Ocular Disease Iii - Basic Neuro

Front 1

What cranial nerves have their nucleus in the midbrain?

Back 1

CN III, IV

Front 2

Rostral refers to?

Back 2

Upper (closer to head)

Front 3

Caudal refers to?

Back 3

Lower (closer to the bottom)

Front 4

3 parts of the brainstem?

Back 4

Midbrain, pons, medulla

Front 5

CN III nucleus location?

Back 5

midbrain

Front 6

CN IV nucleus location?

Back 6

midbrain

Front 7

CN IX nucleus location?

Back 7

medulla

Front 8

CN X nucleus location?

Back 8

medulla

Front 9

CN XI nucleus location?

Back 9

medulla

Front 10

CN XII nucleus location?

Back 10

medulla

Front 11

CN V nucleus location?

Back 11

pons

Front 12

CN VI nucleus location?

Back 12

pons

Front 13

CN VII nucleus location?

Back 13

pons

Front 14

CN VIII nucleus location?

Back 14

pons

Front 15

What structure looks like Mickey Mouse on the MRI?

Back 15

midbrain

Front 16

The midbrain is aka...

Back 16

mesencephalon

Front 17

What structure has the superior and inferior colliculi?

Back 17

Midbrain

Front 18

A lesion of the superior colliculus will affect...

Back 18

saccadic eye movements and eye-head coordination

Front 19

What is the basis pontis?

Back 19

A large bump on the ventral surface of the pons

Front 20

CN nuclei of midbrain?

Back 20

III, IV

Front 21

CN nuclei of pons?

Back 21

V, VI, VII, VIII

Front 22

CN nuclei of medulla?

Back 22

IX, X, XI, XII

Front 23

What is on the dorsal side of the medulla?

Back 23

fourth ventricle and cerebellum

Front 24

What is directly connected caudally to the medulla?

Back 24

spinal cord

Front 25

From superior to inferior, what is the order of the three brainstem structures?

Back 25

midbrain, pons, medulla

Front 26

What is Wallenberg Syndrome?

Back 26

aka Dorsolateral medullary syndrome:
- Ipsilateral horner syndrome (inverse ptosis + miotic pupil)
- Contralateral hypertropia (skew deviation)
- Torsional nystagmus
- Hoarseness, difficulty swallowing (CN IX & X)
- Ataxia (since next to cerebellum)
- Cause = vertebral artery dz

Front 27

What is the MLF?

Back 27

Medial Longitudinal Fasciculus - bundle of fibers controlling vestibular fxn and eye movements; oculomotor, trochlear, and abducens nuclei integrated by MLF

Front 28

What bundle of fibers that run along the brainstem integrate CN III, IV, and VI?

Back 28

MLF

Front 29

What is the riMLF?

Back 29

Rostral Interstitial nucleus of the Medial Longitudinal Fasciculus - for vertical saccades, connects CN III nuclei via posterior commissure

Front 30

What connects CN III to the riMLF?

Back 30

Posterior commissure

Front 31

The MLF extends from ___ to ___.

Back 31

rostral midbrain, rostral medulla

Front 32

This structure lies lateral to the oculomotor nuclei and medial to the abducens nuclei.

Back 32

MLF

Front 33

What nucleus is important for vertical saccadic eye movements?

Back 33

riMLF

Front 34

What structure is important for horizontal eye movements (conjugate gaze and saccadic)?

Back 34

PPRF

Front 35

What is the PPRF?

Back 35

Paramedian Pontine Reticular Formation - area in pons controlling horz conjugate gaze and saccadic eye movements, referred to as Horizontal Gaze Center

Front 36

Outline the cerebrospinal fluid course.

Back 36

Produced in choroid plexus in lateral ventr; lateral ventr, interventr foramina, 3rd ventr, sylvian aqueduct, 4th ventr, 3 foramina, subarachnoid space, arachnoid villi in superior saggital sinus

Front 37

What condition can involve extremely high intracranial pressure then go back to normal?

Back 37

sleep apnea

Front 38

Papilledema is an indication of what potential blockage?

Back 38

cerebrospinal fluid blockage within ventricles

Front 39

What are cisterns?

Back 39

expanded areas within subarachnoid space of brain and spinal cord

Front 40

Where is the lumbar cistern? What is its significance?

Back 40

Between L2 and S2; where spinal taps are performed

Front 41

___ will result in blood in the CSF.

Back 41

Subarachnoid hemorrhage

Front 42

___ will result in pus in the CSF.

Back 42

Meningitis

Front 43

ICP >200-250 mm H2O can result in...

Back 43

papilledema (verify?)

Front 44

T/F - CSF bathes the ON in the subarachnoid space.

Back 44

True

Front 45

What CNs innvervate the adnexa and eye?

Back 45

CN II thru VII

Front 46

What is the origin of CN II?

Back 46

Ganglion cell axons from retina

Front 47

CN II course?

Back 47

ON ganglion cells, muscle cone, optic canal (in lesser wing of sphenoid), optic chiasm, optic tract, LGN in thalamus

Front 48

Visual pathway (start @ LGN)?

Back 48

LGN, optic radiations, superior retinal fibers thru parietal lobe, inf retinal fibers thru temporal lobe (Meyer's Loop), visual cortex in occipital lobe

Remember PITS:
Parietal inf VF (thus sup retina)
Temporal sup VF (thus inf retina)

Front 49

Describe the pupillary fibers of CN II.

Back 49

Before axons terminate in LGN, pupillary fibers exit the optic tract and enter brachium of sup colliculus, synapes in pretectal region of midbrain > intercalated neurons > EW nuclei

Front 50

Iris sphincter is innervated by...

Back 50

CN III

Front 51

Ciliary muscle innervated by...

Back 51

CN III

Front 52

Name the two efferent components of the oculomotor nerve

Back 52

EOMs - somatic
Pupils - efferent

Front 53

Oculomotor and pupillomotor fibers make up the ___ nerve.

Back 53

Oculomotor (CN III)

Front 54

Where are the oculomotor nuclei found?

Back 54

Midbrain at level of superior colliculus, ventral to cerebral aqueduct near midline

Front 55

The oculomotor nuclei are (dorsal/ventral) to the cerebral aqueduct?

Back 55

ventral

Front 56

The oculomotor nuclei are (inferior/superior) and (medial/lateral) to the MLF.

Back 56

superior, medial

Front 57

Which cranial nerve nucleus has subnuclei?

Back 57

Oculomotor nucleus

Front 58

Name the muscle(s) controlled by the lateral subnuclei of CN III

Back 58

IR, IO, MR

Front 59

Name the muscle(s) controlled by the medial subnuclei of CN III

Back 59

contralateral SR

Front 60

Name the muscle(s) controlled by the central subnuclei of CN III

Back 60

Bilateral LPS

Front 61

The oculomotor nuclei are located at the (midbrain/pons/medulla) at the level of the ____.

Back 61

midbrain, superior colliculus

Front 62

Course of oculomotor fibers?

Back 62

Thru red nucleus & exit @ midbrain-pontine junct; lower motor neurons join w/ fibers from EW nucleus to form CN III, thru subarach space, pass by post comm artery, enter superior aspect of cavernous sinus, thru SOF, EOMs

Front 63

T/F - Pupillomotor fibers follow same course as oculomotor fibers

Back 63

True

Front 64

Pupillomotor fibers course?

Back 64

EW nuclei > (same course as oculomotor fibers) > axons terminate at ciliary ganglion (at apex of muscle cone); post-ganglionic fibers > 6-10 short ciliary nerves running b/w choroid and sclera, end at CB and iris sphincter

Front 65

What kind of palsy is described by exotropia and hypotropia with a ptosis and a possible mydriatic pupil?

Back 65

CN III palsy

Front 66

This CN nucleus is unique because it innervates structures contralateral to the side it's on.

Back 66

CN IV

Front 67

Which CN has the longest intracranial course of all the CNs?

Back 67

CN IV

Front 68

Which is the smallest of the CNs?

Back 68

CN IV

Front 69

CN IV fibers decussate and exit the _____ aspect of the brainstem at the _____ junction.

Back 69

dorsal, pons-midbrain

Front 70

A left trochlear nuclear lesion will cause this kind of EOM palsy.

Back 70

RSO (contralateral!)

Front 71

The trochlear nucleus is at the level of the ____ in the (midbrain/pons/medulla).

Back 71

inferior colliculus, midbrain

Front 72

CN IV exits the ____, curves around ____, passes between the ___ and ___ arteries, runs along CN ___, enters _____, goes thru ____ and innervates ____.

Back 72

dorsal brainstem, cerebral peduncle, post cerebral and superior cerebellar arteries, CN III, enters cavernous sinus, thru superior orbital fissure, innervates sup oblique muscle

Front 73

Trochlear nerve actions (3)?

Back 73

Incyclotorsion, depression, abduction

Front 74

Pt presents with diplopia worse at near and in downgaze with a head tilt to the left - you suspect palsy of which CN and what side?

Back 74

right CN IV - trochlear

Remember SOTO - tilt opposite

Front 75

What ventricle is next to CN VI?

Back 75

fourth

Front 76

Axons of CN ___ loop around the abducens nucleus.

Back 76

VII

Front 77

Course of CN VI: (dorsal/ventral) thru potine tegmentum, exits at ____ junction into ____ space, goes over ____ bone, into ____, thru ____, innervates ____.

Back 77

ventrally, ponto-medullary junction (i.e. b/w pons and medulla), into sub-arachnoid space, over petrous temporal bone, into cavernous sinus, thru SOF, innervates LR.

Front 78

Your left esotropic patient complains of horz diplopia worse at far with a head turn to the left - you suspect this CN palsy on what side?

Back 78

Left CN VI (head turn same side as affected muscle)

Front 79

CN V course: Exits [what side?] of the ____, goes into _____ ganglion which is located ____.

Back 79

dorsal-medial side of pons, into trigeminal ganglion on the floor of the middle cranial fossa

Front 80

CN V1 course?

Back 80

(superior branch of trigeminal ganglion) - cavernous sinus, SOF; becomes Nasal, Frontal, Lacrimal nerves.

Front 81

CN V2 course?

Back 81

Trigeminal Ganglion (origin), Foramen rotundum; becomes zygomatic, infraorbital, pterygopalatine, meningeal nerves

Front 82

CN V3 course?

Back 82

Trigeminal Ganglion (origin), foramen ovale; becomes buccal, auriculotemporal, lingulal, inf alveolar, medial pterygoid, masseteric, and deep temporal nerves

Front 83

You poke at your patient's lower lid for fun. What CN is involved here (be specific)?

Back 83

CN V2 (sensory innervation of lower lid)

Remember CN V1 innervates upper lid

Front 84

Ventral CN VII nucleus input?

Back 84

from contralateral motor cortex

Front 85

Ventral CN VII nucleus output?

Back 85

ipsilateral lower facial muscles

Front 86

Dorsal CN VII nucleus input?

Back 86

from ipsilateral and contralateral motor cortex

Front 87

Dorsal CN VII nucleus output?

Back 87

ipsilateral upper facial muscles

Front 88

CN VII lower motor neuron fibers: circle around ___, exit at ____ adjacent to CN ___, both CN ___ and CN ____ pass thru _____ into the _____, then thru [this skull foramen], branch to facial muscles.

Back 88

abducens nuclei, exit pontomedullary jxn adj to CN VIII, both CN VII & VIII pass thru int auditory meatus into facial canal, thru stylomastoid foramen

Front 89

What is the unique feature of the upper motor neuron of CN VII?

Back 89

signals for voluntary movement of facial muscles comes from motor cortex of cerebrum

Front 90

CN VII upper motor neuron fibers: axons travel thru ____ tract, thru ______, end up in ____, _____, and _____.

Back 90

Thru corticobulbar tract, thru internal capsule, end up in ipsilateral dorsal and contralateral ventral + dorsal motor nuclei in pons.

Front 91

CN VII upper motor neuron lesions result in? Why?

Back 91

contralateral lower facial palsy due to bilat innervation of forehead; may have limb paralysis on same side

Front 92

CN VII lower motor neuron lesions result in?

Back 92

Ipsilateral upper and lower facial palsy

Front 93

Your stroke patient is able to raise his forehead on both the right and left sides, but has a half smile with only the left side raised. You suspect a lesion where? Why?

Back 93

Lesion at left motor cortex, resulting in loss of innervation to the right CN VII ventral facial nucleus thus a lower right facial palsy.

Front 94

The left half (both upper and lower) of your patient's face is paretic. You suspect a lesion where?

Back 94

Somewhere along lower motor neuron of CN VII, left side.

Front 95

Cavernous sinus: anterior and medial walls? Posterior wall?

Back 95

ant and medial = sphenoid, post = petrous portion of temporal

Front 96

CNs in the cavernous sinus?

Back 96

CN III, IV, V1, VI

Front 97

T/F - Internal carotid artery is in cavernous sinus?

Back 97

True

Front 98

T/F - Oculosympathetic fibers in cavernous sinus?

Back 98

True

Front 99

What lies between the two cavernous sinuses?

Back 99

Sphenoid sinus and pituitary gland

Front 100

Motor fxn of CN V?

Back 100

Muscles of mastication