Template:HINTS Exam Procedure

Inclusion Criteria

• HINTS exam should only be used in patient with acute persistent vertigo, nystagmus, and a normal neurological exam.
• HINTS exam, when done correctly, has high sensitivity and specificity in distinguishing peripheral vs central etiologies of vertigo
• Note that the original study was done by neuro-ophthalmologists in a differentiated patient base. This exam has not been studied in a large ED population yet

The 3 components of the HINTS exam include:

HINTS Test	Reassuring Finding
Head Impulse Test	Abnormal (corrective saccade)
Nystagmus	Unidirectional, horizontal
Test of Skew	No skew deviation

• Always use correct terminology; "HINTS negative" does not convey a clear interpretation. State "HINTS central" or "HINTS peripheral" as suggested in literature
  • If able, specify the exact exam finding as shown by chart above

Head Impulse Test

Test of vestibulo-ocular reflex function

1. Have patient fix their eyes on your nose
2. Move their head rapidly in the horizontal plane to the left and right
   • When the head is turned towards the normal side, the vestibular ocular reflex remains intact and eyes continue to fixate on the visual target
   • When the head is turned towards the affected side, the vestibular ocular reflex fails and the eyes make a visible corrective saccade to re-fixate on the visual target
   • Normally, a functional vestibular system will identify any movement of the head position and instantaneously correct eye movement accordingly so that the center of the vision remains on a target.
     • This reflex fails in peripheral causes of vertigo affecting the vestibulocochlear nerve unilaterally; thus, failure of the reflex unilaterally is reassuring (since the cause is peripheral)
   • Note that in central causes of vertigo, test may show normal reflex response OR failure of the reflex BILATERALLY

Nystagmus

1. Observation for nystagmus in primary, right, and left gaze
   • No nystagmus (normal) or only horizontal unilateral nystagmus (fast direction only in one direction) is reassuring
   • Any other type of nystagmus is abnormal, including vertical or bidirectional nystagmus

Test of Skew

1. Have patient look at your nose with their eyes and then cover one eye
2. Then rapidly uncover the eye and quickly look to see if the eye moves to re-align.
3. Repeat with on each eye
   • Skew deviation is a fairly specific predictor of brainstem involvement in patients with acute vestibular syndrome. The presence of skew may help identify stroke when a positive head impulse test falsely suggests a peripheral lesion.
   • Skew is also known vertical dysconjugate gaze and is a sign of a central lesion