Vestibular system

Question 1

What are the 3 components that make up the anatomy of the vestibular system?

Answer 1

1. Peripheral sensory apparatus
2. Central processor
3. Motor neurons - VOR, vestibulocollic reflex, and vestibulospinal reflex

Question 2

What cranial nerve makes up the peripheral sensory apparatus?

Answer 2

8th

- vestibulocochlear nerve transmits uno from inner ear to brain

Question 3

Vestibular nuclei project information to the spine by way of the lateral and medial vestibular tracts and the reticulospinal tract; Cerebellum assists in maintaining balance, vision, and motor learning

Answer 3

central processor

Question 4

The ___ senses horizontal orientation and the ___ senses vertical orientation.

Answer 4

Utricle; saccule

• Sensory receptor for each of these is called the Macula
• otoliths

Question 5

Perceive linear acceleration in all three planes, and static tilt (acceleration of motion and position)

Answer 5

otoliths

Question 6

Three canals that are oriented at 90 degree angles from each other; Arranged in coplanar pairs, which results in a push / pull system; Push pull mechanism refers to the balance of vestibular information that is being sent to the brainstem by the canals; Detect angular acceleration of the head (velocity)

Answer 6

semicircular canals

• The primary sensory unit is the cupula
• The cupula is attached all the way around, and is deflected in response to a change of direction

Question 7

Tonic firing rate: at rest, the nerve fires at approximately ___ spikes per second, and goes up or down in response to movement

Answer 7

90

• Produces feeling of spinning if there is a mismatch in firing rate
• Brain will take a few days to accommodate and shut it down

Question 8

sensation of spinning (you or room)

Answer 8

vertigo

Question 9

What are primary symptoms of vestibular pathology? secondary?

Answer 9

Primary – loss of balance towards side of lesion, nystagmus, “eyes don’t keep up with my head”
- dizziness, vertigo, decreased postural control, dysequilibrium, nausea and vomiting, gait ataxia, sensitivity to head movements, sensitivity to head positions, sensitivity to visual motion, oscillopsia

Secondary - Fatigue, nausea/vomiting, headache, anxiety, muscle tension, neck pain, decreased concentration,
decreased conditioning, agoraphobia

Question 10

What are the three categories of vestibular pathology?

Answer 10

1. Reduced vestibular function (bilateral or unilateral)
2. Mechanical problems (BPPV)
3. Fluctuating (Meniere’s disease)

Question 11

What diseases cause the following duration of dizziness:
sec-min
min-hours
hours-days

Answer 11

Sec to min – BPPV
Min to hours – Meniere’s?
Hours to days – inner ear infection, vestibular neuritis

Question 12

What do you have to rule out prior to investigating vestibular system

Answer 12

Cspine

- do modified VA test

Question 13

Vestibular lesion is ____ the direction of fast phase of nystagmus with acute unilateral vestibular hypofunction

Answer 13

opposite