10-30 L3 Cranial nerves

Question 1

Olfactory hallucinations

Answer 1

damage to the primary cortical olfactory area in the temporal lobe (masses or seizures)

Question 2

Anosmia/hyposmia

Answer 2

Fractures of the floor of the anterior cranial fossa involving the cribriform plate
-CSF Rhinorrhea
tumors, abscesses, meniniomas: compression of olfactory bulb or tract

Question 3

Anomalous trichromatism

• protanomaly
• deuteranomaly
• tritanomaly

Answer 3

Anomalous trichromatism: defective color vision

• protanomaly: R cones abnormal
• deuteranomaly: G cones abnormal
• Tritanomaly: B cones abnormal

Question 4

Dichromatopsia

• protanopia
• deuteranopia
• tritanopia

Answer 4

dichromatopisa: defect in matching colors, b/c instead of 3 wavelengths you have 2.
- protanopia: R cones absent
- deuteranopia: G cones absent
- Tritanopia: B cones absent

Question 5

What’s the most common form of color blindness?

Answer 5

Anomalous trichromatism: deuteranomaly

Question 6

What is the path of the visual field from the upper half

Answer 6

Upper visual field–>lower retina–> loop of meyer–>lingual gyrus

Question 7

Damage to the visual system can be caused by?

Answer 7

defects in the development (anophthalmia, cyclopia)
vascular problems (diabetes, occlusion)
trauma to the face or head

Question 8

Anophthalmia

Answer 8

abscess of one or both eyes

Question 9

Cyclopia

Answer 9

failure of the embryonic prosencephalon to properly divide the eye in to two cavities.

Question 10

Papilledema

Answer 10

increased intracranial pressure

Question 11

Glaucoma

Answer 11

excessive intraocular pressure

Question 12

Cataract

Answer 12

loss of transparency of the lens

Question 13

Monocular blindness

Answer 13

damage to the optic nerve results in the loss of input from the ipsilateral eye only
-the pt. will complain of blindness in that eye.

Question 14

What happens to the visual field if the chiasm is compromised (pituitary tumor).

Answer 14

if the medial aspect of the chiasm is compromised decussating axons are affected leading to loss of visual input from the nasal hemiretinas in both eyes
(bitemporal hemianopsia)

Question 15

What happens to the visual field if the lateral aspect of the chiasm is damaged? (e.g. lesion due to an aneurysm)

Answer 15

Input from the temporal retinal half of the ipsilateral eye is lost, this results in loss of the ipsilateral nasal visual field.

Question 16

What happens to the visual field if a lesion of Meyer’s loop (anterior part of the temporal

Answer 16

results in a homonymous superior quadratic anopsia.

Question 17

What happens to the visual field when damage to the optic tracts, lateral geniculate nucleus, optic radiation, or visual cortex?

Answer 17

results in loss of input from the contralateral visual fields of both eyes.

Question 18

Any cortical lesion is going to have what distinctive feature?

Answer 18

Macular sparing

Question 19

Cochlear or spiral ganglion consists of cells located where?

Answer 19

In the spiral configuration at the periphery of the modiolus.

Question 20

Where does high and low freq occur in the cochlea?

Answer 20

high freq. (base of the cochlea)

low freq. (apex of the cochlea)

Question 21

Where will a lesion resulting in deafness occur?

Answer 21

a lesion up to and including the cochlear nuclei will result in deafness

Question 22

What happens when an interruption of the lateral lemniscus occurs?

Answer 22

decreased ability to localize sound

Question 23

Name the different types of conductive hearing loss (4-DODO)

Answer 23

Damage to the tympanic membrane
Occlusion of the auditory canal (cerumen impaction)
Disruption of the operation of the ossicular chain
Otitis media

Question 24

Cerumen impaction

Answer 24

wax in the ear

Question 25

Otitis media

Answer 25

an inflammation of the middle ear cleft

Question 26

Disruption of the operation of the ossicular chain (FOD)

Answer 26

• Fluid accumulation (Otitis media)
• Otosclerosis
• Disarticulation

Question 27

Name the different types of sensorineural hearing loss (2-DP)

Answer 27

• Disorders affecting the cochlea

- Problems in the transmission of information along the auditory pathways.

Question 28

Disorders affecting the cochlea (4- HOMP)

Answer 28

• Hydrops
• Ototoxis agents
• Meniere’s disease (fluid build up in the modiluosu)
• Presbycusis (getting old)

Question 29

Problems in transmission of information along the auditory pathways

Answer 29

lesions to cranial n VIII

Question 30

Review slide

What are the 3 tracks leaving the vestibular nuclei (counter rotation of the eye).

Answer 30

• abducens nucleus (6) opposite
• oculomotor nucleus (3) same
• abducens nucleus same side to go to (oculomotor nucleus opp, and LR same)

Question 31

Damage to the vestibular apparatus causes what?

Answer 31

• dizziness, falling to the side of the lesion, abnormal eye movements
• Benign paroxysmal vertigo (BPV)

Question 32

Acoustic neuroma (schwannoma)

Facial n component

Answer 32

weakness of muscles of facial expression
lost of taste (anterior 2/3 of the tongue)
Lack of stimulation of salivary, mucosal and lacrimal glands on affected side (7th n)

Question 33

Acoustic neuroma (schwannoma)

Vestibular component

Answer 33

dizziness, nausea, disorder of balance

Question 34

Acoustic neuroma (schwannoma)

cochlear component

Answer 34

tinnitus, ipsilateral deafness

Question 35

Meinere’s disease (SAUL)

Answer 35

• Severe vertigo, vomiting, ataxia
• Auditory and vestibular symptoms
• Unilateral deafness and tinnitus
• Lesion affecting the production of the endolymph

Question 36

Motion sickness (Kinetosis)

Answer 36

• occurs when there is discrepancy between vestibular and visual inputs
• Symptoms include dizziness, vomiting, sweating

Question 37

Acute alcohol intoxication

Answer 37

Alcohol infiltrates the cupulae

results in illusions of movement in response to certain orientations of the head.

Question 38

Which of the CN are SA?

Answer 38

CN II, III, VII (2/3 anterior taste), VIII (balance, hearing), IX (taste around the epiglottis)