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 (defects of the vestibular system)
  • Vestibular neuritis (most common)
  • Benign positional paroxysmal vertigo
• Central causes (defects of the CNS)
  • Posterior circulation stroke

Types

One can distinguish two types of vertigo:

• Systematic (definite directional or rotational component)
• Non-systematic (no motion components)

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.

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.