What is the most appropriate next step in management for a 45-year-old woman with hypertension and type 2 diabetes who presents with acute positional vertigo, nausea, vomiting, a normal neurological exam, a negative head impulse test, and no skew deviation?

Perform the Dix-Hallpike Maneuver to Confirm BPPV Diagnosis

The most appropriate next step is to perform the Dix-Hallpike maneuver to definitively diagnose benign paroxysmal positional vertigo (BPPV), which is the most likely diagnosis based on this patient's presentation. 1

Clinical Reasoning

This 45-year-old woman presents with classic features of posterior canal BPPV:

• Positional trigger: Vertigo provoked by changing position
• Brief duration: Episodes lasting approximately 1 minute
• Acute onset: Symptoms began yesterday
• Associated nausea/vomiting: Common with BPPV
• No neurological red flags: Normal speech, symmetric face, no hearing loss

The examination findings you've described are incomplete and require the Dix-Hallpike maneuver to establish the diagnosis. While you mention "unidirectional horizontal nystagmus," the description of the head impulse test and skew deviation suggests you're evaluating for central causes, but BPPV must be ruled in or out first as it's the most common cause of positional vertigo (42% of vertigo cases in primary care). 1

Why Dix-Hallpike is the Gold Standard

The Dix-Hallpike maneuver is the definitive diagnostic test for posterior canal BPPV and should be performed immediately at bedside. 1 Here's what you're looking for:

Diagnostic criteria for posterior canal BPPV 1:

1. Latency period: 5-20 seconds (rarely up to 1 minute) between completing the maneuver and onset of symptoms
2. Characteristic nystagmus: Torsional (rotatory) and upbeating nystagmus toward the forehead
3. Crescendo-decrescendo pattern: Nystagmus increases then resolves within 60 seconds
4. Subjective vertigo: Patient reports spinning sensation during the test

Important Clinical Pitfalls

The "Negative" Dix-Hallpike Trap

A negative Dix-Hallpike has only a 52% negative predictive value in primary care settings, meaning nearly half of negative tests are false negatives. 1 If your initial test is negative but clinical suspicion remains high (as in this case), repeat the maneuver on a separate visit or consider lateral canal BPPV with the supine roll test. 1

Don't Be Misled by Comorbidities

This patient has diabetes and hypertension—both are risk factors for BPPV and associated with higher recurrence rates, but they don't change your diagnostic approach. 1, 2, 3 The diabetes connection is particularly relevant: BPPV prevalence is higher in type 2 diabetes, though treatment efficacy remains the same. 2, 4

The Head Impulse Test Confusion

You mention a "negative head impulse test" with "catch-up saccades"—this is contradictory. A positive head impulse test (indicating vestibular hypofunction) would show catch-up saccades. However, BPPV typically has a NORMAL head impulse test because the vestibulo-ocular reflex remains intact. 5 The presence of catch-up saccades might suggest vestibular neuritis, but the positional trigger and brief duration strongly favor BPPV over vestibular neuritis (which causes continuous vertigo lasting days). 1

Immediate Management Algorithm

Step 1: Perform Dix-Hallpike maneuver bilaterally

• Test right ear first (head turned 45° right, then supine with neck extended)
• Observe for characteristic nystagmus and ask about vertigo
• If negative, test left ear
• Allow nystagmus to resolve before returning patient upright

Step 2: If Dix-Hallpike is positive → Immediately perform canalith repositioning procedure (Epley maneuver)

• Success rate: ~80% with 1-3 treatments 1
• Can be done at the same visit as diagnosis 1
• Provide antiemetics (ondansetron or meclizine) for nausea only—not for vertigo treatment 1

Step 3: If Dix-Hallpike is negative → Consider lateral canal BPPV

• Perform supine roll test
• If also negative but high clinical suspicion, schedule repeat testing

Step 4: Address orthostatic component

• Her blood pressure shows orthostatic changes (pulse 110→120, BP 155/85→140/80)
• Review her losartan/hydrochlorothiazide dosing
• Ensure adequate hydration (mucous membranes are moist, which is reassuring)

Red Flags That Would Change Management

None are present in this case, but watch for:

• Vertical or direction-changing nystagmus (suggests central cause) 6
• Persistent vertigo >1 minute that doesn't resolve (not BPPV)
• New neurological deficits
• Severe headache (consider posterior circulation stroke)
• Hearing loss (consider Menière's disease or labyrinthitis) 1

Patient Education Points

Once BPPV is confirmed and treated 1:

• Symptoms may take a few days to completely resolve
• Mild residual dizziness is normal for several days
• Recurrence risk is significant (especially with her diabetes and hypertension) 3
• She can be taught self-repositioning maneuvers if symptoms recur
• BPPV does not cause hearing loss or fainting—if these occur, return immediately

The bottom line: Don't order imaging, don't prescribe vestibular suppressants as primary treatment, and don't refer to neurology yet. Perform the Dix-Hallpike maneuver now—it takes 2 minutes and will give you the diagnosis. 1