(45) Vertigo

Question 1

the saccade = fast or slow component of nystagmus

Answer 1

fast

Question 2

if the nystgmus in to the right, which direction is the slow component? what direction would the individual perceive the room to be spinning?

Answer 2

slow phase = left so room spins from left to right

**recall, you only can process visual info in slow phase bc fast is too quick and you just see a blur/blinded

Question 3

a right beating nystagmus indicates a dysfunction in what side of the vestibular system?

Answer 3

left vestibular

Question 4

rotation about the y axis is called

Answer 4

pitch

**movement like slow pitch softball

Question 5

rotation about the X axis

Answer 5

yaw

Question 6

rotation about the x axis

Answer 6

roll

Question 7

structures that detect linear accelerations within a plane

Answer 7

utricle = horizontal
sacculus = vertical

Question 8

structures that detect rotational acceleration or deceleration

Answer 8

ampulla with 3 semicircular canals

Question 9

which structure of the vestibualr system in in parallel with the ground when standing

Answer 9

utricle

Question 10

how does distortion of hair cell lead to an electrical signal?

Answer 10

distortion opens K+ channel–> K+ in and depolarizes cell –> voltage gated Ca channels open –> influx of Ca signals release of glu/asp –> active afferent half of bipolar cells in scarpas ganglia –> efferent half of biolar cells go to brainstem as vestibular nerve

**reversed bc influx of Ca acitvates K+ efflux pumps

Question 11

in the ____ the kinocillia are directed away from the striola and in the ____ are directed toward the striola

Answer 11

away = sacculus
toward = uricle

Question 12

if you jerk head to the left and you want your eyes to remain in the middle which sides of the vesitbular system will be activated or inhibited?

Answer 12

left active and right inhibited semicircular canals

Question 13

what is the VOR?

Answer 13

vestibular ocular reflex. keeps eyes midline when jerk head to side

Question 14

which semicircular canal is likely to become obstructed by otoliths?

Answer 14

posterior

Question 15

slow phase nystagmus is (away from or towards) the side of the lesion

Answer 15

towards

Question 16

explain the results of ice calorics in a person in a true coma (but still has intact brain stem)

Answer 16

eyes will look in the direction of the ear that was irrigated (i.e. irrigate left ear and eyes will look right) this is bc you KO left vestubualr system so the right takes over and pushes eyes to left

Question 17

explain the results of ice calorics in a person in a pshycogenic coma (but still has intact brain stem)

Answer 17

will get fast saccades (nystagmus) towards the opposite side of the irrigation /away from irrigated side

COWS

Question 18

purpose of using frenzel lenses

Answer 18

eliminate visual fixation to reveal compensated nystagmus

Question 19

head shaking maneruver with left beading nystamus = lesion on what side of the vestibule system

Answer 19

left

Question 20

to perform the Dix maneuver and maximally simulate the left posterior canal, how would you have to position the head when you lie the person back?

Answer 20

turn the head to the left

Question 21

eye movements expected with dix hallpike when right posterior canal is affected by BPPV

Answer 21

upbeat (when looking left)

Question 22

a person with vestibular neuritis will have gait that causes the person to walk (towards or away from) the affected ear

Answer 22

towards

Question 23

how can person receive temporary relief from vestibular neuritis

Answer 23

ice calorics in UNAFFECTED ear