A positive test is indicated by patient report of a reproduction of vertigo and clinician observation of nystagmus (involuntary eye movement).
Such patients include those who are too anxious about eliciting the uncomfortable symptoms of vertigo, and those who may not have the range of motion necessary to comfortably be in a supine position.
The modification involves the patient moving from a seated position to side-lying without their head extending off the examination table, such as with Dix–Hallpike.
If the test is negative, it makes benign positional vertigo a less likely diagnosis and central nervous system involvement should be considered.
Patients may be too tense, for fear of producing vertigo symptoms, which can prevent the necessary brisk passive movements for the test.
[4] In rare cases a patient may be unable or unwilling to participate in the Dix–Hallpike test due to physical limitations.