cranial nerve details

Question 1

where does CN I terminate?

Answer 1

it is a CNS tract that terminates in the olfactory bulb

Question 2

what are true olfactory nerves?

Answer 2

2nd order ganglion nerve cells which pierce the cribiform plate

Question 3

what is a perversion of smell?

Answer 3

parosmia

Question 4

what is an abnormally disagreeable smell?

Answer 4

cacosmia

Question 5

describe the pathway of the neurons of CN I

Answer 5

primary- unmyelinated; through cribiform plate to olfactory bulb
secondary- myelinated bipolar cells; form olfactory tract and terminate in primary olfactory cortex
tertiary- from primary olfactory cortex to entorhinal cortex (area 28), lateral preoptic, amygdaloid body, medial forebrain

Question 6

what are the peripheral connections of CN II?

Answer 6

1st order- rods and cones of retina- connect with bipolar cells
2nd order- retinal bipolar cells synapse with ganglion cells near retina surface
3rd order- ganglion cells; myelinated and form optic nerve fibers
4th order- geniculocalcarine tract from lateral geniculate bodies; pass to occipital cortex

Question 7

what part of the optic radiation curves around the inferior horn of the lateral ventricle?

Answer 7

Meyer’s loop

Question 8

where does the optic tract pass to?

Answer 8

lateral geniculate bodies
superior colliculi
pretectal region

Question 9

how does the optic nerve connect to the Edinger-Westphal nucleus?

Answer 9

posterior commissure

Question 10

how does the optic nerve connect to the other cranial and spinal nuclei?

Answer 10

from superior colliculi via tectobulbar and tectospinal tracts

Question 11

how does the optic nerve connect to other cortical and subcortical areas?

Answer 11

from the occipital cortex

Question 12

which fibers are responsible for simple and consensual light reflexes?

Answer 12

fibers from pretectal region

Question 13

which tract is responsible for visual perception?

Answer 13

geniculocalcarine tract

Question 14

what area is concerned with light reflex?

Answer 14

pretectal area

Question 15

what area is responsible for reflex movements of the eye?

Answer 15

superior colliculus

Question 16

the tectobulbar and tectospinal tracts carry information to?

Answer 16

1. cranial and spinal nuclei for involuntary reflexes (accommodation)
2. pontine nuclei via corticopontine tract for postural reflexes

Question 17

what is the retinal area for central vision?

Answer 17

macula

Question 18

where is vision sharpest and color discrimination best?

Answer 18

fovea centralis

Question 19

what are the cones responsible for?

Answer 19

sharp vision and color discrimination

Question 20

what involves the optic nerve or tract, MC cause is MS?

Answer 20

retrobulbar neuritis

Question 21

what includes various forms of retinitis?

Answer 21

optic or bulbar neuritis

simple, proteinuric, syphilitc, diabetic, hemorrhagic, hereditary

Question 22

what is associated with decreased visual acuity and change in color of optic disc?

Answer 22

optic atrophy

Question 23

what involves the optic nerve but doesn’t produce papilledema?

Answer 23

primary optic atrophy- may be d/t tabes dorsalis, MS, or hereditary

Question 24

what is the sequel to papilledema?

Answer 24

secondary optic atrophy- may be d/t neuritis, glaucoma or increased intracranial pressure

Question 25

what are the syndromes that involve the optic apparatus?

Answer 25

foster kennedy amaurotic familial idiocy (tay- sachs) argyll robertson pupil holmes-adie

Question 26

what may be caused by tumors at the base of the frontal lobe and what are its characteristic symptoms?

Answer 26

Foster-Kennedy ipsilateral blindness and anosmia (atrophy of CN I and II) contralateral papilledema

Question 27

what syndrome is cerebromacular degeneration with severe mental deficiency and what is it associated with?

Answer 27

amaurotic familial idiocy (tay-sachs) | blindness, optic atrophy, dark cherry red macula

Question 28

what reacts only to accommodation is pathologic in tabes dorsalis and also a diabetic complication?

Answer 28

argyll robertson pupil

Question 29

what is characterized by tonic pupil reaction (myotonic pupil) and absence of one or more tendon reflexes?

Answer 29

Holmes-adie syndrome

Question 30

what is an inward sinking of the eyeball d/t sympathetic paralysis of small muscle of muller?

Answer 30

enopthalmos

Question 31

ptosis associated with Horner's syndrome is due to paralysis of what muscle?

Answer 31

superior tarsal

Question 32

what are the 3 components of accommodation and what nerve is being tested?

Answer 32

convergence pupilloconstriction lens thickening CN III or higher

Question 33

what is the Marcus Gunn phenomenon?

Answer 33

pupillodilation with light introduction

Question 34

what does the swinging light test tell you if the test is positive?

Answer 34

retinal or CN II lesion with the sensory arc decreasing the amount of pupillary motor response

Question 35

red reflex that is partially or completely blocked indicates

Answer 35

``` disease of translucent structures of eyes: cornea lens vitreous retinal pigment ```

Question 36

what are the findings typically seen with papilledema?

Answer 36

blurred nerve fibers and cup tortuous, engorged veins and loss of venous pulsations at disc margin obliteration of cup disc elevation and edema

Question 37

what is seen in 5% of population, usually blond caucasians that is hereditary and benign?

Answer 37

pseudopapilledema

Question 38

inflammation of the optic nerve

Answer 38

optic neuritis

Question 39

inflammation of the optic disc

Answer 39

papillitis

Question 40

if inflammation is behind the optic disc and the fundus looks normal but the patient reports vision loss we would assume?

Answer 40

acute retrobulbar neuritis

Question 41

what are 2 eye signs of arteriosclerosis?

Answer 41

venous engorgement distal to arterial crossing | light reflection off the artery- silver wiring

Question 42

what are a collection of degenerative deposits that often appear in the fundus of elderly but don't have clinical significance

Answer 42

drusen bodies

Question 43

where do the 3 peripheral sensory divisions of trigeminal have their nuclei?

Answer 43

gasserian (semilunar) ganglion

Question 44

what is the cutaneous area over the angle of the jaw supplied by?

Answer 44

great auricular nerve of cervicoplexus (C2,C3)

Question 45

the mandibular branch of trigeminal has a recurrent or meningeal branch that innervates what? this explains its association with head pain

Answer 45

dura of middle and anterior cranial fossa

Question 46

what do the lateral pterygoids do?

Answer 46

right- move jaw tip to left | left- move jaw tip to right

Question 47

when the ophthalmic division trigeminal is involved in a lesion what happens?

Answer 47

neuroparalytic keratitis- corneal inflammation and ulceration

Question 48

what disorder is idiopathic, with sharp painful sensation in the 3 branches of trigeminal and what are the AKAs?

Answer 48

trigeminal neuralgia tic douloureux, fothergill's neuralgia

Question 49

what lesion results in paralysis and denervation atrophy of mastication muscles?

Answer 49

LMN lesion of CN V anywhere from pontine nucleus to peripheral cranial nerve

Question 50

what is a line of communication with the opposite cerebellum to allow for the coordination of planned motor functions

Answer 50

corticopontine fibers

Question 51

what carries the sensory arc of the corneal reflex and where does it synapse?

Answer 51

CN V carries and synapses of CN VII motor nuclei causing eye to blink

Question 52

the corneal blink reflex may be absent in the early stages of?

Answer 52

MS

Question 53

what are the divisions of CN VII in the parotid gland?

Answer 53

temporal zygomatic upper buccal

Question 54

what are the cervicofacial divisions of CN VII?

Answer 54

lower buccal mandibular cervical branches

Question 55

what CN innervates the stapedius muscle?

Answer 55

CN VII

Question 56

what supplies parasympathetic secretory and vasodilator impulses to the submaxillary, sublingual salivary and lacrimal glands as well as mucus membranes of mouth and tongue?

Answer 56

chorda tympani- branch of facial nerve

Question 57

what is prosopoplegia?

Answer 57

peripheral facial paralysis

Question 58

where is the lesion located in Bell's palsy?

Answer 58

lateral to geniculate ganglion

Question 59

what are the common factors of peripheral CN VII paralysis?

Answer 59

``` flaccid paralysis (LMN) ipsilateral facial muscles distal to lesion site ```

Question 60

what differentiates stroke from Bell's palsy?

Answer 60

stroke is central type paralysis- forehead is spared, eyes partially involved, neck and mouth fully involved

Question 61

peripheral lesions in CN VII must be where to affect taste?

Answer 61

proximal to stylomastoid foramen

Question 62

complete hemifacial paralysis without loss of taste on ipsilateral 2/3 tongue indicates what?

Answer 62

Bell's palsy

Question 63

the vestibular division of CN VIII is connected to what other nerves for coordinating movement of eyes, head and neck in response to stimulation of semicircular canals?

Answer 63

CN III, IV, VI

Question 64

a "short circuit" or abnormal impulse from what areas can result in nystagmus?

Answer 64

CN III, CN IV, VI and vestibular division of CN VIII

Question 65

what can be the cause of hyperacusis?

Answer 65

CN VII- stapedius muscle or | centrally located problem

Question 66

what is the term for visual perception of to and fro movements often accompanying nystagmus?

Answer 66

oscillopia- vestibular disease symptom

Question 67

a loud noise from out of sight should cause patient to blink. what is the test and reflex?

Answer 67

malingering test | auditopalpebral reflex

Question 68

CN IX motor fibers innervate what?

Answer 68

stylopharyngeus muscle- elevate larynx, pharynx soft palate

Question 69

what area controls reflex of pupil and lens?

Answer 69

pretectum

Question 70

what area controls head and eye movements?

Answer 70

superior colliculus