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Neuro Pt 3 > Brainstem Review > Flashcards

Flashcards in Brainstem Review Deck (36)
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1

Where does CN I exit the brainstem?

Telencephalon - Olfactory

2

Where does CN II exit the brainstem?

Diencephalon - Optic

3

Where does CN III exit the brainstem?

Midbrain - Occulomotor

4

Where does CN IV exit the brainstem?

Midbrain - Troclear

5

Where does CN V exit the brainstem?

Pons - Trigeminal

6

Where does CN VI exit the brainstem?

Pons - Abducens

7

Where does CN VII exit the brainstem?

Pons - Facial

8

Where does CN VIII exit the brainstem?

Pons/Medula - Vestibulocochlear

9

Where does CN IX exit the brainstem?

Medulla - Glossopharyngeal

10

Where does CN X exit the brainstem?

Medulla - Vagus

11

Where does CN XI exit the brainstem?

Medulla - Accessory

12

Where does CN XII exit the brainstem?

Medulla - Hypoglossus

13

How do you examine CN I?

History of head injury, smoking, URI, toxins/drugs. Ensure passages are open. Test nostrils separately with non-irritating stimuli.

14

How do you examine CN II?

VISUAL ACUITY - Snellen eye chart. VISUAL FIELDS - peripheral eye vision. DIRECT OPHTHALMOSCOPY - Red reflex, opacities, fundus (cup:disk ratio ~ 0.3). PUPILLARY EXAM - Size, reactivity, accommodation, swinging flashlight

15

How do you examine CN III?

Inspect gaze (eye movement), pupil, eyelid

16

How do you examine CN IV?

Superior oblique muscle depresses, intorts, and abducts the globe. Eye moves up when directed medially.

17

How do you examine CN V?

Corneal Blink reflex, Jaw jerk reflex, muscles of mastication, sensation on face

18

How do you examine CN VI?

Innervates the lateral rectus, which abducts the eye. Eye cannot move laterally past midpoint. Test with eye movements along CN III and CN IV.

19

How do you examine CN VII?

Corneal blink reflex (with V1). Test facial expressions and eye closing. Upper half of face is dually innervated (Left + right motor cortex). Lower half of face is innervated by contralateral motor cortex.

20

How do you examine CN VIII?

Weber test: tuning fork on top of skull. Is sound lateralized? Rinne test: tuning fork on mastoid process and then air. Normally air conduction > bone conduction. Vestibulocular reflex. Examine hearing and balance.

21

How do you examine CN IX?

Gag reflex. Also controls taste for posterior 1/3 of tongue.

22

How do you examine CN X?

Swallowing muscles

23

How do you examine CN XI?

Test strength of trapezius and SCM

24

How do you examine CN XII?

Check for tongue deviation. Deviation occurs in direction of the lesion.

25

What impairments may be detected in CN I?

Impairments may result from failure of odorants to reach olfactory mucosa or sensorineural deficits. Unilateral impairments are more often sensorineural, bilateral impairments are more often conductive.

26

What impairments may be detected in CN II?

PAPILLEDEMA - hyperemia that is caused by the dilation of the disk capillaries, swelling of axons in the peripapillary nerve fiber layer, which causes blurred disk margin, elevation of the disk, "red cell" shape, retinal nerve fiber layer hemorrhage. SYMPATHETIC DYSFUNCTION - aniscoria worse in dark (can't dilate). PARASYMPATHETIC DYSFUNCTION - aniscoria worse in light (can't contract) AFFERENT PUPILLARY DEFECT - swinging flashlight elicits constriction reflex from good eye, dilation from bad eye.

27

What impairments may be detected in CN III?

Ptosis, Down and out gaze, abnormal pupil.

28

What impairments may be detected in CN IV?

Pts report vertical, torsional, or oblique diplopia, usually worse on downgaze. Pts adopt characteristic head tilt. Affected eye tracks upwards when it moves medially.

29

What impairments may be detected in CN V?

Jaw deviates towards injured side. Hyperreflexia of jaw jerk.

30

What impairments may be detected in CN VI?

Cannot abduct affected eye