Neurology-Dizziness And Vertigo

Front 1

Name the three sensory systems subserving spatial orientation and posture.

Back 1

1) vestibular system
2) somatosensory system
3) visual system

Front 2

What causes Vertigo?

Back 2

Vertigo is usually due to a disturbance in the vestibular system

Front 3

The inner ear consist of which structure and name its function.

Back 3

1) Three semicircular canals
2) otolithic apparatus (utricle and saccule)

canals transduce angular acceleration

Otolith transduce linear acceleration and the static gravitational forces that provide a sense of head position in space

Front 4

What is the most common cause for pathologic vertigo?

Back 4

Vestibular dysfunction.

The vertigo is associated with jerk nystagmus and is frequently accompanied by nausea, postural unsteadiness, and gait ataxia.

Since vertigo increases with rapid head movements, patients tend to hold their heads still.

Front 5

What are the features of a rotational vertigo in labyrinthine dysfunction?

Back 5

Hallucination of movement-away from side the lesion.

Nystagmus-away from side of lesion

Tendency to fall toward the side of the lesion

Front 6

What are the causes of acute unilateral labyrinthine dysfunction?

Back 6

infection,
trauma,
ischemia.

Front 7

Name the other terms used to describe unilateral labyrinthine dysfunction.

Back 7

acute labyrinthitis
acute peripheral vestibulopathy
vestibular neuritis

Front 8

What are the features of labyrinthine ischaemia?

Back 8

Presents with the abrupt onset of severe vertigo, nausea, and vomiting, but without tinnitus or hearing loss.

It is due to occlusion of the labyrinthine branch of the internal auditory artery, and may be the sole manifestation of vertebrobasilar insufficiency

Front 9

what causes acute bilateral labyrinthine dysfunction?

Back 9

Toxins such as drugs or alcohol.

Most common- Aminoglycoside

Damage the hair cells of the vestibular end organs and may cause a permanent disorder of equilibrium.

Front 10

what causes recurrent unilateral labyrinthine dysfunction?

Back 10

1) Meniere's disease-with hearing loss and tinnitus.
2) Vestibular neuronitis-without auditory manifestation.
3) Vertebrobasillar insufficiency- without concomitant motor, sensory, visual, cranial nerve, or cerebellar signs

Front 11

What is the pattern of nystagmus in BPPV?

Back 11

When supine, with the head turned to the side of the offending ear (bad ear down), the lower eye displays a large-amplitude torsional nystagmus, and the upper eye has a lesser degree of torsion combined with upbeating nystagmus.

If the eyes are directed to the upper ear, the vertical nystagmus in the upper eye increases in amplitude.

Mild dysequilibrium when upright may also be present

Front 12

How do you differentiate between a vertigo/nystagmus caused by BPPV vs central positional vertigo?

Back 12

The vertigo/nystagmus in BPPV is severely intense but is usually fatiguable and habitual.

Meaning that the vertigo/nystagmus disappears with maintenance of the offending position.

And lessens with repeated trials.

Front 13

What is the most common cause of 8th cranial nerve dysfunction?

Back 13

schwannoma (acoustic neuroma) or a meningioma.

These tumors grow slowly and produce such a gradual reduction of labyrinthine output that central compensatory mechanisms can prevent or minimize the vertigo; auditory symptoms are the most common manifestations

Front 14

How do you differentiate between peripheral vs central vertigo?

Back 14

In peripheral vertigo:
1) visual fixation inhibits nystagmus and vertigo.

2) Vertical or purely torsional nystagmus does NOT occur.

3) Often present with tinnitus or deafness

4) No associated CNS abnormalities.

5) vertigo usually markedly severe.

Front 15

Common causes of peripheral vertigo?

Back 15

BPPV
infection (labyrinthitis), Ménière's,
neuronitis,
ischemia,
trauma,
toxin

Front 16

Common causes of central vertigo?

Back 16

Vascular,
demyelinating,
neoplasm

Front 17

What features help to differentiate between a central vs peripheral vertigo?

Back 17

In central vertigo:
1) There is no inhibition with visual fixation

2) tinnitus or deafness usually absent

3) Extremely common to have associated CNS abnormalities
(e.g., diplopia, hiccups, cranial neuropathies, dysarthria)

4) severity usually mild

Front 18

How to diagnose psychogenic vertigo?

Back 18

Organic vertigo is accompanied by nystagmus

A psychogenic etiology is almost certain when nystagmus is absent during a vertiginous episode.

The symptoms often develop after an episode of acute labyrinthine dysfunction.

Front 19

What are the treatment options for vertigo?

Back 19

1) bed rest (1–2 days maximum)

2) vestibular suppressant drugs such as antihistaminics (meclizine, dimenhydrinate, promethazine),

3) tranquilizers with GABA-ergic effects (diazepam, clonazepam),

4) phenothiazines (prochlorperazine)

5) glucocorticoids