Disorders of Cranial Nerves Flashcards
which nerve constricts the pupil and by what muscle
occulomotor by constrictor pupillae (circular one)
4 reflexes of cranial nerves
pupillary reflex, corneal reflex, jaw jerk, gag reflex
cranial nerve nuclei of the midbrain
III and IV
cranial nerve nuclei of the pons
V, VI and VII
cranial nerve nuclei of the medulla
IX, X, XI and XII
which cranial nerve has its nuclei in the pontomedullary junction
VIII
what causes optic neuritis
demyelination of the optic nerve (common in MS)
features of optic neuritis
unilateral, reduced acuity, loss of saturation, pain on movement
sympathetic/parasympathetic dilates the pupil
sympathetic
causes of dilated pupil
youth, darkness, anxiety, excitement, mydriatic eye drops, amphetamine, cocaine overdose, 3rd nerve palsy, drain death
causes of a constricted pupil
old age, brightness, miotuc eye drops, opiate overdose, horner’s syndrome
which nerve is responsible for ptosis
occulomotor
in compressive third nerve palsy caused by raised ICP or a posterior artery aneurysm the pupil is spared/affected
affected - it is also painful
causes of an isolated 6th nerve palsy
idiopathic
diabetes
meningitis
raised ICP
true/false cerebellar disease can cause nystagmus
true
causes of nystagmus
congenital visual impairment central vestibular/brainstem disease cerebellar disease peripheral vestibular problem toxins such as alcohol
what is neuralgia
severe pain following the course of a nerve, burning or stabbing
what is trigeminal neuralgia
pain in trigeminal sensory areas often from a trigger
what is trigeminal neuralgia most commonly caused by
a loop of artery or vein in the posterior fossa compressing the 5th nerve
medical treatment of trigeminal neuralgia
carbamazepine (relieves pain)
when would surgery be neccessary in trigeminal neuralgia
when it is being mediciation resistant
what often precedes facial nerve (Bell’s) palsy
pain behind the ear
bell’s palsy is upper/lower motor neuron
low motor neuron
treatment of bell’s palsy
steroids
UMN of facial nerve causing facial paralysis
stroke or a tumour
where is the LMN of the facial nerve
starts in facial nerve nucleus in pons
difference between facial paralysis from stroke vs bell’s palsy
stroke usually spares the forehead
what is vestibular neuronitis
sudden onset of disabling vertigo and n+v
what is thought to cause vestibular neuronitis
a latent infection of herpes simplex virus in vestibular ganglion
what is dysarthria
unclear speech and slurring
what is dysphagia
difficulty swallowing
what conditions do dysphagia and dysarthria occur in
bulbar and pseudobulbar palsy
where is the problem in bulbar palsy
LMN lesion bilaterally of nerves IX, X, XI and XII
what diseases cause bulbar palsy
MND, polio, tumours, sphyilis
where is the problem in pseudobulbar palsy
UMN lesion bilaterally, such as in the internal capsules
condition that can give a brisk jaw reflex and gag reflex
pseudobulbar palsy
condition where you would see a spastic immobile tongue
pseudobulbar palsy
condition where you would see a wasting fasciculating tongue
bulbar palsy
