Vertigo

Vertigo is the sensation that you are moving, or everything moves around you. It's a common symptom in a variety of disorders, ranging from harmless to life-threatening.

Acute vestibular syndrome is defined as the presence of severe vertigo lasting more than 24 hours which causes nausea and vomiting and an intolerance to head movement (because it makes the vertigo worse).

Etiology

The most common causes include:

• Non-ENT causes
  • Orthostatic hypotension
  • Hypertension
  • Heart disease
  • Anaemia
• Peripheral causes
  • Vestibular neuritis (most common)
  • Benign positional paroxysmal vertigo
• Central causes
  • Posterior circulation stroke or TIA
  • Vestibular migraine

Types

One can distinguish two types of vertigo:

• Peripheral vertigo
• Central vertigo

Peripheral vertigo is the most common and is caused by dysfunction of the vestibular system. Central vertigo is rare but can be fatal, and is due to disorder of the CNS. In Hungarian literature, these are called harmonic and disharmonic vestibular syndromes, respectively.

Clinical features

Nystagmus, nausea, and vomiting are all common features in people with vertigo. In case of focal neurological signs, posterior circulation stroke is likely. In case of tinnitus or hearing loss, peripheral causes are more likely.

	Peripheral vertigo (harmonic vestibular syndrome)	Central vertigo (disharmonic vestibular syndrome)
Nystagmus direction	Never changes direction Fast component away from affected ear. (Slow component toward affected ear)	Direction may change based on gaze Fast component toward affected side. (Slow component away from affected ear)
Nystagmus type	Horizontal or combined horizontal and rotational Never purely rotational or purely vertical	Any direction Purely vertical or purely rotational is always central
Sense of motion	Severe, nausea and vomiting common	Usually mild
Romberg test	Patient falls toward the affected ear	Patient falls toward the affected side
Does visual fixation suppress nystagmus?	Yes	No
Postural instability	Instability toward affected side Walking usually preserved	Severe instability Walking usually difficult
Other inner ear symptoms (hearing loss, tinnitus)	May be present	Usually not present
Ataxia, diplopia, dysphagia, weakness, other neurological symptoms	Absent	Often present

Diagnosis and evaluation

HINTS

The HINTS exam is essential for screening for posterior circulation stroke in patients presenting with acute-onset sustained vertigo (not episodic or paroxysmal vertigo). The name is a mnemonic for three tests. The patient must have vertigo during the examination for it to be valid.

Head Impulse test

The head impulse test is performed by asking the patient to fixate on your nose. The examiner gently turns the patient's head 30 degrees to the side, and then rapidly turns the head back so the patient faces forward again. This is repeated to both side.

If there is no dysfunction of the peripheral vestibular system (negative test), the vestibulo-ocular reflex ensures that the examinee will be able to fixate their eyes on the examiner's nose despite the head movements.

If there is dysfunction of the peripheral vestibular system (positive test), the vestibulo-ocular reflex is lost. This causes the examinee to lose fixation on the examiner's nose for a second after the rapid head turn (the eyes move with the head), before the eyes rapidly move to fixate on the nose again.

Nystagmus

Ask the patient to look to the left. Look for nystagmus. Then do the same for the other side.

If there is no dysfunction of the peripheral vestibular system (negative test), the nystagmus will change direction when the patient changes their gaze. In other words, if the nystagmus beats to the left when looking left, it will change to beating right when the patient looks right.

If there is dysfunction of the peripheral vestibular system (positive test), the nystagmus will maintain the same direction irrespective of the direction of gaze.

Test of skew

Ask the examinee to focus their gaze on the examiner's nose. The examiner must cover one of the examinee's eyes, then quickly move the cover to the other eye. Observe for uncovered eye for vertical movement. Repeat for the other side.

If there is no dysfunction of the peripheral vestibular system (negative test), the eye from which the cover was moved will exhibit a vertical movement.

If there is dysfunction of the peripheral vestibular system (positive test), there will be no such vertical movement.

Interpretation of HINTS

If the head impulse test, nystagmus test, and test of skew are ALL positive, and there are no focal neurological signs, then a peripheral cause of vertigo is more likely.

If ANY of the tests are negative, or if there are any focal neurologal signs, then posterior circulation stroke is more likely, and the patient requires neuroimaging for stroke.

Differential diagnosis

Peripheral vertigo

Disorder	Duration of episode	Recurrence of vertigo	Other symptoms	Other clinical features
Vestibular neuritis	Days	Single episode	Symptoms of viral infection earlier or during. Intolerance to head movement, spontaneous nystagmus, and a tendence to fall to the diseased side	None
Benign paroxysmal positional vertigo	Seconds	Recurrent episodes	Specific head movements and positions precipitate symptoms	Positive Dix-Hallpike test
Ménière disease	Hours	Recurrent episodes	Hearing loss, tinnitus	Audiometry shows SN hearing loss
Otitis media	Days	Single episode	Ear pain	Characteristic findings on otoscopy

Central vertigo

Disorder	Duration of episode	Recurrence of vertigo	Other symptoms	Other clinical features
Vestibular migraine	Minutes	Recurrent episodes	Headache, other symptoms of migraine	None
TIA of vertebrobasilar system	Minutes	Single or multiple episodes	Other brainstem or cerebellar symptoms	MRI confirms ischaemia
Brainstem stroke	Days	Single episode	Other brainstem symptoms	MRI confirms infarct
Cerebellar stroke	Days	Single episode	Other cerebellar symptoms	MRI confirms infarct