Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

VMCVM SAM 2 > Vestibular Diseases > Flashcards

Vestibular Diseases Flashcards

1
Q

What is the main function of the vestibular system?

A
  1. maintain balance
  2. maintain position of the eyes, neck, limbs and trunk relative to the position or motion of the head

deviations in the vestibular system will affect these functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What bone is the peripheral vestibular system in?

A

petrous temporal bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is bony labyrinth filled with?

A

Perilymph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the membranous labyrinth filled with?

A

Endolymph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Nystagmus fast phase is toward the Normal or Diseased side?

A

Fast Phase toward NORMAL side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Crista ampullaris is important for what kind of equilibrium?

A

Dynamic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Maculae and saccule are important for what kind of equilibrium?

A

Static

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Peripheral Vestib. head tilt

A

side of lesion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Central vestib head tilt

A

usually toward side of lesion but can be paradoxical and go other side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Peripheral vestib nystagmus

A

horizontal or rotary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Central vestib nystagmus

A
  • vertical* is always central

* positional* and changing from any of them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Peripheral vestib postural reactions

A

no deficits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Central vestib postural reactions

A

on side of lesion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

CN Deficits peripheral vestib

A

ipsilateral +/- CN 7 since they run together peripherally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

CN deficits central vestib

A

ispsilateral CN 5-8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Can Horner’s be present in either peripheral or central?

A

yes

17
Q

Consciousness affected by peripheral or central vestib?

A

not peripheral

central can be normal to comatose

18
Q

If an animal looks funky and is making WIDE HEAD movements what does that indicate?

A

they cannot move their eyes, can be two things

  1. bilateral peripheral vestib dz
  2. blind

CANNOT BE CENTRAL, animal would be comatose if there was a bilateral central lesion in the medulla

19
Q

With Paradoxical Central Vestib. Dz, what side is the lesion on?

A

side of the postural reaction deficits

20
Q

How can you tell from a distance if disease is central or peripheral?

A

Head tilt, nystagmus, or vestibular ataxia

21
Q

How do you pursue diagnostics once you discern the lesion is central?

A

CBC/Chem/UA/T4/BP then follow up with MRI if that’s not definitive enough

22
Q

How do you pursue diagnostics once you discern the lesion is peripheral?

A

straight to the Otoscopic exam**
if normal –> Tympanic Bullae imaging Rads/US/CT/MRI
if abnormal –> Fluid cytology or mass aspirate

If normal and imaging normal –> Thyroid profile

23
Q

Peripheral vestibular diseases DDX

A

Anomalous: congenital disease
Metabolic: Hypothyroid dog
Neoplastic: 1˚ Aural, Nerve Sheath or Osteosarcoma
Inflammatory: Otitis Media Interna, nasopharyngeal polyp, idiopathic
Toxic: drugs, almost everything is toxic but don’t realy get that bad of responses to most things

24
Q

What would make you think Anomalous peripheral vestib. dz?

A

Age: young
Malformation or early onset abiotrophy

No therapy

25
Q

What would make you think Metabolic peripheral vestib. dz?

A

Other clinical signs of hypothyroidism:
- alopecia, loss of hair, obtunded and dull look/mentation

Pathophys: Myxomatous compression of nerves, dec. inner ear perfusion, axonal transport defects

Dx: T4 fT4, TSH

Tx: Levothyroxine supplement (give thyroid hormone/analog)
- Will improve in days to months

26
Q

What would make you think of Neoplastic peripheral vestib. dz?

A

Mass in the ear
DX: mass in ear and evidence of bony lysis/infiltration on imaging
TX: Sx is primary therapy; +/- radiotherapy; if lymphoma chemo +/- radio

27
Q

Cat or dog more concerning to have aural tumor?

A

Cats are 85% malignant - SCC

Dogs only 60% malignant - carcinoma

28
Q

What would make you think inflammatory cause of peripheral vestib. dz?

A

Head-shaking, pawing at ear, exudate, redness, pain at ear
bulging, opaque tympanic membrane
concurrent facial paresis

TX: Anesthesia, deep cleaning and Systemic antibiotics based on C/S
- get all underlying factors under control

29
Q

What would make you think idiopathic cause of peripheral vestib. dz?

A

Old dog - 12y and up, rarely in dogs < 5yo
Any age of cats can be affected though, more common in outdoor and late summer, early fall

DX: rule out other causes
TX: supportive care and physical therapy, clinical improvement in 2 weeks, head tilt may remain

30
Q

What are the main culprits of Central Vestib Dz?

A

Meningoencephalitis, neoplasia and Stroke account for 80% of central vestib dz. in Adult Dogs

recognition of central dz is grounds for immediate advanced imaging

31
Q

How many peripheral vestib cases have OMI?

A

50%

32
Q

How many chronic cases of otitis Externa have OMI?

A

50%

33
Q

How many OMI cases have otitis Externa?

A

80%

34
Q

DDX of central vestib dz:

A

Metabolic: Hypothyroidism
Neoplastic: Meningioma, Choroid plexus tumor, glioma
Inflammatory: Meningoencephalitis (Distemper, FIP, Protozoal, RMSF); otogenic infections, Granulomatous Meningoencephalitis
Toxic: Metronidazole
Vascular: Infarcts, Transient ischemic attacks

35
Q

What would make you think metabolic cause of central vestib?

A

accompanying signs of hypothyroidism

36
Q

What would make you think neoplastic cause of central vestib?

A

focal central lesion neurolocalization and evidence on CT/MRI

37
Q

What would make you suspect toxic cause of central vestib?

A

History of metronidazole
TX: stop drug (improve 4-12 days); give antidote if necessary Diazepam (improvement 12-48 hr)

Rule out metronidazole tox by giving diazepam and seeing if central vestib signs go away

38
Q

What is a transient ischemic attack?

A

Lasts less than 24 hours by definition. caused by vasospasm or stenosis

To rule out screen for strokes: hypertension, atherosclerosis, and coagulopathies

39
Q

What is pathophys of hypothyroidism causing central/peripheral acute/chronic vestib signs?

A
  • atherosclerotic cerebrovascular disease – predisposes to stroke
  • dec. axonal transport in brainstem white matter

VMCVM SAM 2 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions