602 - Lecture 6, Chapter 5 Mid Term 2

Front 1

why is an OKN drum used in office not suitable for testing OKN

Back 1

because a busy background can cause pursuits to occur b/c pursuits doninate

Front 2

what is the velocity of a pursuit?

Back 2

up to 70deg/sec for non athletes and 130 for athletes

Front 3

what is the latency time for pursuit? is this faster of slower than saccades and VOR

Back 3

100 to 130 msec. so this is faster than saccades but slower than VOR

Front 4

the initiation phase of a pursuit is what? and when does it occur?

Back 4

the open loop phase and it occurs in the latency period

Front 5

what is the open loop phase triggered by?

Back 5

retinal slip which is the target moving on the retina.

Front 6

pursuit maintenance is done by what phase? this is where they are kept steady.

Back 6

the closed loop phase

Front 7

what is the efference copy?

Back 7

this is when eye velocity and estimated distance are used to calculate target velocity. this is done in the cerebellum

Front 8

is the trigger to begin a pursuit the same thing used to maintain it?

Back 8

no ideally there should be no slip while being maintained

Front 9

can any other senses be used to improve pursuit accuracy?

Back 9

yes senses like sound or proprioception can be used to help or even trigger a pursuit

Front 10

what are two areas of the brain that are used in both saccades and pursuits that have to do with voluntary and involuntary movement?

Back 10

FEF and the superior colliculus

Front 11

what portions of the brain are not used in saccades but are used in pursuits?

Back 11

the visual cortex v1 v2 v3, b/c in saccades we suppress

Front 12

what starts pursuits MT or MST.

Back 12

the MT which is global and periphery. starts when the retina sees retinal slip.

Front 13

most information travels via optic nerve to the ______to the V1-V5 then onward to the ______, _____, _______

Back 13

LGN to the V1 V5 then to the FEF pons and cerebellum

Front 14

some but not much of the signal coming in may travel straight to the _______(no really it does) and then to the _______, ______, ______

Back 14

nucleus of the optic (NOT)
then to the pons and cerebellum

Front 15

the rostral nucleus reticularis tegmenti pontis contains signals that cause what? (type of pursuit)

Back 15

verticle pursuits

Front 16

instead of verticle pursuits synapsing with the MVN they synapse with?
this "group" then talks to what?

Back 16

the y group which then talks to the INC

Front 17

what are some things that can cause pursuit deficit?

Back 17

busy backgrounds, target size, speed and unpredictable movement, mental state.

Front 18

gaze avoidance is associated with what type of patient?

Back 18

someone with a mental state like autism.

Front 19

tracking in patients with mental states may be reduced to what speed?

Back 19

30 deg/sec

Front 20

loss of vision in what will give you a scotoma? AKA?

Back 20

v1 or v5, akinetopsia

Note that the v5 is known as the medial temporal area.

Front 21

you have a patient that cannot see any pursuits left or right in the left hemi field, where is the damage?

Back 21

right, MT

Front 22

the parvo and magnocellular areas split up in what area of the cortex?

Back 22

mst (v3)

Front 23

a pt cannot see pursuits to the left in both left and right fields. where could a lesion be at?

Back 23

the left mst.
will also have a hemianopsia

Front 24

local motion (mst) is also called?

Back 24

optic flow

Front 25

ipsiversive horizontal pursuits are affected by lesions to the ____, ____, ______

Back 25

FEF, dorsolateral pontine nucleus and the nucleus of the optic tract.

Front 26

a upward pursuit deficit could be caused by a lesion in the

Back 26

rostral nucleus reticularis tenmenti pontis

Front 27

the primary structure involved in VOR cancellation is what

Back 27

the ventral paraflocculus (VPF)

Front 28

a lesion to one side of the ventral parafloculus will cause what type of problems

Back 28

mild affects both horizontal and vertical pursuits, also affects the VOR cancelation.

Front 29

a bilateral lesion of both the VPF and flocculus will cause what problems

Back 29

severe problems in pursuits and VOR will be uncontrolled

Front 30

bilateral lesions of the flocculus have what types of affects on pursuits?

Back 30

none

Front 31

can you rule out a cerebellar problem with a good pursuit?

Back 31

no

Front 32

a disruption in the connection b/t the vermis and fastigial nucleus causes? essencially th fastigial is working it just is not shutting off.

Back 32

opsoclonus - commonly caused by neuroblastoma in kids, viral encephalitis in young adults and metastatic cancer in older adults

Front 33

ipsiversive horizontal pursuit deficits ca be caused by a lesion where at in the cerebellum?

Back 33

vermis

Front 34

a patient has a problem making contraversive horizontal pursuits, where could they have a problem in the cerebellum?

Back 34

fastigial nucleus

Front 35

a lesion in the tract from the MVN on will cause problems not only with pursuits but what else?

Back 35

VOR since they share the same tract

Front 36

what is the first test you should perform to check a pts tracking ability?

Back 36

something like the nsuco or scco

Front 37

while doing the nsuco testing you see catch up saccades this means their gain is too low or high? what do you do?

Back 37

their gain is too low so you need to slow down.

Front 38

while doing the nsuco testing you see backup saccades. this means that their gain is too low or too high? what do you do?

Back 38

too high so you need to go faster.

Front 39

If a patient has a problem with gain they might also have a problem with what? (hint: going from the waiting room the your lane)

Back 39

they will likely have balance problems

Front 40

scco scoring is for pursuits, saccades, or VOR testing?

Back 40

pursuits

Front 41

in scco scoring what is more sever a 1 or a 4?

Back 41

1

Front 42

if you have a pt that has a difference in the left and right pursuit symmetry where could there be a possible problem?

Back 42

in one of the cerebral hemispheres

Front 43

after first testing a pts pursuit ability, the second thing you should test is what?

Back 43

OKN slow phases

Front 44

after testing pursuit ability and OKN slow phases what should you test third? and how

Back 44

VOR cancellation of pursuits by spinning the pt in the chair while fixating on their thumb

Front 45

while spinning a pt in the exam chair and having them fixate on their thumb, they should be able to maintain fixation due to what system? what is happening if you see corrective saccades?

Back 45

VOR. corrected saccades means that the VOR is being cancelled out properly.

Front 46

where would a lesion if a person is having difficulty making adducting movements during saccades, pursuits and VOR,with the right eye

Back 46

the MLF on the right side. (internuclear ophthalmoplegia)

Front 47

a pt has a conjugate horizontal saccadic palsy to the left where could the problem be

Back 47

in the left pprf

Front 48

horizontal gazed evoked nystagmus is associated with a lesion in what area?

Back 48

the NPH-MVN

Front 49

what nucleus could a lesion be in, in the pprf to cause slowing of saccades.

Back 49

rip

Front 50

the MLF and INC lesions affect what saccades, pursuits, VOR, or OKN?

Back 50

both saccades and pursuits

Front 51

a unilateral lesion to the riMLF causes slowing of what?

Back 51

downward saccades and loss of ipsitorsional saccades.

Front 52

a bilateral lesion to the riMLF causes what?

Back 52

vertical and torsional saccadic palsy in all directions

Front 53

the INC causes what

Back 53

torsional nystagmus with the quick phase going towards the lesion

Front 54

if a patient cannot generate a saccade the lesion is in what?

Back 54

the FEFsac and the SC

Front 55

saccades are slow and dysmetric the lesion is likely in the?

Back 55

dorsal vermis

Front 56

saccades are hypometric and delayed the lesion is likely in the?

Back 56

FEFsac OR SC

Front 57

classically if you have a pt with a cerebral lesion on the left side, describe saccadic and pursuit movements

Back 57

pursuits will have ipsiversional dysfunction and saccades will be hypometric away from the lesion.

Front 58

expect ratchet like saccades and general ataxia with what type of problem?

Back 58

spino-cerebellar atrophy.

Front 59

some one that has mobius syndrome will show what kinds of signs when it comes to pursuits?

Back 59

they will show big head movements

Front 60

both bilateral horizontal gaze palsy and mobius syndrome are or can be?

Back 60

genetic

Front 61

upward pursuits are affected by what?

Back 61

rostral NRTP

Front 62

lesions in the FEFsem, DLPN, NOT, and the vermis all cause what?

Back 62

ipsiversive horizontal pursuits