What is the recommended management for a patient with vertigo, negative Head Impulse (HI), left nystagmus, and negative Dix-Hallpike test?

Management of Vertigo with Negative Head Impulse, Left Nystagmus, and Negative Dix-Hallpike

This presentation suggests a central cause of vertigo rather than benign paroxysmal positional vertigo (BPPV), and you should urgently pursue neuroimaging to evaluate for posterior fossa pathology, particularly stroke or other central nervous system lesions.

Understanding the Clinical Presentation

The HINTS examination findings are concerning for a central etiology:

• Negative Head Impulse Test: A normal head impulse test in the setting of acute vertigo is paradoxically worrisome, as peripheral vestibular lesions typically produce an abnormal (positive) head impulse test. A negative test suggests intact vestibulo-ocular reflex, pointing toward central pathology 1.

• Left-beating Nystagmus: The presence of spontaneous nystagmus without the characteristic pattern of BPPV (torsional upbeating nystagmus provoked by positioning) raises concern for central causes 1.

• Negative Dix-Hallpike: This rules out posterior canal BPPV as the primary diagnosis, though it has a negative predictive value of only 52% in primary care settings 1.

Immediate Diagnostic Steps

Perform Supine Roll Test

You must perform a supine roll test to evaluate for lateral (horizontal) semicircular canal BPPV, as this is the second most common form of BPPV (10-15% of cases) and is specifically indicated when the Dix-Hallpike test is negative but symptoms suggest BPPV 1.

• Position the patient supine with head neutral, then quickly rotate the head 90 degrees to each side 1.
• Observe for horizontal nystagmus that may be geotropic (beating toward the ground) or apogeotropic (beating away from the ground) 2.

Consider Central Positional Vertigo (CPPV)

Patients with vertigo symptoms but negative or atypical Dix-Hallpike testing are at increased risk of having central causes identified on imaging 1.

• Central causes that can mimic BPPV include mass lesions, hemorrhage, infarction, and demyelinating disease 1.
• The presence of spontaneous nystagmus without typical positional provocation is a red flag for central pathology 1.

Neuroimaging Recommendations

MRI of the brain is the preferred imaging modality for evaluating suspected central causes of vertigo 1.

• MRI detected acute brain lesions in 11% of patients with episodic vertigo and negative/atypical Dix-Hallpike testing, compared to only 6% with CT 1.
• Imaging is specifically indicated when there are atypical features such as lack of characteristic nystagmus on provoking maneuvers 1.

Symptomatic Management

While pursuing diagnostic workup, symptomatic treatment may be considered:

• Meclizine 25-100 mg daily in divided doses can be used for symptomatic relief of vertigo associated with vestibular system diseases 3.
• Warn patients about drowsiness and avoid concurrent alcohol use 3.
• Use with caution in patients with asthma, glaucoma, or prostatic enlargement due to anticholinergic effects 3.

Common Pitfalls to Avoid

• Do not assume BPPV is ruled out with a single negative Dix-Hallpike: The test may need to be repeated at a separate visit due to its 52% negative predictive value 1.
• Do not miss lateral canal BPPV: Always perform the supine roll test when Dix-Hallpike is negative but clinical suspicion remains 1.
• Do not delay imaging in atypical presentations: The combination of spontaneous nystagmus with negative positional testing warrants urgent evaluation for central causes 1.
• Do not repeat Dix-Hallpike multiple times in the same session: This subjects patients to unnecessary discomfort and may interfere with treatment 1.

Follow-Up Considerations

If supine roll test is also negative and neuroimaging is unrevealing:

• Consider vestibular migraine, which can present with various patterns of vertigo and may have associated migrainous features (headache, photophobia, phonophobia) 1.
• Referral to a specialized dizziness clinic or neurotology may be warranted for patients with persistent symptoms and unclear diagnosis 4.
• Consider repeating positional testing at a follow-up visit, as BPPV can have variable presentations and timing 1.