerves to the strapedius muscle in the ear, the chord tympani branch
what are the 5 branches of the facial nerve
-temporal - muscles of forehead and eyelids etc
-zygomatic -muscles of the eye
-buccal - raises the corner of the mouth and upper lip for a smile
-mandibular branch produces a simple smile and supplies all the muscles of the chin
-cervical - supplies some of the superficial muscles of the neck
what are examples of viral infections that can cause facial palsy?
-herpes simplex/bells palsy
-herpes zoster
-varicella
-measles
-mumps
what are examples of physical injury causes of facial palsy?
-direct trauma
-skull fracture
-cerebellopontine angle tumour
-parotid gland tumour
-injury @ birth
what are examples of other causes of facial palsy (other than viral infection and physical injury)?
-UMN lesions
-MS
-stroke
-HIV
-dental abscess
-ottis media (inner ear infection)
-pregnancy (due to fluid retention in IAM)
what is neuropraxia?
emporary disruption of nerve conduction due to compression, ischemia, or mild stretch.
-lasts < 6 weeks
-complete recovery will happen
what is axonotmesis?
More severe crush or stretch injury leading to axonal damage but with intact supporting structures (Schwann cells, endoneurium).
-duration of symptoms depends on length of nerve
-regenration begins within 3-8 weeks of injury
what is neurotmesis?
Complete transection or severe injury to the nerve
-axon and connective tissue structures are disrupted, leading to loss of nerve continuity.
-needs surgical repair
what is bells palsy?
sudden, temporary weakness or paralysis of the muscles on one side of the face due to dysfunction of the facial nerve (cranial nerve VII).
-cause is unknown, but usually viral infection
what are the signs and symptoms of bells palsy?
-sudden 72 hour painless unilateral facial muscle dysfunction
-fever
-tinnitus
-mild hearing deficit or hyperacusis (increased sensitivity to hearing)
-altered or absent taste of the anterior 2/3 of tongue
-numbness of ear or face
how is bells palsy managed?
-needs a detailed assessment including subjective history
-exclude other causes eg UMN lesions
-oral steroids within 72 hours of onset
-eye protection
-physiotherapy can prescribe exercise
what is a vestibular schwannoma?
-a benign tumour of the vestibulocochlear nerve, usually at the cerebellopontine angle
what are the symptoms of vestibular schwannoma?
-deafness in 1 ear
-pain behind the ear
-tinnitus
-dizziness
-vertigo like symptoms
when would a surgical intervention be necessary for vestibular schwannoma?
-balance disturbance- ataxia
-trigeminal symptoms
-progressive facial weakness
-scans show increase in size > 2.5-3cm
what kind of functional problems can be seen with facial palsy?
-food or drink falling from mouth
-drooling while eating or drinking
-biting the inside of the cheek
-dryness of the affected eye
-excessive tears
-slurred speech
-difficulty keeping eye open during speaking or drinking
-spasms around the eye
what is the surgical technique for vestibular schwannoma?
- a retrosigmoid craniotomy and excision
how can you test the active range of movement of the facial nerve?
-temporal: raise eyebrows
-zygomatic- gentle eye closure
-buccal - show top teeth
-mandibular - smile
-cervical - show bottom teeth or pucker lips
what are some outcome measures that can be used for facial palsy?
-sunnybrook facial grading scale
-house brackmann score
what does the management for eye care and management?
-lubricating drops and ointments
-give advice re glasses or sunglasses
-consider taping at night, patches or moisture eye chambers
what are examples of exercises for facial palsy + how many sets or reps are recommended?
-eye brow rasies
-gentle eye closure
-closed mouth smile
-open mouth smile
-snarls
-pucker lips
-cheek puff
-whistle
10 reps x1-2 sets, 2-3 times daily
what is synkinesis?
an abnormal movement of muscles of facial expression occurring simultaneously with the voluntary movement of other muscles of facial expression
