Vertigo, part 3

Question 1

Acute vestibular syndrome

Answer 1

Persistent continuous ongoing vertigo for hours or days with spontaneous nystamgus and/or gaze evoked nystagmus

Majority of patients with AVS are suffering from vestibular neuritis, but some will have a cerebellar stroke.

Less commonly, multiple sclerosis (MS) can also present with acute vestibular syndrome.

Question 2

Who should undergo HINTS testing?

Answer 2

Only patients with persistent ongoing vertigo AND spontaneous or gaze-evoked nystagmus

Question 3

The affected ear in vestibular neuritis

Answer 3

is the ear opposite to the direction of the nystagmus.

Note that in vestibular neuritis, the fast component of the nystagmus does not change direction when gazing left and right

Question 4

remarks on bidirectional nystagmus

Answer 4

Although this is not always seen in central causes of vertigo, it is a highly specific sign for central vertigo

Question 5

Test of skew is accomplished by

Answer 5

the cover-uncover test
While the patient looks at the examiner’s nose, the examiner cover one eye and the covers the other eye.

Any vertical or diagonally upward or downward movement of the eyes as they are uncovered indicates a central cause of vertigo.

Question 6

Head impulse test is used to demonstrate an

Answer 6

abnoraml vestibulo-ocular reflex on the side of the affected ear, a finding in patients with vestibular neuritis

key components: 20 degrees and random fashion

abnormal if there is a “catch up saccade” in the same direction as the spontaneous nystagmus that is noticeably larger in aamplitude.

Question 7

Remarks on head impulse test

Answer 7

A normal head impulse test is normal in normal persons.

However, a normal head impulse test on a background of persistent vertigo is BAD because it suggests a CENTRAL cause of vertigo.

Question 8

Abnormal PLUS testing suggests

Answer 8

Anterior inferior cerebellar artery stroke
- abnormal head impulse test due to infarction of the labyrinth, as well as part of the cerebellum
- presents with new hearing loss

Question 9

remarks on DHT and HINTS

Answer 9

It should be emphasized that the DHT should be performed only on patients with brief episodes of vertigo who have no spontaneous or gaze-evoked nystagmus.

HINTS plus teting should be performed only on patients with hours or days of continuous constant vertigo and who have nystagmus.

Since the two clinical presentations area easy to distinguish, there is no rationale for performing both the DHT and the HINTS plus exam in the same patient.

Question 10

Patients who have vertigo that lasts between 2 minutes and many hours could have other diagnoses , most commonly:

Answer 10

Vestibular migraine, Meénière’s syndrome, or transient ischemic attack

Question 11

Remarks on posterior circulation TIA

Answer 11

Since HINTS plus testing should be performed only on patients with ongoing vertigo and nystagmus, HINTS plus testing is not appropriate for TIA patients whose vertigo and/or other posterior circulation symptoms have resolved.

Question 12

In cerebellar/brainstem stroke, CT angiography is indicated if

Answer 12

in rare case the stroke score deficit indicates potential benefit for thrombolysis or endovascular clot retrieval

Question 13

In cerebellar/brainstem stroke, emergency MRI is indicated if

Answer 13

acute intervention is not indicated or HINTS plus indicates central cause and more than 48 hours of vertigo

Question 14

In cerebellar/brainstem stroke, delayed MRI is indicated if

Answer 14

acute intervention is not indicated ; HINTS plus indicates central cause and symptoms are less than 48 hours

admit to hospital and perform delayed MRI in 2-3 days

Question 15

When is cerebellar hemorrhage suspected and what is the imaging?

Answer 15

If there is significant ongoing headache or decreased level of consciousness

CT of the head

Question 16

Imaging for Labyrinthitis

Answer 16

Viral: none
Bacterial: MRI

Question 17

These agents may impair vestibular compensation

Answer 17

Benzodiazepines, and thus should not be used for more than 3 days.

Small doses of benzodiazepines may be used sparingly to relieve symptoms of acute vestibular neuritis.

Question 18

Commonly prescribed drugs for vertigo

Answer 18

H1 antihistamines, for their anticholinergic effects

H2 antihistamines are not effective

Question 19

Remarks on betahistine

Answer 19

Betahistine is a strong H3 and weak H1 antagonist that increases cochlear blood flow and decreases peripheral vestibular inputs.

A dosage of 48 mg/day is effective in treating vertigo, and may facilitate vestibular compensation.

Question 20

Diagnostic criteria for vestibular migraine

Answer 20

Moderate or severe episodes of vertigo lasting 5 minutes to 72 hours
Past or current history of migraine
5 or more episodes of vertigo, at least 50% of which have one for the following three migrainous features: visual aura, photophobia or phonophobia, or typical migrain headahces

The patient’s clinical presentation should not be better accounted for by another headache or vestibular problem

No time frame

Question 21

Diagnostic criteria for typical migraine headaches

Answer 21

Shold have at least two of the following four qualities:
- unilateral
- pulsating
- moderate or severe intensity
- aggravated by routine activity

Question 22

Management of Ménière’s syndrome

Answer 22

Antihistamines and betahistine (48 mg PO TID for up to 6 to 12 months)
Combination therapy with triamterene and hydrochlorothiazide is also recommended in confirmed cases.
Calcium channel blocker (Flunarizine 20 mg PO BID)

None of these drug treatments improves hearing.

Question 23

Refer Ménière’s syndrome patients to an otolaryngologist, because

Answer 23

intratympanic injections of corticosteroids or gentamicin are increasingly used to control the frequency of attacks in patients not responding to standard thearpy

Question 24

Treat Ramsay-Hunt syndrome with

Answer 24

antiviral therapy started within 72 hours of the appearnce of vesicles along with symptomatic treatment

Question 25

Drugs that may cause irreversible vestibular toxicity

Answer 25

Loop diuretics (furosemide and ethacrynic acid) Antimalarial quinidine and quinine-derived rugs (chloroquine and mefloquine) Cytotoxic agents (vinbalstine and cisplatin) Aminoglycosides *(usually not reversible; possible improvement with NAC)

Question 26

Can cause irreversible cerebellar toxicity

Answer 26

Phenytoin, toluene, and cancer chemotherapy agents

Question 27

Lateral medullary infarction of the brainstem is also called

Answer 27

Wallenberg's syndrome Classic ipsilateral findings include facial numbness, loss of corneal reflex, Horner's syndrome, and paralysis of the soft palate, pharynx, and larynx (causing dysphagia and dysphonia) Contralateral findings include loss of pain and temperature sensation in the trunk and limbs. Occasionally, lesions of teh sixth, seventh, and eighth cranial nerves can occur, causing vertigo, nausea, vomiting, and nystagmus. These patients require **emergent MRI** and neurologic consultation

Question 28

Remarks on multiple sclerosis

Answer 28

Demyelinating disease can present with vertigo that lasts several hours to several weeks and is usually **not recurrent** The vertigo is mild, with **nystagmus** the most prominent finding on physical examination. Such patients require confirmatory testing with **MRI** as well as vestibular evoked myogenic potentials and referral to a neurologist.