VN - Nystagmus - Week 11 Flashcards

1
Q

List 18 components of neurological testing in an optometric setting.

A
External exam
-proptosis, ptosis, lid retraction etc
VA with current Rx
Confrontation
-amsler + red cap
Ishihara CV
-monocular
Pupils including size
Oculomotility
Smooth pursuit
Saccades
-horizontal, vertical, oblique
Convergence
Cover test
Blood pressure/heart rate (automatic)
Fundus photo
OCT
VF (central/30-2)
-neuro setting possibly too long
CN testing
Mental testing
Sensory testing
Reflex testing
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2
Q

At what VA with Rx should you pinhole?

A

If worse than 6/9

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3
Q

Describe the measurement for the palpebral fissure aperture. Note the normal results and what is abnormal.

A

Distance between the upper and lower eyelids
Normal - 9 to 11mm
Abnormal <9mm

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4
Q

Describe the marginal reflex distances, what normal values are, and abnormal values (2).

A

Distance between the lids and the corneal reflex
Normal 4-5mm
Abnormal <4mm or 1.5mm asymmetry between MRD1/MRD2

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5
Q

Describe how levator function is taken, the normal value, and abnormal value (3).

A
Distance between excursion of upper lid margin from full down gaze to full up gaze without brow movement
Normal >10mm
Abnormal
-good 8 to 10mm
-moderate 5 to 7mm
-poor <4mm
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6
Q

Describe how the lid crease is assessed. Note the normal values in men and women, and what is abnormal (2).

A

Distance from the upper lid margin to the lid crease
Women - 10 to 11mm
Men - 8 to 9mm
If the lid crease is higher than normal or if there is a deeper upper lid sulcus

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7
Q

List four things that can be asked of the patient as part of mental screening.

A

Ask exact time (day/month/year)
Ask the patient to repeat three simple words. Ask them to repeat it in five minutes
Ask who our prime minister is
Ask a patient to spell a simple word forward and backword

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8
Q

List 5 components of cerebellar function testing.

A
Finger to nose test
Rapid alternating movements
-pat their thighs
Rombergs test
-stand straight, eyes closed
Dynamic rombergs test
-march on the spot, hands out
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9
Q

How do cerebellar lesions affect saccades and nystagmus? Which side is affected?

A

Same side as the lesion is affected
Saccades over/undershoot
Jerk nystagmus

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10
Q

Which way do patients tild their head with a superior oblique palsy?

A

Head tilt to the opposite side

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11
Q

List 6 optometric exams that assess CN2 function.

A
VA
VF
CV
Amsler
Pupils
ONH exam
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12
Q

List 2 optometric exams that assess CN3 function.

A

Pupils and oculomotility, including levator and lids

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13
Q

What does superior oblique palsy indicate (which CN)?

A

CN4

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14
Q

What two corneal nerves can corneal sensation indicate?

A

CN5 or 7

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15
Q

CN6 controls what eye muscle?

A

Lateral rectus

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16
Q

What can poor CN7 function result in?

A

Facial paralysis

-bells palsy

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17
Q

List 4 CN8 function tests that can be done in an optometric setting.

A
Finger rubbing test
Tuning fork test
-rinnes test
Head impulse test
Dix-hallpike test
-sit upright, rotate head
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18
Q

Describe rinnes test, including what the different test results mean (2).

A

Air conduction vs bone conduction (mastoid bone)
Sensori-neural loss vs conductive hearing loss
BC>AC indicates conductive loss (middle ear)
AC>BC indicates normal/sensori-neural loss (inner ear)

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19
Q

Describe how to assess the function of CN9 and 10.

A

Observe the uvula for any sideway deviations

Palate should rise symmetrically with little nasal air

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20
Q

Describe how to assess CN11 function.

A

Have the patient shrug their shoulders and turn their heads against resistance

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21
Q

Describe how to assess CN12 function.

A

Stick out tongue

-should be straight

22
Q

List 2 ways a patients sensory input can be assessed.

A

With closed eyes, have the patient tell between sharp and dull stimulation
Bend their big toe with their eyes closed, ask them which way it is bent

23
Q

Describe how dynamic VA is tested and what is vital to ensure proper testing.

A

Rotate head longer and see if there is any impact on VA
-no more than 1 line drop
Duration and speed are vital

24
Q

Describe what is meant by infantile nystagmus. Can it occur in later life?

A

An involuntary ocular motor oscillation that manifests at or shortly after birth
-rarely occurs later in life
It persists thoughout life

25
Q

What is infantile nystagmus associated with?

A

An underlying disorder of the visual system

26
Q

What percentage of individuals with infantile nystagmus will exhibit strabismus?

A

30%

27
Q

Describe wehther infantile nystagmus is uni- or bilateral, conjugate, and symmetrical in terrms of amplitude.

A

It is characteristically bilateral, conjugate and similar amplitude in both eyes

28
Q

Describe what happens to the severity/magnitude of infantile nystagmus with fixation effort, stress, and motivation.

A

It worsens with all three

29
Q

What happens to infantile nystagmus severity/magnitude with convergence? What about voluntary lid closure? What about sleep?

A

Dampens with convergence and lid closure

Abolished by sleep

30
Q

Describ what is meant by a foveation period in describing nystagmus.

A

Portion of the waveform of a nystagmus where the image of the point of regard is on or near the fovea and the eyes are stationary

31
Q

Can waveforms of infantile nystagmus change with age?

A

Yes

32
Q

Do waveforms of infantile nystagmus vary with different gaze directions?

A

Yes

33
Q

What is an important diagnostic indicator of infantile nystagmus regarding its oscillations?

A

It always remains horizontal, regardless of gaze position

34
Q

What is meant by the null zone?

A

Field of gaze in which nystagmus intensity is minimal and has the best foveation period

35
Q

What can the null zone lead patients to do?

A

Patients can exhibit a null zone laterally, so an abnormal head posture may be adopted to shift the eyes into the null zone
-minimises nystagmus intensity and maximises visual acuity

36
Q

List 5 questions you can ask if you suspect infantile nystagmus (workup).

A

Do you experience oscillopsia
Does it get worse when you are tired, sick, stressed etc
When you turn your head/face, to your preferred position, does it get better
Has the patient noticed anything unusual/different when they are reading/playing with toys
Has the teacher noticed any issues at school

37
Q

If you suspect infantile nystagmus, describe how you would assess VA and refraction.

A

Assess looking straight ahead, and again with preferred head posture
Check if there is a difference

38
Q

Describe how you would do cover test differently if you suspect infantile nystagmus and also note what you would look out for.

A

Perofrm slower than usual

Look for a change in nystagmus dirrection as you cover/uncover

39
Q

What should you look out for when doing oculomotility and you suspect infantile nystagmus?

A

Does the nystagmus change in different gaze positions with head straight
-is it always horizontal

40
Q

What should you look out for when doing convergence and you suspect infantile nystagmus?

A

Does it dampen with convergence

41
Q

Is eye movement recording essential for nystagmus or can you just skip it?

A

Essential

42
Q

List the four types of waveforms of nystagmus and note what they look like.

A
Pendular
-like a sine wave (sinusoidal)
Linear/constant velocity
-sawtooth/factory roof
Accelerating
-exponential curve followed by a cliff - repeating
Decelerating
-logarithmic curve followed by a cliff - repeating
43
Q

Is there a cure for infantile nystagmus?

A

No

44
Q

What kind of refractive error is associated with infantile nystagmus?

A

High with the rule astigmatism

45
Q

Describe how version prisms can aid individuals with infantile nystagmus.

A

In those with an eccentric null zone, it can help push the visual scene laterally and dampen the nystagmus

46
Q

Describe how vergence prisms can be used to help individuals with infantile nystagmus. Note a good starting approach.

A

Induces convergence to reduce nystagmus

An approach is to begin with 7 prism D BO in combination with -1.00DS to offset accommodation

47
Q

What is the most beneficial combination of therapy for infantile nystagmus (2)?

A

Surgery followed by combination prisms

48
Q

List two possible pharmacological interventions for infantile nystagmus. Describe a possibility of what may be occurring with these drugs.

A

Memantine
Gabapentin
-possible that INS reduction

49
Q

What is the principle aim of surgical management of infantile nystagmus (2)?

A

Moving the null zone to the primary gaze position to correct abnormal head tilts/turns
Also to broaden the null region and minimise nystagmus at all angles

50
Q

Describe the anderson-kestenbaum procedure for infantile nystagmus.

A

Recession of part of the pair of rectus muscles responsible for the direction of face turn or the antagonist muscles

51
Q

What is the mainstay of infantile nystagmus treatment?

A

Surgery