Neuroanatomy Exam Ii Cranial Nerves

Front 1

What is the pneumonic for which cranial nerves are sensory, which are motor, and which are both?

Back 1

Some say marry money but my brother says bad business marrying money

Front 2

Most important CNs for us?

Back 2

I-VIII

Front 3

What is a fascicle?

Back 3

The portion of the cranial nerve from the nucleus until it exits the brainstem.

Front 4

What is an infranuclear disorder?

Back 4

Any damage to a cranial nerve that is below the nucleus, either in the fascicle region or after it exits the brainstem and is a full fledged cranial nerve.

Front 5

Which cranial nerves are not in the brain stem?

Back 5

I (olfactory) and II (optic nerve)

Front 6

What is unique about basal cells of CN I?

Back 6

Basal cells in the basement membrane (epithelium) of the olfactory nerve produce new receptor cells ever 60 days. The only area in the entire CNS that regenerates cells.

Front 7

What is the primary olfactory area?

Back 7

Rhinencephalon (olfactory association area, hypothalamus, thalmus-orbitofronal cortex)

Front 8

What is unique about the olfactory tract of CN I?

Back 8

The only sensory nerve that has PRIMARY SENSORY NEURONS in the epithelium as RECEPTORS.

Front 9

Problems associated with CN I

Back 9

anosmia (difficulty smelling)
ageusia (difficulty tasting)

Front 10

Possible causes for CN I problems

Back 10

Cold, allergy affects receptor
Viral cause affects receptor
Trauma affects primary axon
Neoplasm (tumor or aneurysm) can affect blub or tract.

Front 11

Symptoms of Frontal Lobe Dysfunction

Back 11

Seizures
Mental Changes
Depression or Euphoria
Inappropraite language or behavior
Nonfluent aphasia
Confabulation

Front 12

Optometric Concerns with CN I

Back 12

Optic Nerve Compression
Possible Eye Movement Anomalies
Can get papilledema in one eye and optic atrophy in the other due to neoplasm in this area. Foster-Kenedy papilledema can occur because olfactory is right above the optic nerve. You would want to do a smell test, to determine if more frontal lobe problems are present.

Front 13

CN II

Back 13

Optic Nerve (Visual Pathway)

Front 14

Problems with CN II

Back 14

Decreased Visual Acuity
Decreased Visual Field
Afferent Pupillary Defect

Front 15

Use of neutral density filters for testing for APD

Back 15

Similar to neutralizing phorias with a prism bar only you use a neutral density filter bar, put filters in front of good eye.

Front 16

CN III

Back 16

Oculomotor Nerve

Front 17

What is unique about a palsy of CN III?

Back 17

It presents as the most devastating picture of any EOM palsy.

Front 18

Symptoms of CN III palsy

Back 18

Eye won't go up, down, or in
Ptosis (brow up)
Pupil dilated
Often intorsion

Front 19

Causes of CN III palsy

Back 19

Adults: equal distribution between, idiopathic, trauma, aneurysm, vascular, neoplasms
Kids: 50% congenital, but can be other, assume the worst and test from there.

Front 20

What 2 other things having to do with vision are controlled by CN III?

Back 20

Accommodation and Convergence

Front 21

Does CN III go through cavernous sinus?

Back 21

Yes

Front 22

What are the divisions of CN III and what structures do they innervate?

Back 22

Superior Division: levator and superior rectus
Inferior Division: medial rectus, inferior rectus, inferior oblique.

Front 23

Where are the pupillary fibers located in CN III what is the significance?

Back 23

Anteriorly, this means that pupil function is rarely spared when aneurysm is the cause of a sudden CN III palsy

Front 24

What does aberrant regeneration mean? How does it relate to Cn III?

Back 24

Aberrant regeneration is when nerves grow back incorrectly. Misdirection syndrome. Example, when CNIII nerve fibers are damaged and the IR fibers regrow to the levator.

Front 25

What are the chemicals involved in regeneration?

Back 25

Netrins, attractants, and repellants attract and repel growing nerves.

Front 26

What should you think of first if you see lid-gaze dyskinesis (an abnormal amount of lid movement when looking left and right)?

Back 26

Aberrant Regeneration

Front 27

Causes of aberrant regeneration?

Back 27

Congenital
Trauma
Neoplasm
Aneurysm
SCARY- Neurologic emergency - Act quickly!

Front 28

How can an aneurysm damage fibers?

Back 28

It can either put pressure on surrounding structures or it can burst and take nutrients from surrounding tissues.

Front 29

What is the difference between diabetic CN III problems and compressive CN III problems?

Back 29

Diabetics don't usually show signs of aberrant regeneration and pupils aren't involved. If you see a diabetic patient WITH aberrant regeneration and pupil invovlement it probably isn't the diabetes and you should act as if it's a neoplasm or aneurysm.

Front 30

Optometric concerns with CN III

Back 30

Efferent Anomalies
Many EOMs affected
Diplopia
Torsion possible

Front 31

CN IV

Back 31

Trochlear Nerve

Front 32

Causes of CN IV Palsy

Back 32

Most commonly it's congenital or trauma

Front 33

What happens with CN IV palsy

Back 33

superior oblique palsy

Front 34

Symptoms of CN IV palsy

Back 34

-diplopia in down gaze an don horizontal direction
-head tilt
-large vertical fusion amplitudes
-history of intermittent diplopia when tired

Front 35

Where is the nucleus of CN IV?

Back 35

In dorsal midbrain atop MLF, below periaqueductal gray matter at the level of the inferior colliculi.

Front 36

Pathway of CN IV?

Back 36

Fascicle travels dorsally from nucleus, a small portion is in the brainstem, it decussates in the anterior medullary vellum and controls the contralateral superior oblique.

Front 37

What is unique about CN IV and what is the significance?

Back 37

It is the longest CN and this makes it more susceptible to trauma.

Front 38

In what order are cranial nerves affected by aneurysm?

Back 38

CN III is BY FAR the MOST affected by aneurysm. Then CN IV and then CN VI.

Front 39

The 2 most common causes of CN IV palsy?

Back 39

Congenital and Trauma

Front 40

One weird cause for CN IV problems?

Back 40

Ear-Nose-Throat surgery sometimes causes damage to the trochlear pulley (nicks it)

Front 41

Why would you review old photographs when you suspect a congenital CN IV palsy?

Back 41

Because you will often see head tilt in all pictures, these people can't tell that their heads are tilted, everything looks perfectly upright.

Front 42

Optometric Concerns with CN IV

Back 42

Vertical Diplopia
Torsion
Head Tilt

Front 43

CN V

Back 43

Trigeminal Nerve

Front 44

What kind of nerve fibers are in CN V?

Back 44

Motor and Sensory (somatic)

Front 45

Where is the motor nucleus of CN V? Where is the sensory nucleus?

Back 45

Motor: Pons
Sensory: It's long and it extends from the pons through the medulla and into the spine.

Front 46

What are the divisions of the trigeminal nerve? Which divisions go through the cavernous sinus?

Back 46

Ophthalmic*, Maxillary*, Mandibular.
*cavernous sinus

Front 47

Three major branches of ophthalmic division of CN V

Back 47

Frontal Nerve: medial upper lid and medial forehead
Lacrimal Nerve: lacrimal gland, lateral upper lid, and conj
Nasociliary Nerve: medial lid, side of nose, ethmoid, ciliary nerves, afferent corneal reflex

Front 48

How do you test the corneal reflex? Which nerve are we testing?

Back 48

Have patient look up
Bring floss to touch lower cornea
Switch ends for each eye
They should blink (CN V goes back to VII nerve which causes lid to blink)

Front 49

What is Trigeminal Neuralgia?

Back 49

Tic Douloureux
Severe, sharp, stabbing pain
Worst possible
Often triggered by specific stimuli
Pain lasts less than 2 minutes

Front 50

Oragnization of CN V nerve receptors rostral to caudal

Back 50

proprioception
light touch
pain (deepest)

Front 51

Optometric concerns with CN V

Back 51

Afferent portion of corneal blink response.

Front 52

CN VI

Back 52

Abducens Nerve

Front 53

CN VI Nuclei?

Back 53

Paired nuclei at level of pons and 4th ventricle

Front 54

What are the 2 types of neurons contained in the CN VI nuclei?

Back 54

ipsilateral to LR
contralateral through medial longitudinal fasciculus to medial rectus.

Front 55

What kind of palsy is most common cause of strabismus

Back 55

CN VI

Front 56

Where is CN VI most susceptible to trauma and inflammation?

Back 56

Where is crosses the petrous bone

Front 57

Optometric concerns with CN VI

Back 57

Horizontal diplopia
Esotropia (CN VI Palsy)
Common post stroke, trauma

Front 58

Causes of CN VI Palsy

Back 58

Adults and Kids
Neoplasms, Trauma
Idiopathic

Front 59

CN VII

Back 59

Facial Nerve

Front 60

What is unique about CN VII

Back 60

It is the most frequently paralyzed