Visual System

Front 1

Ganglion cells that coalesce at the optic nerve, pass through the optic chiasm to optic tracts, synapse at _________

Back 1

Lateral geniculate nucleus of thalamus.

Front 2

Neurons originating in the Lateral geniculate nucleus of thalamus extend through the optic radiations to synapse in ______

Back 2

occipital cortex

Front 3

vision loss or weakness that occurs without an apparent lesion affecting the eye

Back 3

amaurosis

Front 4

swelling of the optic nerve head from any cause—a descriptive term

Back 4

Optic disc edema

Front 5

swelling (edema) of the optic nerve due to increased intracranial pressure (ICP)

Back 5

papilledema

Front 6

papilledema: pathophys

Back 6

obstruction of axoplasmic flow within the optic nerve

Front 7

T/F Papilledema is often bilateral

Back 7

T. (With rare exceptions)

Front 8

T/F Pupils are usually normal in papilledema

Back 8

T

Front 9

central scotoma : defn

Back 9

Area of decreased vision in the visual field surrounded by area of normal vision

Front 10

Result of lesion to optic chiasm

Back 10

Bitemporal hemianopia.

Loss of temporal/lateral visual fields bilaterally. Those are the fibers that cross.

Have only medial fields.

Front 11

The area representing (temporal, nasal) vision is the part that crosses in the optic chiasm.

Back 11

Temporal

Front 12

Result of lesion to the left optic tract

Back 12

Loss of vision of entire right visual field.
<b>Right homonymous hemianopia</b>

Front 13

Papilledema: what is usually spared (unless very severe)?

Back 13

Visual acuity; Color Vision

Front 14

Optic neuropathy: defn

Back 14

Refers to any cause of damage to optic nerve.

Front 15

Optic neuritis: defn

Back 15

Inflammation of optic nerve.

Most commonly demyelinating.

Front 16

Optic neuritis: two presentations

Back 16

1) Papillitis - inflam of prelaminar portion --> swollen optic disc

2) Retrobulbar optic neuritis - inflam behind prelaminar portion --> normal appearing optic disc

Front 17

Optic disc edema: two causes

Back 17

1) Papilledema
2) Papillitis (optic neuritis affecting optic disc)

Front 18

How to distinguish papilledema from papillitis? (They both cause optic disc edema)

Back 18

Papilledema:

-occurs bilaterally
-preserved visual acuity
-preserved color perception
-enlarged blind spot
-NO afferent pupillary defect

Front 19

Most common causes of optic chiasm lesions

Back 19

Tumors (pituitary, etc)
Aneurysm
Trauma

Front 20

Most common causes of optic radiation/occipital lobe damage

Back 20

Vascular: ischemic infarct or hemorrhage

(Other causes include tumor, infection, and inflammation)

Front 21

Optic neuritis: Four cardinal features on examination

Back 21

1. Visual acuity is impaired
2. Color vision (red green) is impaired
3. Visual field is impaired:
Central scotoma
Arcuate defect
Other
4. Pupil is impaired: afferent pupillary defect

Front 22

type of anopsia where the decreased vision or blindness takes place in half the visual field of one or both eyes

Back 22

hemianopia

Front 23

loss of half of the visual field on the same side in both eyes.

Back 23

homonymous hemianopia

Front 24

loss of half of the visual field on different sides in both eyes

Back 24

Heteronymous hemianopsia (either binasal or bitemporal)

Front 25

Light-near dissociation: defn

Back 25

pupil reacts better to near response than to light response

Front 26

Near response: defn

Back 26

focus at near results in constriction of both pupils

Front 27

Parasympathetic stimulation (constricts, dilates) pupils while sympathetic stimulation (constricts, dilates) pupils.

Back 27

Constricts; Dilates

Front 28

Afferent Pupillary Defect (APD) is aka

Back 28

Marcus Gunn Pupil

Front 29

Afferent Pupillary Defect (APD): defn and cause

Back 29

Deficit in afferent visual pathway (typically optic nerve).

NO Anisocoria

Front 30

T/F There is anisocoria in Afferent Pupillary Defect.

Back 30

F

Front 31

Innervation of pupillary dilator and levator palpebrae: What is path?

Back 31

Sympathetic neuron comes from superior cervical ganglion --> Travels up carotid thru cavernous sinus ---> passes thru ciliary ganglion (no synapse) --> innverates pupillary dilator and sympathetic lid function

Front 32

Innervation of pupillary constrictor muscle: What is path?

Back 32

Parasympathetic fibers begin in Edinger-Westphal nucleus --> Ride with CN III to posterior ciliary ganglion --> *synapse in ciliary ganglion* --> secondary fibers pass to pupillary constrictor.

Front 33

Pupillary Light Reflex: What is path?

Back 33

1) Light stimulus impacts retina and is transmitted through optic nerve

2) Pupillary fibers in optic n. diverge from vision fibers in the optic chiasm.

3) Pupillary fibers synapse on pre-tectal nuclei.

4) Fibers pass to Edinger-Westphal n. to initiate parasympathetic pupillary constriction.

*Light stimulus in either eye will be transmitted to BOTH Edinger-Westphal nuclei, resulting in equal pupillary constriction for both eyes.

Front 34

Adie's tonic pupil: cause

Back 34

damage to ciliary ganglion

Front 35

Adie's tonic pupil: symptoms

Back 35

Dilated pupil with Light-Near dissociation.

Responds poorly to bright light stimulus, but better (still sluggish) to near stimulus.

Front 36

Toxic pupil: defn

Back 36

Dilated pupil due to anticholinergic poisoning (atropine, jimson weed/scopolamine).

Front 37

Traumatic dilated pupil: defn and cause

Back 37

Results from injury to iris muscles

Front 38

pilocarpine: MOA and effects

Back 38

parasympathomimetic. Muscarinic receptor agonist.

Constricts pupil.

Front 39

T/F In toxic pupil, neither pilocarpine, light, nor near response will cause constriction.

Back 39

T

Front 40

T/F In Adie's tonic pupil, neither pilocarpine, light, nor near response will cause constriction.

Back 40

F. Both near response and pilocarpine will constrict it.

Due to lesion of ciliary ganglion.

Front 41

Horner syndrome: Cause

Back 41

Sympathetic denervation to face

Front 42

Horner syndrome: symptoms

Back 42

Miosis: constricted pupil

Ptosis: Droopy eyelid due to lack of levator palpebrae function

Anhydrosis (lack of sweating)

Front 43

Physiologic/central anisocoria is observed in about ___% of population.

Back 43

20

Front 44

Argyll-Robertson Pupils: defn and cause

Back 44

bilaterally miotic and irregular pupils classically result of tertiary syphilis.

No light reflex, but near response is intact.

Front 45

Marcus Gunn Phenomenon: Defn and Cause

Back 45

AKA Afferent pupillary defect.

Light stimulus in affected eye produces no constriction in either eye.

Light stimulus in unaffected eye produces constriction in both eyes.

Due to an afferent lesion of visual pathways, usually anterior to optic chiasm.

Front 46

T/F Horner syndrome dilation is same in dim and bright light.

Back 46

F. It's usually more dilated in dim light.

Front 47

vestibulo-ocular reflex: defn

Back 47

stabilizes eyes for balance

Front 48

Medial longitudinal fasciculus connects what?

Back 48

CN 3 nucleus (controls medial rectus) with the contralateral CN 6 nucleus (controls lateral rectus). Allows for conjugate lateral eye movements.

Front 49

Parapontine reticular formation (PPRF): what is it?

Back 49

Final common path that drives eyes conjugately in horizontal plane.

That is, stimulation of Right PPRF drives eyes to Right.

Front 50

CN III palsy: symptoms

Back 50

Eye drifts down and out (paralysis of adduction and elevation)

Front 51

CN VI palsy: symptoms

Back 51

Paralysis of abduction

Front 52

CN IV palsy: symptoms

Back 52

subtle inability to adduct and intort eye on depression (superior oblique).


Ask patient to look IN and then DOWN

Front 53

Internuclear ophthalmoplegia (INO): defn and cause.

Back 53

Paralysis of ADDUCTION to side ipsilateral to lesion.

Due to lesion of MLF (medial longitudinal fasciculus), the path where the CN III and CN VI fibers cross contralaterally for conjugate lateral gaze.

Lesion of Right MLF results in right INO causing paralysis of adduction of right eye associated with abducting nystagmus of left eye.

Front 54

Frontal lobe relation in conjugate gaze disorders

Back 54

If there is damage to a frontal lobe, the eyes deviate towards the SIDE OF THE LESION due to overacting tone of contralateral front lobe.

Front 55

Doll's head maneuver: defn

Back 55

Rapidly turning head side to side will cause eyes to deviate to side opposite from where head is turned.

Front 56

In PPRF lesions, eyes can't look (ipsi, contra) laterally to the lesion.

Back 56

ipsilaterally (Right PPRF lesion --> loss of Right conjugate gaze)

Front 57

Which may be overcome by the Doll's Head Maneuver (vestibulo-ocular reflex)?
A) PPRF Lesion
B) Frontal lobe lesion

Back 57

A) No
B) Yes

Front 58

Pathologic nystagmus seen most commonly in what disorders?

Back 58

Disorders of inner ear - results in horizontal - rotary jerk nystagmus consisting of slow and fast phase + vertigo and nausea

Front 59

Pathway for VERTICAL gaze

Back 59

Rostral interstitial MLF (riMLF)

Front 60

Dorsal midbrain syndrome (Parinaud’s syndrome)—defn and cause

Back 60

supranuclear paralysis of upgaze

Due to pineal tumor, ischemia, or trauma.

Front 61

Internuclear ophthalmoplegia (INO) : cause

Back 61

dymyelinating disease, ESPECIALLY MS

Front 62

Horner's syndrome is associated with spinal cord lesion above ___.

Back 62

T1

Front 63

High-acuity central vision

Back 63

macula

Front 64

high concentration of cones in center

Back 64

fovea

Front 65

Type of receptor for the following:
A) pupillary dilator/radial muscle
B) sphincter/circular/constrictor muscle

Back 65

A) &alpha;1
B) M3

Front 66

eye drifts upward, causing vertical diplopia in CN __ damage

Back 66

IV

Front 67

CN III cross section

Back 67

Center: output to ocular muscles. Affected by vascular disease (DM) due to increased diffusion to interior.

Periphery: parasympathetic output. Affected first by compression. Use pupillary light reflex in assessment.

Front 68

A Right temporal lesion causes what visual deficit?

Back 68

Left upper quadrant anopsia

Front 69

A Right parietal lesion causes what visual deficit?

Back 69

Left lower quadrant anopsia

Front 70

A right visual cortex lesion causes what visual deficit?

Back 70

Left hemianopia with macular sparing

Front 71

Macular degeneration causes what visual deficit?

Back 71

Central scotoma (loss of central vision)

Front 72

Dorsal optic radiation (parietal) is associated with (inferior, superior) retina while Meyer's loops (temporal lobe) is associated with (inferior, superior) retina.

Back 72

Superior; Inferior

Front 73

The RIGHT MLF connects the (left, right) CN 3 nucleus with the (left, right) CN 6 nucleus.

Back 73

Right; Left