Highlights chapter 12 pt 1

Question 1

What is the vestibular system? What does it do?

Answer 1

Sensory system that senses balance and spatial orientation coordinating movement with balance

Question 2

What are the two parts of the labyrinth of the inner ear?

Answer 2

1) Bony labyrinth
2) Membranous labyrinth.

Question 3

The bony labyrinth is filled with ________ called ______

Answer 3

fluid; perilymph

Question 4

1) What makes up the membranous labyrinth?
2) Where is it?
3) What is the membranous labyrinth filled with?

Answer 4

1) The cochlear duct, utricle, saccule and semicircular canals
2) Suspended in the perilymph.
3) Filled with endolymph.

Question 5

The maculae consist of ___________ called ________ sitting in a gelatinous layer where mechanoreceptor hair cells are embedded

Answer 5

calcified crystals; otoliths

Question 6

Primary vestibular neurons in the vestibular ganglia convey information about what?

Answer 6

Angular and linear acceleration

Question 7

1) The lateral vestibular nucleus gives rise to what?
2) What two things is this important in?

Answer 7

1) The lateral vestibulospinal tract
2) Maintaining balance and extensor tone.

Question 8

1) Where is the MVT (medial vestibulospinal tract) found?
2) What is it important in?

Answer 8

1) Extends only to the cervical spine
2) Important in controlling head and neck position

Question 9

What is an important job of the medial longitudinal fasciculus (MLF)?

Answer 9

Conjugates the gaze

Question 10

Define vertigo

Answer 10

Spinning sensation

Question 11

1) Most vertigo cases are caused by what?
2) What is a less common cause of vertigo?

Answer 11

1) Peripheral disorders involving the inner ear (usually benign.)
2) Central disorders of the brainstem or cerebellum are less common (usually urgent.)

Question 12

Dix-Hallpike testing can help differentiate between what?

Answer 12

Central or peripheral causes of vertigo

Question 13

1) What does the Dix-Hallpike test look like if the patient has peripheral lesions of the inner ear?
2) What does the nystagmus look like?

Answer 13

1) 2-5 second delay [in vertigo and nystagmus]
2) The nystagmus is horizontal or rotary and does not change directions

Question 14

1) What does the Dix-Hallpike test look like if the patient has central lesions of the inner ear?
2) What does the nystagmus look like?
3) Is there adaptation if it’s repeated?

Answer 14

1) Nystagmus and vertigo may begin immediately in supine position
2) Vertical nystagmus, nystagmus that changes directions while the patient is in the same position or prominent nystagmus in the absence of vertigo are only seen with central lesions.
3) No adaptation

Question 15

1) What is the most common cause of vertigo?
2) How long does it last?
3) When does it happen?

Answer 15

1) Benign paroxysmal positional vertigo (BPPV)
2) Brief episodes of vertigo lasting for a few seconds
3) Occur with change of position

Question 16

1) With Benign paroxysmal positional vertigo (BPPV), what helps the dizziness?
2) What is usually the cause?

Answer 16

1) If the patient remains still, the dizziness usually abates.
2) Otolithic debris in the semicircular canals

Question 17

1) What characterizes Meniere’s disease?
2) What is the etiology?

Answer 17

1) Recurrent episodes of vertigo with progressive hearing loss and tinnitus
2) Excess fluid (and pressure in endolymphatic system)

Question 18

1) Besides Meniere’s, what can cause cause hearing loss and tinnitus with associated dizziness?
2) How is it different? (3 things)

Answer 18

1) Acoustic neuroma
2) Causes unsteadiness, it’s not true vertigo, and does not have discrete episodes.

Question 19

Name two common causes of central vertigo

Answer 19

1) Vertebrobasilar ischemia or infarct
2) Small hemorrhage in cerebellum or brainstem

Question 20

What can gentamicin cause?

Answer 20

Bilateral vestibular dysfunction (and dizziness)

Question 21

1) What is the second most common cause of vertigo?
2) What is its suspected origin?
3) Who does it affect?
4) Is hearing impaired?

Answer 21

1) Vestibular neuritis
2) Viral origin
3) 30 to 50 years of age; men and women are affected equally
4) Not impaired

Question 22

What are the 3 angular axes that semicircular canals use to detect angular acceleration?

Answer 22

1) Anterior
2) Posterior
3) Horizontal (lateral)

Question 23

Name 3 essential roles of the vestibular nuclei

Answer 23

1) Adjustment of posture
2) Muscle tone
3) Eye position in response to movements of the head in space.

Question 24

Where are vestibular nuclei found?

Answer 24

Brainstem

Question 25

Semicircular canals convey information about ______ acceleration, while otolith organs convey information about ________ acceleration.

Answer 25

angular; linear

Question 26

What tract is important in maintaining balance and extensor tone, and extends the entire length of the spinal cord?

Answer 26

Lateral vestibulospinal tract

Question 27

List 2 nuclei that contribute to the medial vestibulospinal tract (important in controlling head + neck position; extends only to the cervical spine).

Answer 27

Medial vestibulospinal nucleus and Inferior vestibulospinal nucleus

Question 28

What part of the vestibular system conjugates the gaze?

Answer 28

Medial longitudinal fasciculus (MLF)

Question 29

Name a positive sign that could mean that a patient possibly has a problem outside of their vestibular system

Answer 29

Orthostatic hypotension

Question 30

An adaptable horizontal or rotary nystagmus is indicative of what?

Answer 30

Peripheral lesions of the inner ear

Question 31

In which vestibular condition does a change in position cause vertigo due to otolithic debris in the semicircular canals?

Answer 31

Benign paroxysmal positional vertigo

Question 32

A patient complaining of a full feeling in the ear, ringing of the ears and hearing loss over time that accompanies recurrent episodes of vertigo. What would be your diagnosis?

Answer 32

Meniere’s disease

Question 33

True or false: acoustic neuromas cause true vertigo

Answer 33

False

Question 34

Vestibular neuritis is the ____most common cause of vertigo while Benign paroxysmal positional vertigo is the ____ most common cause of vertigo.

Answer 34

2nd; 1st

Question 35

Name 2 common causes of central vertigo

Answer 35

1) Vertebrobasilar ischemia or infarct
2) Small hemorrhage in cerebellum or brainstem

Question 36

Gentamicin is ototoxic and causes ____________ vestibular dysfunction

Answer 36

bilateral