Ocular Disease Iii - Chiasm/postchiasm

Front 1

Would you expect an APD with a damaged ciliary ganglion?

Back 1

No - causes efferent pupillary defect

Front 2

Would you expect an APD with a pituitary tumor?

Back 2

Yes if asymmetric

Front 3

Would you expect an APD with an optic tract lesion?

Back 3

Yes

Front 4

Would you expect an APD with an LGN lesion?

Back 4

No b/c pupil and visual fibers split before this point

Front 5

Would you expect an APD with occipital lobe trauma?

Back 5

No

Front 6

What vessel is lateral to the chiasm?

Back 6

Int carotid a.

Front 7

The optic tract terminates at the...

Back 7

LGN

Front 8

In binasal VF loss you must consider glaucoma and this kind of lesion...

Back 8

bitemporal chiasm lesion

Front 9

Pupillomotor fibers leave the ____ anterior to the LGN and enter the _____ area.

Back 9

optic tract, pretectal

Front 10

The ___ is the endpoint for afferent fibers of the anterior visual pathways.

Back 10

LGN

Front 11

The Visual Radiations are aka...

Back 11

Optic Radiations, Geniculocalcarine Tract

Front 12

What is Meyer's Loop?

Back 12

Anterior-inferior retinal fibers form a bend and continue around a projection of inferior retinal fibers (superior visual field) and passes around or near tip of temporal ventricular horn
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Basically a detour of the inferior retinal fibers thru temporal lobe (hence "TS" in PITS - temporal lobe = sup VF = inf retina)

Front 13

Optic radiations end in...(be specific)

Back 13

visual cortex (striate cortex) in the occipital lobe

Front 14

The macular region is 1-2 cm (laterally/medially) in the posterior surface of the occipital lobe.

Back 14

laterally

Front 15

The visual cortex extends anteriorly toward the ____ of the ___.

Back 15

splenum, corpus callosum

Front 16

The visual cortex is separated into left and right halves by the ____, and superior and inferior halves by the ___.

Back 16

longitudinal cerebral fissure, calcarine fissure

Front 17

Area 18 is aka...

Back 17

Parastriate cortex

Front 18

Area 18 fxn?

Back 18

Integrate two halves of the visual fields via interhemispheric commisural pathway that traverses the splenum of corpus callosum; participates in sensory motor eye coord via fronto-occipital pathways (origin of smooth pursuit pathway)

Front 19

Area 19 is aka...

Back 19

Peristriate cortex

Front 20

Area 19 fxn?

Back 20

Major center for integration of visual information

(yeah, that's what the slide says...)

Front 21

T/F - Vast majority of nerve fibers from the retina to the occipital cortex related to arcuate fibers.

Back 21

False - papillomacular bundle

Front 22

Peripheral retina axons are (smaller/larger) caliber and tend to be distributed toward the (center/periphery)

Back 22

larger, periphery

Front 23

T/F - Fibers that originate in the inferior retina remain inferior in the nerve and chiasm

Back 23

True

Front 24

What occipital lobe structure splits the horizontal midline of the VF?

Back 24

calcarine fissure

Front 25

What defines the vertical meridian of the visual fields in the visual cortex?

Back 25

periphery of the striate cortex

Front 26

T/F - The correct cortical representation is: up is down, left is right.

Back 26

True

Front 27

T/F - The most anterior cortical representation in the visual cortex is the macula.

Back 27

False - posterior

Front 28

T/F - The striate visual cortex represents the peripheral VF.

Back 28

False - central

Front 29

The 30-2 VF screener will test __% of the cortex.

Back 29

80

Front 30

A patient can lose their temporal crescent if a lesion was located at the (posterior/anterior) visual cortex and on the (contra/ipsi)lateral side.

Back 30

anterior, contra

Front 31

The majority of chiasmal disorders are caused by...

Back 31

extensive tumors (pituitary adenomas, suprasellar meningiomas, craniopharyngioma)

Front 32

Chiasm VF loss is typically (asymmetrical/symmetrical)?

Back 32

asymmetrical

Front 33

You're checking the VAs of your pituitary adenoma pt - what kind of responses would you expect (assuming emmetropia and no other visual problems)?

Back 33

Right eye - only left letters seen
Left eye - only right letters seen

(remember pituitary adenoma affects chiasm, causing bitemporal hemianopsia)

Front 34

A person with a dense bitemporal hemianopsia and a significant phoria can present with ___. Why?

Back 34

Hemi-field slip; VFs will be misaligned (either vert or horz)

Front 35

What kind of ONH sign can you possibly see in chiasmal lesions?

Back 35

ONH pallor - not a prereq in Dx! Only ~50% had optic atrophy. May not show up after 2 yrs of visual Sx. See Bowtie atrophy.

Front 36

What pattern of atrophy can be seen with chiasmal lesions? What retinal bundle(s) is/are spared in this atrophy?

Back 36

Bowtie atrophy. Arcuates are spared - these are responsible for temporal retina, nasal VF. Thus temporal VF affected, hence bitemporal VF defect

Front 37

What is the main factor that helps you DDx temporal hemianopsia VF defects vs tilted discs (inferior crescents), nasal sector RP, bilateral centrocecal scotomas, and upper lid fissure hanging over?

Back 37

the latter tend not to respect the midline

Front 38

Most common cause of pituitary syndromes? 2nd? 3rd? 4th?

Back 38

In order: Pituitary tumors, Craniopharyngiomas, Meningiomas, Gliomas

Front 39

Congenital anomalies of the optic disc may indicate presence of occult _____ malformations.

Back 39

forebrain

Front 40

Pituitary tumors usually does not occur until age...

Back 40

20

Front 41

Acromegaly, amenorrhea, galactorrhea, hyper/hypothyroidism, or adrenocorticotropia make you think there's a problem in the...

Back 41

pituitary (pituitary adenoma)

Front 42

T/F - 2/3 of pituitary adenoma pts have chronic HAs.

Back 42

True

Front 43

Non-ocular Sx of pituitary adenoma?

Back 43

Chronic HAs, fatigue, impotence, amenorrhea, sexual hair change (gonadal, thyroid, adrenal insufficiency)

Front 44

If a pituitary adenoma grew in underneath the front of the chiasm, you expect a VF more defect dense in the...

Back 44

superior temporal

Front 45

If a pituitary adenoma grew posterior and above the chiasm, you expect a VF more defect dense in the...

Back 45

inferior temporal

Front 46

T/F - Most pituitary adenomas grow anteriorly.

Back 46

False

Ant = 25%
Middle = 65%
Post = 10%

Front 47

Prolactinoma Sx?

Back 47

Males: decr libido, gynecomastia, impotence

Females: amenorrhea, galactorrhea, infertility, decr libido, secondary osteoporosis

Front 48

Mx of Prolactinomas?

Back 48

Bromocryptine (Parlodel), Cabergoline (Dostinex), Quinaglolide (Norprolac), or exision

Front 49

How does Bromocryptine (Parlodel) work?

Back 49

Inhibit pituitary gonadotropin fxn, reduce prolactin secretion & size of prolactinoma

Front 50

Most common secreting pituitary adenoma?

Back 50

Prolactinomas

Front 51

What are transphenoidal hypophysectomies used for?

Back 51

Removal of pituitary adenoma; may be difficult to remove tumor b/c 40% have dural invasion; decompresses the visual pathway

Front 52

Meningiomas are (fast/slow) progressing, usually (bilat/unilat).

Back 52

slow, unilat (if bilat, usually markedly asymmetric)

Front 53

What are optic disc shunt vessels? These are seen in?

Back 53

Normally present BVs at the ONH but are dilated; DDx vs neo at the disc. Seen in meningiomas.

Front 54

Sx of meningiomas?

Back 54

Non-specific HAs, monocular vision loss with fluctuations over months/weeks.

Front 55

Signs of meningiomas?

Back 55

Asymmetric optic disc pallor (later sign), Foster Kennedy Syndrome (optic atrophy and contralateral papilledema)

Front 56

What is Foster Kennedy Syndrome?

Back 56

Seen in meningiomas - optic atrophy and contralateral papilledema

Front 57

Mx meningioma?

Back 57

Surgery via frontal craniotomy, then repeat VFs to detect recurrence of tumor

Front 58

Locations of menigioma?

Back 58

Tuberculum sella and anterior clinoid

Front 59

Meningioma at tuberculum sella causes this VF defect. Why?

Back 59

Junctional scotoma (ipsi central scotoma, contra superior quadrant defect) - b/c pushing on knee of von willebrand on anterior and inferior of chiasm.

Front 60

Describe the presentation of a junctional scotoma. This is present in what type of tumor?

Back 60

ipsi central scotoma, contra superior quadrant defect.

In meningiomas located at tuberculum sella (anterior and inferior to chiasm)

Front 61

Craniopharyngiomas arise from?

Back 61

vestigial epidermoid remnants of Rathke's pouch

Front 62

What type of lesion describes solid cellular components and cyts containing degenerated and necrotic tissue?

Back 62

Craniopharyngiomas

Front 63

*T/F - Papilledema can occur in Craniopharyngiomas

Back 63

True - particularly in childhood Craniopharyngiomas

Front 64

What chiasmal lesion has a bimodal age distribution?

Back 64

Craniopharyngiomas
Children: 1st 2 decades
Adults: 50-70 yrs

Front 65

Sx of childhood Craniopharyngiomas?

Back 65

progressive vision loss that goes unnoticed until severe loss occurs, HAs, vomiting, behavioral changes, obesity, delayed sexual dev, somnolence (drowsiness)

Front 66

Craniopharyngiomas have what signs?

Back 66

possible optic atrophy and papilledema

Front 67

Initial Sx of adult Craniopharyngiomas?

Back 67

VF defects or decr acuity

Front 68

Adult Craniopharyngiomas are typically (symmetric/asymmetric) and involve these kinds of VF patterns...

Back 68

asymmetric

bitemporal hemianopic or homonymous (indicating optic tract involvement)

Front 69

Craniopharyngiomas tend to grow in the (inf/sup) (ant/middle/post) portion of this structure. What kind of VF defect is expected?

Back 69

superior posterior chiasm; more dense inferior temporal

(anterior = more dense superior temporal)

Front 70

Mx Craniopharyngiomas?

Back 70

total to partial removal with reduction Tx; removal is difficult b/c adhesions to ON, chiasm, carotid arteries, hypothalamus; endocrine replacement Tx in all cases

Front 71

Diffuse meningeal carcinomatosis result in? How did this occur?

Back 71

unilat or bilat visual loss mimicking optic neuritis

Due to metastasis from breast or lung thru subarachnoid space

Front 72

T/F - Pregnancy adversely influences demyelinative disease

Back 72

False - no real evidence to conclude this

Front 73

T/F - Intracranial tumors are known to undergo growth spurts during pregnancy.

Back 73

True (receptors in meningiomas, and normal enlargement of pituitary)

Front 74

What is empty sella syndrome?

Back 74

Extension of subarachnoid space into sella turcica thru deficient sellar diaphragm; can mimic pituitary adenoma

Front 75

Post-chiasmal lesions cause what kind of VF loss, on what side?

Back 75

contralateral homonymous VF loss

Front 76

VF loss congruity increases as you go more (post/ant) in the visual pathway?

Back 76

post

Front 77

Is it possible to have an APD in a lesion that is post-chiasmal?

Back 77

yes, because optic tract lesions still can produce APDs, and the optic tract is the last part of the visual pathway before the LGN

Front 78

Of these potential lesion sites causing a VF defect, order in least to most likely in vascular etiology:
Occipital, Temporal, Parietal

Back 78

Temporal, Parietal, Occipital

i.e. occipital most likely to get stroke vs temporal lobe; note that stroke more in older pts

Also note that the order is reverse for likelihood of tumor etiology i.e. temporal = caused by tumor

Front 79

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Localize the lesion causing this VF defect.

Back 79

Can't localize specifically b/c complete fixation splitting homonymous hemianopsia; can be at tract, temporal + parietal, occipital, etc.

Front 80

An inferior homonymous hemianopsia more dense inferiorly localizes to...

Back 80

parietal lobe

PITS: Parietal Inferior, Temporal Superior

Front 81

What retinal fibers are within the optic tract (be specific with ipsi and contralateral)?

Back 81

- Ipsilateral superior and inferior arcuate bundles
- Contralateral nasal radial fibers
- Contralateral PM bundle

Front 82

The left optic tract receives more fibers from the left or right eye?

Back 82

right eye since the left optic tract receives the contralateral PM bundle (which has many fibers since macula has lots of information)

Front 83

T/F - this can be an optic tract lesion:
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Back 83

True if total interruption of optic tract (tends to be incongruous however)

Front 84

If this is a total interruption of the optic tract, where is it localized?
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Back 84

Left homonymous hemianopsia is caused by right tract lesion

VF defect is contralateral to lesion in optic tract lesions

Front 85

If this is a total interruption of the optic tract, in what eye would you expect an APD?
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Back 85

Right tract lesion so can see a trace APD in left eye.

(APD same side as VF defect)

Front 86

You see bowtie atrophy in the OD, arcuate defects in the OS. What type of lesion? Localized?

Back 86

Right optic tract atrophy

Bowtie on the same side as the lesion

Front 87

Optic atrophy in optic tract damage takes __ weeks to develop.

Back 87

6

Front 88

T/F - Optic tract damage results in decreased VA.

Back 88

False - VA is normal unless chiasm is affected

Front 89

Describe the VF defects found in optic tract damage. They are (contra/ipsi)lateral to the lesion and are (congruous/incongruous)

Back 89

Partial homonymous hemianopsia

Contra, incongruous (marked)

Front 90

T/F - You expect the contralateral nasal hemi-retina to be much more extensive than ipsilateral temporal hemi-retina in optic tract damage.

Back 90

True - note that nasal hemi-retina includes PM bundle

Front 91

Pure Tract syndrome are usually associated with...

Back 91

Pituitary adenomas, int carotid aneurysms, optic chiasm gliomas

Front 92

Mx Optic tract lesions?

Back 92

Req definitive neuroradiologic investigations (CT, MRI, carotid/vertebral angiography, CSF analysis)

Front 93

LGN VF defects look like...

Back 93

Either hourglass shaped or homonymous sector triangular defects

Front 94

Destruction of the LGN results in this kind of VF defect...

Back 94

complete, absolute, fixation splitting, contralateral homonymous hemianopsia

Front 95

You see disc pallor but no APD - you suspect a lesion where?

Back 95

LGN

Front 96

You are looking at your pt's VF and note definite homonymous defects, but you're not quite sure...but your pt has paresis of the left side. What do you suspect, and where specifically?

Back 96

Right temporal lobe INFARCT (not tumor) or LGN lesion - involves contralateral homonymous VF defects and contralateral paresis

Front 97

Which is a temporal lobe VF defect (OD, OS)?
A) superior temporal, superior nasal
B) superior temporal, superior temporal
C) inferior temporal, inferior nasal
D) inferior temporal, inferior temporal
E) inferior nasal, inferior nasal

Back 97

A) superior temporal, superior nasal

This describes a homonymous hemianopsia, more dense superior in temporal lesions

Front 98

T/F - You can see a trace APD in temporal lobe lesions.

Back 98

False - past LGN!

Front 99

T/F - VAs are normal in temporal lobe lesions.

Back 99

True

Front 100

T/F - You can get disc pallor in temporal lobe lesions.

Back 100

False

Front 101

T/F - Temporal lobe lesions can be congruous or incongruous

Back 101

True

Front 102

T/F - Temporal lobe lesions can extend to inferior quadrant.

Back 102

True

Front 103

If you get an incongruous VF defect in a left temporal lobe lesion, which eye has a denser defect?

Back 103

LE - denser on same side as lesion

Front 104

T/F - Temporal lobe lesions are more likely vascular in etiology.

Back 104

False - more likely neoplastic

"Tumor = Temporal"

Front 105

Sx of Temporal lobe lesions?

Back 105

- Memory loss (permanent or temporary)
- Aphasia
- Contralat hemiparesis

Front 106

T/F - A right temporal lobe lesion due to infarct involves paresis of the right side.

Back 106

False - left side

Front 107

Temporal lobe lesions are usually caused by what type of tumor? What is the ratio of Tumor:Vascular etiology?

Back 107

Gliomas, 9:1

Front 108

Your pt notices odd smells at random times and also "sees things". You also notice he has a hard time trying to express what he wants to say. You suspect...

Back 108

temporal lobe lesion caused by tumor

Front 109

Parietal + temporal lobe lesion combined would cause this type of VF defect...

Back 109

complete homonymous hemianopsia

Front 110

Your pt has a right incongruous homonymous hemianopsia. Puzzled, you check for an APD and look at the fundus and saw nothing interesting. You suspect...

Back 110

Either left temporal or parietal lobe lesion

Front 111

T/F - Parietal lobe lesions are associated with extinction phenomenon (finger counting)

Back 111

True

Front 112

Parietal lobe lesions have a ____ type VF defect more dense where?

Back 112

homonymous hemianopsia more dense inferiorly

Front 113

T/F - Parietal lobe lesions involve a normal fundus and pupil function.

Back 113

True

Front 114

T/F - Parietal lobe lesions involve a decrease in VA.

Back 114

False

Front 115

T/F - Parietal lesions are more likely vascular in etiology.

Back 115

False - same probability of vascular:tumor (1:1)

Front 116

What type of lesion in the visual pathway can involve an asymmetric OKN?

Back 116

Parietal lobe (horz OKN)

Front 117

You rotate an OKN drum so that the pt is seeing the target spin to the right, and you see a diminished OKN response. What type of lesion and where?

Back 117

Right parietal lobe lesion

Lesion is located at same side of where the target is rotated toward

Front 118

You ask your pt to draw a clock and you notice that it looks weird. Also, his wife complains that he gets lost in his own home a lot. You suspect...

Back 118

parietal lobe damage

Front 119

T/F - Temporal lobe lesions can involve stereo loss.

Back 119

False - parietal

Front 120

Your pt's homonymous hemianopsia is highly congrouous - this pretty much says that the lesion is most likely at...

Back 120

the occipital lobe

Front 121

T/F - Occipital lobe lesions can involve congruous scotomas, quadranopsias, and full hemianopsias.

Back 121

True

Front 122

How is the macula spared in some occipital lobe lesions?

Back 122

Dual arterial supply to occipital lobe (post cerebral and middle cerebral)

Front 123

Your pt has a homonymous hemianopsia that is more dense superior. You also notice that the central four threshold numbers are normal. You suspect...

Back 123

macular sparing occipital lobe lesion

Front 124

T/F - Occipital lobe lesions are most likely vascular.

Back 124

True - esp stroke

"Occipital = Occlusive (esp stroke)"

Front 125

Chance of vascular etiology in occipital lobe lesions?

Back 125

7:1

Front 126

Most common cause of homonymous VF defects in middle aged to elderly?

Back 126

occipital lobe infarct

Front 127

Why is the occipital lobe prone to stroke?

Back 127

Watershed zone - highly vascular but incr chance of infarct

Front 128

Diplopia, oscillopsia, bilateral "gray-out", transient hemianopsia, homonymous photopsia, and bilateral photopsia are Sx of...

Back 128

occipital lobe lesions

Front 129

T/F - Facial paresthesias can be caused by occipital lobe lesions.

Back 129

True

Front 130

T/F - Tinnitus can be caused by occipital lobe lesions.

Back 130

True

Front 131

There was one condition where you can see decr VAs in a post-LGN lesion. What is this?

Back 131

Cortical blindness - it is a bilateral involvement of any structure past the LGN, including the occipital lobe; causes central VF defects

Front 132

Bitemporal hemianopsia should make you think automatically that the lesion is at the...

Back 132

chiasm

Front 133

What is 917 TPO?

Back 133

Etiologies of...
Temporal = 9 tumor:1 vascular
Parietal = 1 tumor:1 vascular
Occipital = 7 vascular:1 tumor

Front 134

Stereo and OKN problems alert you automatically to this visual pathway lesion...

Back 134

Parietal

Front 135

Perfect quadranopsias signal you to think...

Back 135

occipital or radiations

Front 136

LGN VF defects are on the (contra/ipsi)lateral side of the lesion.

Back 136

contra

Front 137

Cushing's could be associated with this type of VF defect...

Back 137

Pituitary adenoma causing bitemporal hemianopsia

Adrenocorticotropia = Cushing's