HiNTS Exam
Last updated 01/03/18
Definition
- Neurological eye examination used in the assessment of continuous vertigo to differentiate peripheral from central causes
Features
- Head impulse testing, Nystagmus and Test of Skew (HiNTS)
- More sensitive for detecting stroke than early MRI in acute vestibular syndromes (AVS)
Indications
- Acute Vestibular Syndrome (AVS)
- Reliable only in context of continuous vertigo
- Differentiate vestibular neuritis from vertebrobasilar stroke
Procedure
- Head impulse testing
- Rapid low amplitude rotation of head towards midline
- Patients vision fixed on nearby object, ie: examiners nose
- Nystagmus
- Gaze directed laterally and assessed for oscillation
- Described by direction of rapid correction
- Test of Skew
- Vertical ocular misalignment
- Patient to focus on fixed target
- Cover each eye alternatively
- Observe for corrective movement of uncovered eye on each side
- YouTube: HINTS to diagnose stroke
Interpretation
- Head impulse testing
- Normal: eyes maintain fixation on target
- In context of AVS: central cause likely (strong indicator)
- Abnormal: loss of fixation, eyes move away from target, corrective saccade back to fixation target
- Peripheral cause (weak predictor)
- Nystagmus
- Expected to be dominantly horizontal unidirectional
- Increased intenstity when gaze to direction of fast phase
- Direction of fast beat changes when gaze changes to other direction (direction-changing): central lesion
- Test of Skew
- Central cause
- Normal head impulse test
- Direction changing nystagmus
- Saccade test of skew
- Peripheral cause
- Loss of fixation with corrective movement on head impulse test
- Horizontal unidirectional nystagmus
- Normal test of skew