cranial nerves and neuro ophthalmology Flashcards
primary and secondary action of superior oblique
depression/intorsion
primary and secondary action of superior rectus
elevation/intorsion
primary and secondary action of inferior oblique
elevation/extorsion
primary and secondary action of inferior rectus
depression/extorsion
Result of sympathetic innervation to eyelid
innervates muller’s muscle and superior tarsal muscles in the upper eyelids, and inferior tarsal muscles in the lower lid.
location of carotid dissection that leads to anhidrosis
beyond carotid bifurcation (because sympathetic fibers travel with the ECA).
first order neuron in Horner’s
posterior hypothalamus to C8-T2 (spincocilliary center of budge)
second order neuron in Horner’s
C8-T2 to sup. cervical ganglion (carotid bifurcation). Note, travel over apex of lung and under subclavian.
3rd order neuron in Horner’s
sup. cervical ganglion along branches of carotid
path of 3rd order synmpathetic neuron to face sweat glands
along ECA
path of 3rd order sympathetic neurons to pupillary muscles and eyelid muscles.
along ICA, through cavernous sinus, with V1 to orbit.
Use of cocaine in a meiotic eye
in a sympathetically denervated eye cocaine will NOT cause pupil dilation in a Horner’s syndrome, confirming the Horner’s. Does not further localize.
Location of lesion in Horner’s if pupil dilates after hydroxyamphetamine.
First or second order neuron.
Location of lesion in Horner’s if pupil DOES NOT dilate after hydroxyamphetamine.
3rd order.
which oculomotor complex subnucleus innervates the contralateral side?
superior rectus subnucleus.
pathway of afferent limb of pupillary light reflex
retinal ganglia-> optic nerve -> chiasm -> optic tract-> ipsilateral pretectal nucleus (note each pretectal nucleus gets info from contralateral visual field) -> Edinger Westfal nucleus.
Pathway of efferent limb of pupillary light reflex.
Edinger Westfal nucleus-> oculomotor nucleus. ->oculomotor n.–> ciliary ganglia -> (postganglionic) pupilary sphincter.
Lesion location in INO if the left eye cannot adduct.
LEFT MLF (lesion is IPSILATERAL to eye with adduction deficit.
Findings in bilateral MLF lesions
bilateral exotropia causing “wall eyed bilateral INO (WEBINO).
Lesion location in one and a half syndrome if right eye has no horizontal movement and left eye only has abduction.
RIGHT abducens nucleus or PPRF AND RIGHT MLF.
suspected location of lesion in Adie’s tonic pupil
parasympathetic post-ganglionic
findings in acute phase of Adie’s tonic pupil
unilateral mydriasis and lack of reaction to light or accommodation, constriction (hypersensitivity) to dilute pilocarpine.
findings in chronic phase of Adie’s tonic pupil.
unilateral meiosis at rest, lack of reaction to light, intact reaction to accommodation.
most likely diagnosis in adult patient with heart disease who has acute onset painless vision loss and nerve head edema.
Anterior ischemic optic neuropathy.
signs of cavernous sinus syndrome
proptosis, blurred vision, deficits in CN III, IV, VI, V1 and V2
5 features of central vertigo
1.absent latency 2. non-fatiguing 3. lasts longer than 1 min 4. not diminished by visual fixation 5.can occur in any direction.
6 features of peripheral vertigo
- latency present 2. fatiguable 3.lasts 1-20 seconds 4. improves with visual fixation 5.usually horizontal but can have torsional component 6. unidirectional.
direction of slow phase of nystagmus in peripheral vertigo
slow phase is towards affected ear.
in what direction does amplitude of nystagmus in peripheral vertigo increase.
when looking towards the unaffected side.
in the ear, what are the otolithic organs
saccule and utricle
what type of motion do the otolithic organs detect
linear and vertical acceleration
what type of motion do the semicircular canals detect.
angular head motion
path of parasympathetic input to glands of eye and nasal mucosa.
sup. salivatory nuc –> nervus intermedius –> geniculate gangion (no synapse) –>greater petrosal n. –> pterygopalatine gangion –>glands
Path of parasympathetic input to the mouth.
sup salivatory nuc–>nervous intermdius–> geniculate ganglion (no synapse) –> chorda tympani –>submandibular gangion –> glands.
first branch of facial nerve after the geniculate ganglion
nerve to stapedius.
path of taste afferents from anterior 2/3 of tongue.
tongue–>chorda tympani–>through ext aud meatus–>geniculate nucleus (synapse) –>nervus intermdius –>tractus solitarius in brainstem.
which brainstem nucleus gives rise to parasympathetic input to the parotid gland via CN IX?
inferior salivatory nucelus.
which foramen does CN IX exit?
jugular foramen.
what is the path of afferents from the posterior 2/3 of the tongue (taste)?
tongue–> glossopharyngeal n. –> superior and inferior ganglia (at level of jugular foramen) –>tractus solitarius.
afferent and efferent path of baro-receptor reflex.
carotid baro-receptors–> CN IX –> nucleus solitarius –>interneuron –> Dorsal nucleus of X –> Vagus –>heart.
afferent and efferent path of gag reflex
pharynx–> CN IX –>superior and inferior glossopharyngeal ganglia–> tractus solitarius–> nucleus ambigus –>CN X–>pharyngeal muscles.
inputs to nucleus solitarius
- taste afferents via CN VII and CN IX 2. sensory from CN IX (pharynx and baroreceptors).
outputs from superior salivatory nucleus
parasympathetic efferents via CN VII.
outputs from inferior salivatory nucleus
parasympathetic efferents via CN IX.
outputs from nucleus ambigus
motor efferents via CN IX, X and XI
direction of tongue deviation if lesion is supranuclear
contralateral
direction of tongue deviation if lesion is hypoglossal
ipsilateral
what motion does accessory nerve activation cause
ipsi head tilt, contra head rotation.
what nerve supplies tactile sensation to anterior 2/3 of tongue?
Trigeminal
what passes through the superior orbital fissure?
CN III, CN IV, CN V1
what foramina does V2 pass through?
foramen rotundum
what foramina does V3 pass through?
Foramen ovale
What passes through the jugular foramina
sigmoid sinus, CN IX, X, XI
what structure does CN XII pass through
hypoglossal canal
what passes through the internal acoustic meatus
CN VII, CN VIII
what causes sudden painless vision loss preceded by transient monocular blindness?
central retinal artery occlusion.
what is the most likely diagnosis in a patient with sudden painless vision loss and jaw claudication.
Giant cell arteritis.
what disorder consists of slowly progressive nonfatiguable ptosis and ophthalmoplegia with onset after age 30?
chronic progressive external ophthalmoplegia (CPEO)- a mitochondrial disorder.
what sort of nystagmus occurs in Chiari malformation?
downbeat- occurs with lesions at the craniocervical junction.
in what disorders does upbeat nystagmus occur?
cerebellar and brainstem lesions, wernike’s encephalopathy
what type of nystagmus is associated with suprasellar masses?
see-saw
what is the most common cause of convergence retraction nystagmus in a newborn?
congenital aqueductal stenosis
what is the most common cause of convergence retraction nystagmus in an older child
pineal tumor
what is the most common cause of convergence retraction nystagmus in someone in their 20’s?
head trauma
what is the most common cause of convergence retraction nystagmus in someone in their 30s?
brainstem vascular malformation
what is the most common cause of convergence retraction nystagmus in their 40’s?
MS
what is the most common cause of convergence retraction nystagmus in someone in their 50’s?
basilar artery stroke
what makes up mollaret’s triangle?
red nucleus, ipsilateral inferior olivary nucleus, contralateral dentate
what is the most frequent muscle involved in grave’s eye disease?
inferior rectus
what nerve is most often affected in ophthalmoplegic migraine?
Oculomotor
what are the main features of ophthalmoplegic migraine?
onset before age 10
history of typical migraine
ophthalmoplegia is ipsi to headache
ophtalmoplegia starts at peak of headache and persists after headache is gone.
what disorder is associated with bilateral subcapsular cataracts?
NFII
