eye mvmt disorders

Question 1

What are the 4 main categories of eye movement disorders?

Answer 1

1. binocular diplopia
2. diplopia sub type: INO
3. gaze palsy
4. nystagmus

Question 2

fusion is usually present, but the two eyes together cannot move into certain positions of gaze.

Answer 2

gaze palsy

Question 3

technically, a specific type of unsteady fixation, characterized by a slow movement (pursuit) in one direction followed by a rapid (saccadic) eye movement in the other direction. There are many varieties. Know that any inability to stay fixated is a problem.

Answer 3

nystagmus

Question 4

with both eyes open, the patient sees double some or all of the time. The implication is that when the patient reports diplopia, the eyes are out of alignment.

Answer 4

binocular diplopia

Question 5

“internuclear ophthalmoplegia,” a very specific type of EOM anomaly that may or may not be accompanied by diplopia in some positions of gaze.

Answer 5

diplopia sub type

Question 6

what is the final common pathway?

Answer 6

cranial nerves that control the muscles

Question 7

what do the pre motor nuclei organize?

Answer 7

eye movements by coordinating the nuclei that control the muscles

Question 8

what do supranuclear structures do?

Answer 8

control the nuclei

Question 9

what do systems do?

Answer 9

maintain fixation

Question 10

what are the supranuclear levels split up into?

Answer 10

cortical and subcortical

Question 11

what are the 3 supranuclear levels?

Answer 11

saccades
pursuits
OKN

Question 12

whats in the premotor level

Answer 12

premotor nuclei: riMLF and PPRF

vestibular nuclei

Question 13

what level is VOR in?

Answer 13

subcortical

Question 14

list the levels from premotor level to final common pathway

Answer 14

premotor nuclei
internuclear
nuclear level
external level

Question 15

whats in the nuclear level?

Answer 15

CN 3
CN 4
CN 6

Question 16

what does the nuclear level lead to?

Answer 16

external level

Question 17

how many EOMs are there?

Answer 17

12

Question 18

where are the 3 locations of pathology of the EOMS?

Answer 18

1. in a muscle/muscles
2. in a synapse (b/w a nerve ending and a muscle)
   3 in the orbit

Question 19

where are the 3 locations of pathology of a nerve that controls EOMs?

Answer 19

1. in the brainstem nucleus
2. in the brainstem where axons traverse the brain (interstitial)
3. in the space from the exit of the axons from the brain to the muscle

Question 20

where are the 4 locations of pathology of premotor structures that control the nerve nuclei that controls EOMs?

Answer 20

1. PPRF
2. riMLF
3. vestibular nuclei, CN 8
4. MLF (Internuclear)

Question 21

Where are the 4 locations of pathology of structures that control the nuclei and EOMs to maintain fixation (premotor)?

Answer 21

1. semicircular canals
2. CN 8
3. vestibular nuclei
4. cerebellum (flocculondular lobes)

Question 22

Where are the 3 locations of pathology of higher order (supranuclear) structures that control –> the premotor structures that control –> the nerve nuclei that controls –> the nerve that controls EOMS?

Answer 22

1. superior colliculus
2. frontal eye fields (scans)
3. occipital eye fields (pursuits)

Question 23

If patient presents with diplopia, where are the 5 locations of pathology?

Answer 23

1. orbit
2. EOM
3. Synapse
4. nucleus
5. nerve

Question 24

If patient presents with INO, where is the location of pathology?

Answer 24

premotor structures

Question 25

If patient presents with gaze palsy, where is the location of pathology?

Answer 25

supranuclear structures

Question 26

If patient presents with nystagmus, where is the location of pathology?

Answer 26

vestibular system, CN 8

Question 27

Why is it clinically relevant to know your neurological anatomy?

Answer 27

Neuropathology strikes specific locations and affects ALL systems with parts that are present in that location.

Question 28

associated signs/ symptoms of orbit

Answer 28

Space-occupying, CN5

Question 29

system structures present in orbit

Answer 29

``` EOMS nerves fat fascia connective tissue ```

Question 30

associated signs/symptoms of orbital apex

Answer 30

space occupying lesion | CN 2

Question 31

system structures present in orbital apex

Answer 31

superior orbital fissure | optic canal

Question 32

associated signs/ symptoms of nerve

Answer 32

aneurysm space occupying lesion inflammation

Question 33

system structures present in nerve

Answer 33

``` subarachnoid space circle of willis cavernous sinus superior orbital fissure posterior orbit ```

Question 34

associated signs/symptoms of nerve nucleus and interstitial axons (midbrain)

Answer 34

CONTRALATERAL voluntary somatic movement | incoordination

Question 35

system structures present in nerve nucleus & interstitial axons (midbrain)

Answer 35

``` descending pyramidal system rostral to decussation red nucleus (motor system) ```

Question 36

associated signs/symptoms nerve nucleus and interstitial axons (pons)

Answer 36

``` contralateral voluntary somatic movement incoordination dysmetria imbalance dizziness ```

Question 37

system structures present in nerve nucleus and interstitial axons (pons)

Answer 37

Descending pyramidal system rostral to the decussation, vestibular nuclei, cerebellum is nearby

Question 38

associated signs/symptoms related to premotor (brainstem)

Answer 38

incoordination dysmetria imbalance dizziness

Question 39

system structures present with premotor (brainstem)

Answer 39

MLF, SC, vestibular system, cerebellum

Question 40

associated signs/ symptoms of premotor (supranuclear)

Answer 40

Aphasia, psychological, VF defects

Question 41

system structures present with premotor (supranuclear)

Answer 41

Frontal & occipital lobes

Question 42

associated signs and symptoms of vestibular system (CN 8)

Answer 42

Contralateral voluntary somatic movement, facial asymmetry, reduced auditory sensitivity

Question 43

system structures present in vestibular system (CN 8)

Answer 43

Facial nerve (CN7), auditory system, descending pyramidal system rostral to decussation

Question 44

3 things to look for under INO in EOM checklist

Answer 44

1. incomitant exo to L and/or R 2. unilateral end point nystagmus 3. convergence intact

Question 45

signs of elevated ICP

Answer 45

1. spontaneous venous pulsation 2. disc edema 3. CN 6 dysfunction