Cranial Nerves Flashcards
What is the cranial nerve exam for Olfactory nerve 1?
Smell
Citrus smells
What is the cranial nerve exam for Optic nerve 2?
Visual activity
Visual field - look at nose
Pupillary reflexes - shine light
What are the possible lesions based on optic nerve testing?
Left optic nerve lesion - left direct lost, right consensual lost
Left oculomotor nerve lesion - left direct and consensual lost
Which nerves are afferent and efferent visual testing?
Afferent - optic nerve
Efferent - oculomotor nerve
What muscles do oculomotor, trochlear, abducens nerve 3, 4, 6 supply?
Extraocular muscles
Oculomotor - recuts, inferior oblique, efferent pupils
Trochlear - superior oblique
Abducens - lateral rectus
What is the cranial nerve exam for oculomotor, trochlear, abducens nerve 3, 4, 6?
Eyelid droop
Ask patient to keep her still and follow finger
Check lateral and vertical
What does oculomotor 3rd nerve palsy look like?
Caused by berry aneurysm, diabetes
Unilateral ptosis
Eye looks down and out
Dilated pupil
Pupil fixed to light
What does trochlear 4th nerve palsy look like?
Double vision
Looking down and in
What does abducens 6th nerve palsy look like?
Double vision
Looking laterally
What are the causes of unilateral ptosis?
Horners syndrome - constricted pupil
3rd nerve lesion
What nerve provides facial sensation and masticatory muscles?
Trigeminal nerve:
Ophthalmic
Maxillary
Mandibular
What are the tests for sensory and motor function of trigeminal nerve 5?
Sensory - light touch
Motor - ask patient to clench, palpate muscles
What are the effects of upper motor neruon lesion of trigeminal?
Affects just the mouth
What are the effects of lower motor neuron lesion of trigeminal?
Affects forehead and mouth
What are the effects of motor lesions of trigeminal nerve?
Wasting of temporalis and masseter
Jaw opening deviates to side of lesion
Jaw reflex
What cranial nerve provides facial movements?
Facial nerve 7
What are the motor and sensory tests for facial nerve 7?
Motor - facial expression, provide submandibular, sublingual salivary glands
Sensory - taste to anterior 2/3 tongue
What are the effects of lower motor neuron lesion of the facial nerve?
Bell’s palsy
Viral
Parotid surgery or tumour
Unilateral facial palsy
Loss of taster anterior 2/3
What are the effects of the upper motor neuron lesion of the facial nerve?
CVA
Unilateral facial palsy
Contra lateral
Forehead is spared - bilateral innervation to forehead
What cranial nerve provides hearing?
Vestibulo chochlear nerve 8
How do you test for vestibulocochlear nerve 8?
Whisper a number in one ear while masking the other
What are some consequences of vestibular dysfunction?
Vertigo
Poor balance
Nystagmus
What cranial nerves controls speech, swallow, palatal movement?
Glossopharyngeal
Vagus
What sensory deos glossopharyngeal nerve 9 provide?
Sensory to tonsil lar fossa
Pharynx
Taste posterior 1/3 of tongue
What are the effects of a glossopharyngeal nerve lesion?
Nasopharyngeal tumour
Depressed gag reflex
What motor function does the vagus nerve provide?
Motor to palate, pharynx, larynx
Check by saying ahhh for palatal movement
What are the effects of 9th or 10th nerve lesion?
Dysarthria - difficulty speaking
How do you test for the accessory nerve 11?
Shoulder shrug against resistance
Rotation of head against resistence
What motor innervation does accessory nerve 11 supply?
Motor to sternocleidomastoid and trapezius
What cranial nerve controls tongue movement?
Hypoglossal
What is indicative of a lower motor neuron lesion of the hypoglossal?
Wasting
Fasciculations
Deviation of tongue to side of lesion
What are the effects of an upper motor neuron lesion in the hypoglossal?
Bilateral
Tongue spasm
Movements slow and limited
What happens in there is cerebellar lesion of the tongue?
Alternating tongue movements
Slow and irregular
What are the causes of Horners syndrome?
Interruption of sympathetic fibres to one eye
Cervical cord
Lung tumour spread
Neck trauma
Malignant lymph nodes
What type of disorder is bulbar palsy?
Lower motor neruon
Could be motor neurone disease, tumour in medulla
Tongue wastes
What type of disorder is pseudobulbar palsy?
Upper motor neuron disorder
Due to bilateral lesions- stroke, MS
Caused by paralysis of lower cranial nerves
Slurred speech, Dysphagia, hoarse voice
Tongue not wasted - slow and stiff movements
