From the Guidelines
The HINTS (Head Impulse, Nystagmus, Test of Skew) plus test is a bedside examination used to distinguish between peripheral and central causes of vertigo, particularly in patients with acute vestibular syndrome (AVS) 1.
Key Components of HINTS
- Head Impulse Test: assesses the vestibulo-ocular reflex
- Nystagmus: evaluates the presence and characteristics of abnormal eye movements
- Test of Skew: examines for skew deviation, a sign of central vertigo
Clinical Utility
The HINTS examination is highly sensitive for detecting posterior circulation infarcts, especially when performed by specially trained practitioners 1.
Limitations
However, its accuracy may be dependent on the examiner's experience 1, and some studies suggest that it may not be adequately sensitive to exclude a stroke when used in isolation by non-experts 1.
Clinical Guidelines
Recent clinical guidelines recommend that the HINTS examination be used in conjunction with other clinical assessments and imaging studies, such as MRI, to evaluate patients with AVS 1.
Imaging Recommendations
In patients with AVS and a normal neurologic examination, imaging may not be required if the HINTS examination is negative 1. However, if the HINTS examination is consistent with central vertigo or if there are abnormal neurologic findings, MRI head without IV contrast is recommended as the initial imaging study 1.
From the Research
Definition of HINTS Plus Test
- The HINTS (Head Impulse, Nystagmus, Test of Skew) plus test is a three-part examination used to determine if Acute Vestibular Syndrome (AVS) is due to a peripheral or central cause 2.
- The test includes assessing how the eyes move in response to rapidly turning a person's head (head impulse), assessing the direction of involuntary eye movements (nystagmus), and assessing whether the eyes are aligned or misaligned (test of skew) 2.
- The HINTS Plus examination includes an additional assessment of auditory function 2.
Components of the HINTS Plus Test
- Head impulse test: assesses the vestibulo-ocular reflex function 3.
- Nystagmus test: observes the direction of involuntary eye movements in different gaze positions 3.
- Test of skew: assesses ocular alignment using a prism cross-cover test 3.
- Auditory function test: assesses hearing as part of the HINTS Plus examination 2.
Diagnostic Accuracy of HINTS Plus Test
- The clinical HINTS Plus examination has a sensitivity of 95.3% and specificity of 72.9% for diagnosing a central cause of AVS 2.
- The video-assisted HINTS Plus examination has a sensitivity of 85.0% to 93.8% and specificity of 28.6% to 38.9% for diagnosing a central cause of AVS 2.
- The HINTS test is more sensitive than early MRI diffusion-weighted imaging for diagnosing stroke in AVS 3.