Vestibular Disease

Question 1

Where is the vestibular apparatus located?

Answer 1

Inner ear (part of temporal bone)

Question 2

What comprises the vestibular apparatus?

Answer 2

Cochlea, semicircular canals, vestibule

Question 3

Which CN provides vestibular neurons?

Answer 3

Vestibulocochlear nerve (CN 8)

Question 4

Where does CN 8 enter the skull?

Answer 4

Internal acoustic meatus

Question 5

Where does CN 8 terminate?

Answer 5

Lateral wall of 4th ventricle

Question 6

The efferent pathway of the vestibulospinal tract inhibits what?

Answer 6

Ipsilateral flexor and contralateral extensor muscles

Question 7

What are clinical signs of peripheral vestibular system disease?

Answer 7

Head tilt, circling, horizontal/rotary nystagmus, facial nerve paralysis or Horner’s syndrome

Question 8

Which way will a head tilt or circling be with peripheral vestibular disease?

Answer 8

Toward the side of the lesion

Question 9

With pathologic nystagmus, which direction will fast phase be?

Answer 9

Away from the side of the lesion

Question 10

Though rare in animals, what is the main clinical sign of bilateral peripheral vestibular system disease?

Answer 10

Wide crouching stance w/wide swaying of the head

Question 11

Can you determine the side of the lesion with central vestibular system disease?

Answer 11

No

Question 12

With central vestibular disease, conscious proprioceptive deficits or hemiparesis can be seen on which side of the lesion?

Answer 12

Same side

Question 13

What are clinical signs of Horner’s syndrome?

Answer 13

Miosis, ptosis, enophthalmos

Question 14

Does Horner’s syndrome indicate central or peripheral vestibular disease?

Answer 14

Peripheral

Question 15

Conscious proprioceptive deficits indicate a lesion in which region of the CNS?

Answer 15

Brainstem

Question 16

Does multiple cranial nerve deficits usually indicate central or peripheral vestibular disease?

Answer 16

Central

Question 17

The presence of a head tremor indicates _____ disease

Answer 17

Cerebellar

Question 18

Does altered mentation indicate central or peripheral nervous disease?

Answer 18

Central

Question 19

What type of lesions typically cause spontaneous nystagmus w/horizontal and rotational components?

Answer 19

Acute peripheral lesions

Question 20

What type of lesions can cause purely vertical, horizontal, or rotational nystagmus?

Answer 20

Central lesions

Question 21

What ancillary tests can be done once you localize a lesion to the peripheral nervous system?

Answer 21

Otoscopic exam, typmanic bulla rads, thyroid test, BAER/CT

Question 22

What ancillary tests can be done once you localize a lesion to the central nervous system?

Answer 22

CT/MRI, CSF analysis

Question 23

Which disease is often peracute without apparent cause and will start to improve within several days w/o tx?

Answer 23

Idiopathic vestibular syndrome

Question 24

What clinical sign of idiopathic vestibular syndrome doesn’t usually resolve completely?

Answer 24

Head tilt

Question 25

How do you dx idiopathic vestibular syndrome?

Answer 25

Dx of exclusion

Question 26

What is a very common cause of vestibular disease in most species?

Answer 26

Otitis media and interna

Question 27

What is otitis media/interna commonly treated with?

Answer 27

Enrofloxacin

Question 28

How long should abx therapy to treat otitis continue?

Answer 28

Up to 8wk

Question 29

What abx is contraindicated for otitis?

Answer 29

Aminoglycosides

Question 30

How do you treat otitis media/interna that is refractory to medical therapy?

Answer 30

TECA-BO

Question 31

What is the most common substance implicated in ototoxicity?

Answer 31

Chlorhexadine

Question 32

What abx can cause ototoxicity?

Answer 32

Aminoglycosides

Question 33

Where do nasopharyngeal polyps most commonly appear in cats?

Answer 33

In the typanic cavity

Question 34

How does hypothyroidism cause vestibular disease?

Answer 34

Polyneuropathy with vestibular signs

Question 35

How can a tumor cause central vestibular signs?

Answer 35

Cerebella-pontine angle, brainstem compression, brain herniation

Question 36

Which abx toxicity can cause central vestibular system disease?

Answer 36

Metronidazole >30mg/kg/day

Question 37

How does Metronidazole toxicity often present?

Answer 37

Acute onset, even in patients with chronic treatment

Question 38

Often vestibular w/other CNS signs as part of multifocal brain disease

Answer 38

Inflammatory brain disease

Question 39

Generally sudden onset that may be idiopathic or 2* to hypertension, neoplasia, endocrinopathies, or sepsis

Answer 39

Cerebrovascular disease

Question 40

Most commonly occurs from overcooked meat diets or all fish diets

Answer 40

Thiamine deficiency

Question 41

Three ducts at right angles to each other and each filled w/perilymph

Answer 41

Semicircular ducts

Question 42

What turns perilymph movement into nerve conduction?

Answer 42

Ampulla

Question 43

What are the macula of the inner ear?

Answer 43

Utriculus and sacculus

Question 44

What do macula do?

Answer 44

Detect movement in the dorsal and sagittal planes

Question 45

What do the ampulla do?

Answer 45

Detects angular movement and acceleration

Question 46

Where in the brainstem does the central vestibular apparatus live?

Answer 46

Cranial aspect of medulla

Question 47

What are signs of vestibular ataxia?

Answer 47

Circling, leaning, falling, rolling

Question 48

CP deficits, vertical or changing nystagmus, CN signs other than Horner's and facial nerve paralysis are associated with which type of vestibular disease?

Answer 48

Central

Question 49

Ear polyps are relatively common in young _____

Answer 49

Cats

Question 50

Are inflammatory causes of central vestibular disease more common in cats or dogs?

Answer 50

Dogs (granulomatous meningioencephalitis and necrotizing encephalitis - aka sterile inflammatory dz)

Question 51

What are the most common causes of infectious central vestibular disease in cats?

Answer 51

FIP, cryptococcus, toxoplasmosis

Question 52

What is the most common toxic cause of central vestibular disease?

Answer 52

Metronidazole

Question 53

What is in fish that causes a thiamine deficiency?

Answer 53

Thiaminase

Question 54

With central vestibular disease, what type of nystagmus will you have?

Answer 54

Vertical

Question 55

Conscious proprioceptive deficits are assoc. w/which type of vestibular disease?

Answer 55

Central

Question 56

Head tilt, nystagmus, and circling will be in which direction with respect to the lesion?

Answer 56

Toward the lesion

Question 57

With paradoxical vestibular disease, which direction will clinicals signs be w/respect to the lesion?

Answer 57

Away from the lesion

Question 58

If you see peripheral signs in one direction but central signs in the other, where is the lesion?

Answer 58

Lesion is on side of central deficits

Question 59

When a lesion causes vestibular signs and CP deficits, where is the lesion?

Answer 59

Same side as CP deficits