Ocular Oscillations

Question 1

Who is separated and not separated by Intersaccadic intervals?

Answer 1

Yes ISI: Square wave jerks

NO ISI: Ocular flutter

Question 2

What is the waveform for OKN?

Answer 2

Saw-tooth

Has a linear slow phase velocity

Question 3

What causes the nystagmus in OKN?

Answer 3

The motion of the visual scene.

Mediated by retinal slip.

Question 4

Is end point nystagmus always present?

Answer 4

Nope (45% of ppl)

Question 5

What is jerk nystagmus?

Answer 5

Underneath EPN
Fast phase toward target in lateral gaze
Slow phase pulls the eye back to the center of the orbit

Question 6

When does nystagmus diminish over time?

Answer 6

Both rebound and EPN

Question 7

Is rebound nystagmus greater in the light or the dark?

Answer 7

The dark

Question 8

Oscillopsia is present in?

Answer 8

Acquired RN
Not present in INS.
Infantile PAN is rare
Acquired PAN has it

Question 9

What are the three congential ocular oscillations

Answer 9

Latent nystagmus
Spasmus nutans
Infantile nystagmus syndrome

Question 10

Which ocular oscillations are conjugate?

Answer 10

Latent nystgamus
Infantile nystagmus syndrome
SN is disconjugate

Question 11

Is latent nystagmus always associated with strabismus?

Answer 11

YES!

Question 12

In LN, is nystagmus enhanced or reduced when the eye is covered?

Answer 12

ENHANCED.

Question 13

Tell me about Alexander’s law?

Answer 13

Nystagmus is greatest when looking in the direction of the quick phase.
Pts turn their head to keep viewing eye in an adducted position because nystagmus is minimal.

Question 14

Which occurs first, congenital nystagmus or Spatmus nutans in terms of onset?

Answer 14

Congential nystagmus (0-4 months)
SN (4-18 months)

Question 15

Does Spatmus nutans stop at all in someone’s life?

Answer 15

Yes, it stops in middle infancy (age 3)

Question 16

Is there headshaking involved in SN?

Answer 16

Yes

Torticollis

Question 17

Tell me about the jerk waveform of INS?

Answer 17

The slow eye movement takes the eye off the target.

The fast eye movement brings the eyey back to the target.

Question 18

What is the key to diagnosis for INS?

Answer 18

An accelerating slow phase.

Question 19

Is pursuit always broken in INS?

Answer 19

YES

Question 20

Can the OKN be reversed in INS?

Answer 20

Yes

Question 21

What is a cycle of PAN.

Answer 21

Periodic alternating nystagmus:
left beating nystagmus
transition phase
right-beating nystagmus
transition phase

Question 22

What does AHP stand for?

Answer 22

Anomalous head posture

Question 23

What is the significance of AHP?

Answer 23

When a patient has this, means they for sure have periodic laternating nystagmus.

Question 24

Can a patient with PAN have more than one AHP?

Answer 24

NOPE.

They only have one.

Question 25

What is the length and symmetry of PAN?

Answer 25

4-5 minutes

Assymetric.

Question 26

PAN is a sub-category of…..

Answer 26

Infantile nystagmus

Question 27

INS can be both idiopathic and congenital…

Answer 27

Claro que si

Question 28

CHaracteristics of acquired PAN

Answer 28

Spontaneous
Horizontal
Present in primary gaze
Fast phase reverses direction every two minutes

Question 29

Baclofen

Answer 29

a drug that relaxes the eye muscles

Question 30

What is an ophthalmoscopic examination useful for?

Answer 30

Small eye movements

Question 31

What are some conservative trt for Anomalous head posture?

Answer 31

Auditory biofeedback

Use of prisms

Question 32

What is required for surgery of anomalous head posture?

Answer 32

Specific, constant, stable AHP

Question 33

What are the types of surgery?

Answer 33

Kestenbaum/Anderson
Four muscle recession
Tenotomy

Question 34

What are the drug trt for CN?

Answer 34

Memantine

Gabapentine

Question 35

What are the effects of the drugs used to trt CN?

Answer 35

Improve VA
Reduce nystagmus intensity
Improve foveation in congenital nystagmus

Question 36

What is a required speed for good VA?

Answer 36

Less than 4 degrees/ sec