ENT Special Examinations

HINTS Exam

• A clinical test battery to distinguish central from peripheral causes of acute vestibular syndrome, generally used when patients have persistent vertigo and nystagmus for ≥24 hours

• Head Impulse Test

  • Patient focuses on a target, examiner rapidly turns the head to one side while observing the eyes

  • A peripheral lesion (e.g. vestibular neuritis) typically shows a positive (abnormal) head impulse: corrective saccade back to the target

  • A normal head impulse (no saccade) in a patient with acute continuous vertigo raises concern for a central lesion (e.g. cerebellar stroke)

  • If the head impulse test is positive in both directions or inconsistent, consider central pathology

• Nystagmus

  • Peripheral (vestibular) causes typically produce unidirectional, horizontal nystagmus that may be inhibited by fixation

  • Central causes can have purely vertical, purely torsional, or direction-changing nystagmus; nystagmus that changes direction when looking in different gaze positions is particularly concerning

• Test of Skew

  • Performed via the cover-uncover test to check for vertical skew deviation

  • A negative test (no vertical misalignment) usually suggests a peripheral cause

  • A positive test (vertical realignment when one eye is uncovered) is more indicative of a central lesion

• Interpretation

  • High suspicion of central cause (possible stroke) if:

    • Normal (negative) head impulse

    • Direction-changing or purely vertical nystagmus

    • Positive test of skew

  • Peripheral cause more likely if:

    • Positive (abnormal) head impulse in one direction, unidirectional horizontal nystagmus, and no skew deviation

  • HINTS is most accurate when all three components are considered together

Rinne’s Test

• Compares air conduction (AC) to bone conduction (BC) in each ear

• Positive (normal) Rinne: AC > BC

  • Indicates either normal hearing or sensorineural hearing loss (SNHL) in that ear

• Negative Rinne: BC > AC

  • Indicates conductive hearing loss (CHL) in that ear

Weber’s Test

• Tuning fork placed on the centre of the forehead or top of the head

• Patient reports which ear (if any) the sound lateralises to

• In CHL, sound lateralises to the affected (poorer hearing) ear

• In SNHL, sound lateralises to the unaffected (better hearing) ear

Notes:

• The HINTS exam is primarily used in continuous, severe vertigo to help exclude a posterior circulation stroke

• Any suspicion of central lesion (e.g. inconsistent or concerning HINTS findings, new neurological deficits, severe headache) warrants urgent neuroimaging

• Rinne’s and Weber’s tests are commonly performed together to localise hearing loss as conductive or sensorineural

• Patients with significant hearing changes, persistent vertigo, or abnormal HINTS findings often benefit from ENT or neurology referral

• Thorough history and examination are crucial, including evaluation of risk factors for stroke in acute vertigo (older age, hypertension, diabetes, atrial fibrillation) and potential causes of ear disease (otitis media, tympanic membrane perforation)