Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

From Flashcardlet > Neuro-Ophthalmology: 7b. The Patient with Supranuclear Motility Disorders > Flashcards

Neuro-Ophthalmology: 7b. The Patient with Supranuclear Motility Disorders Flashcards

0
Q

30

A

the pursuit system is capable of following an object if it moves less than this many degrees per second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

object detection

A

basic function of the extrafoveal retina (in a monocular sense)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

VOR

A

allows the eyes to track an object during brief head rotation (such as during walking)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

OKN

A

allows the eyes to track an object during prolonged head rotation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

microsaccadic refixation movements

A

when gaze is held on an object this prevents attenuation of the neuronal response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

velocity storage mechanism

A

VOR system that prevents rapid attenuation of the response during periods of extended stimulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

spontaneous nystagmus

A

the hallmark of an uncompensated vestibular imbalance, this form of nystagmus is observed in primary position, though it can be suppressed by visual fixation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

right

A

eye drifting (slow phase of nystagmus) to the right indicates dysfunction of the vestibular system on THIS side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

head shaking

A

if the patient is prevented from fixating by Frenzel goggles, high plus lenses, or by holding eyes closed, this can induce spontaneous nystagmus in a patient with vestibular imbalance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

VOR gain

A

deficit in this measured by turning the head abruptly to the side of the lesion by 10 degrees and measuring the eye response (checking for the presence of a refixation saccade) - more sensitive than head shaking

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

dynamic visual acuity

A

test for bilateral vestibular dysfunction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

main sequence

A

dictates that larger amplitude saccades are faster than lower amplitude saccades

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

pulse

A

encodes eye movement velocity required to reach an eccentric target

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

step

A

encodes eye movement amplitude to hold the eye in an eccentric position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

paraflocculus

A

part of the cerebellum that contributes to pursuit movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

1

A

normal gain of eye movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

square-wave jerk

A

most common type of saccadic intrusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

PSP, cigarette smoking

A

two major associations of SWJs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Wallenburg syndrome

A

stroke syndrome that commonly causes an ocular tilt reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

vertebral artery

A

usual vessel occluded in Wallenburg syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

lateropulsion

A

the sensation of being pulled toward the side of a vestibular defect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

multiple sclerosis, cerebellum

A

impaired VOR suppression is commonly seen in this disease and typically reflects dysfunction here

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

parietal-occipital cererbrum

A

asymmetry of the OKN response typically indicates damage to these areas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

false

A

TRUE or FALSE: An occipital stroke can produce asymmetry of the OKN response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

PSP

A

in this disorder, voluntary saccadic latency tends to be affected earlier than reflexive saccadic latency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

central

A

slow saccades of normal amplitude: central or peripheral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

peripheral

A

slow hypometric saccades: central or peripheral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

cerebellum

A

hypermetric saccades typically localize dysfunction here

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

myasthenia gravis

A

“lighting-like” hypermetric saccades

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

up

A

reduced saccadic amplitude in this direction (but of normal velocity) is typical of normal aging

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Wallenburg syndrome

A

unidirectional hypermetric saccades, ocular lateropulsion, hypermetric pursuit movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

ataxia telangiectasia, Tay Sachs disease, Niemann-Pick DIsease Type C, Pelizaeus-Merzbacher disease, Gaucher disease, Joubert syndrome, abetalipoproteinemia, Wilson Disease

A

eight disease associations of congenital ocular motor apraxia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

anoxic encephalopathy

A

typical association of acquired ocular motor apraxia (saccadic initiation failure)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Balint syndrome

A

combination of optic ataxia, saccadic dysfunction, and simultagnosia

34
Q

Mobius syndrome

A

congenital syndrome associated with horizontal gaze palsy

35
Q

pretectum

A

structure damaged in Parinaud syndrome

36
Q

artery/arteries of Percheron

A

stroke at the site of this/these arteries can cause Parinaud syndrome

37
Q

tonic downgaze

A

motility pattern if observed in children, often heralds disaster

38
Q

oculogyric crisis

A

a tonic upward eye-movement deviation, sometimes directed toward the right or left, that does not disrupt a patient’s ability to move the eyes within the involved area

39
Q

smooth pursuit, OKN

A

two systems that keep objects from “sliding” across the retina

40
Q

VOR

A

system that keeps the movements of the head from causing objects to slide across the retina

41
Q

volitional, OKN fast phase

A

two main types of saccades that are commonly tested

42
Q

saccades, smooth pursuit, near convergence, VOR

A

four basic types of supranuclear movements that must be tested

43
Q

step

A

term for the difference between the pulse and the innervational plateau in performing a saccade

44
Q

PPRF

A

Injury to this structure causes an ISOLATED horizontal gaze palsy

45
Q

abducens nucleus

A

injury to this structure causes both a horizontal gaze palsy AND paretic strabismus

46
Q

right saccades

A

In a patient who actually has a complete right CN VI palsy (in contrast to a functional), this should be impaired in the involved eye

47
Q

true

A

TRUE or FALSE: a patient with complete dysfunction of the right PPRF will be able to follow the examiners finger to the right side (DOUBLE CHECK THIS QUESTION)

48
Q

frontal eye field

A

a complete dysfunction of this structure will never cause a gaze palsy but will make it impossible to look opposite the direction of an object of interest

49
Q

internal capsule

A

strokes that cause gaze palsy (usually only 1 to 2 weeks) only do so by damaging this structure

50
Q

riMLF

A

isolated upgaze palsy is caused by damage to this structure

51
Q

nucleus of Cajal, NPH

A

these nuclei integrate the pulse data to generate the appropriate step function (dysfunction causes gaze-evoked nystagmus)

52
Q

upward saccades, light reflex

A

these functions are extinguished by a lesion that destroys the posterior commisure

53
Q

oculomotor apraxia

A

this disorder causes selective impairment of voluntary saccades

54
Q

congenital oculomotor apraxia

A

Which is purely horizontal, congenital oculomotor apraxia, acquired oculomotor apraxia (very rare), or both?

55
Q

tranquilizers, antiseizure medications

A

two basic types of medications that should be searched for in cases of

56
Q

hypermetric saccades

A

which are ALWAYS pathologic, hyper metric saccades or hypometric saccades

57
Q

left-sided Wallenberg syndrome

A

causes left saccadic lateropulsion (hypermetric to the left, hypometric to the right)

58
Q

cerebellar vermis

A

hypermetric saccades almost always localize here

59
Q

INO

A

classic cause of a dissociated gaze-evoked nystagmus

60
Q

ipsilateral deep parieto-occipital, contralateral pontine, ipsilateral cerebellar (paraflocculus)

A

three general loci for impaired smooth pursuit mechanisms

61
Q

suppression of the VOR

A

mechanism to test smooth pursuit that does NOT involve moving the eyes (helpful in a person with gaze-evoked nystagmus)

62
Q

OKN

A

if the VOR system is attenuated (say by continuous head rotation), this system is used to supplement smooth pursuit of a moving object during head rotation

63
Q

OKN

A

this system hijacks the vestibular nuclei and cortical pathways but does not require vestibular input

64
Q

spontaneous nystagmus

A

the hallmark of vestibular imbalance

65
Q

Balint syndrome

A

extremely rare combination of acquired oculomotor apraxia, optic ataxia, and simultagnosia

66
Q

optic ataxia

A

reaching to shake someone’s hand and missing it even though a person can can see it

67
Q

Mobius syndrome

A

this congenital syndrome is often associated with a bilateral GAZE palsy (no horizontal movement AT ALL)

68
Q

doll’s head maneuver

A

may be useful to rule out dorsal midbrain syndrome in a newborn with tonic downward eye deviation

69
Q

bilateral lateral gaze paresis

A

reason that pontine lesions cause ocular bobbing

70
Q

Parinaud’s syndrome

A

quick name association: tonic downward deviation

71
Q

oculogyric crisis

A

quick name association: tonic upward deviation

72
Q

high-potency traditional antipsychotics

A

most common cause of oculogyric crisis today

73
Q

horizontal semicircular canal

A

sensory structure activated by sideways head turn

74
Q

utricle and saccule

A

sensory structure activated by acceleration of a car

75
Q

yoke muscles

A

each semicircular canal is linked to a pair of these

76
Q

dynamic visual acuity

A

test for bilateral subnormal VOR gain

77
Q

pursuit system

A

in humans, this is actually more important than the OKN in maintaining ocular stability during sustained (>30 sec) head rotation

78
Q

paraflocculus

A

cerebellar structure that plays an important role in the pursuit system

79
Q

cerebellum

A

impairment of VOR suppression is common in this disease process and localizes dysfunction here

80
Q

PSP

A

patients with this disorder (early on) characteristically show impaired volitional saccades but intact reflexive saccades (such as when using an OKN drum)

81
Q

slowed, hypometric

A

describe a peripheral impaired saccade

82
Q

slowed, normal amplitude

A

describe a central impaired saccade

From Flashcardlet (61 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions