In an adult female with a 1‑day history of acute positional vertigo triggered by leftward head turning, accompanied by vomiting and mild epigastric tenderness, what is the most likely diagnosis and what initial management steps should be taken?

Acute Positional Vertigo with Vomiting: Most Likely Benign Paroxysmal Positional Vertigo (BPPV)

The most likely diagnosis is benign paroxysmal positional vertigo (BPPV) of the left posterior semicircular canal, and you should immediately perform a bilateral Dix-Hallpike maneuver followed by the Epley repositioning maneuver if positive—no imaging or laboratory testing is indicated for this presentation. 1, 2, 3

Clinical Reasoning

Why BPPV is the Leading Diagnosis

• Brief episodic vertigo triggered by specific head position changes (turning left) lasting seconds to minutes is the hallmark of BPPV, which accounts for 42% of all vertigo presentations 1
• Vomiting accompanies BPPV in the majority of cases due to the intense vestibular stimulation, and does not indicate a central cause 4, 5
• The 1-day duration fits the typical acute presentation of BPPV 1
• Up to 50% of BPPV patients do not describe classic "room-spinning" vertigo, instead reporting lightheadedness, dizziness, or feeling "off-balance" 6

The Epigastric Tenderness: A Red Herring

• Mild epigastric tenderness in the context of multiple vomiting episodes is most likely secondary to retching and abdominal muscle strain, not a primary gastrointestinal pathology 1
• The positional trigger and acute vertigo are the dominant clinical features that should guide your diagnosis 1

Immediate Diagnostic Approach

Perform the Dix-Hallpike Maneuver Bilaterally

• The Dix-Hallpike test is the gold standard bedside diagnostic test for posterior canal BPPV 2, 3
• Positive findings include: 5-20 second latency, torsional upbeating nystagmus toward the affected (left) ear, crescendo-decrescendo pattern, and resolution within 60 seconds 1
• Test both sides even though symptoms are triggered by leftward turning, as the pathologic ear may be contralateral to the trigger direction 4

If Dix-Hallpike is Negative

• Perform the supine roll test to assess for lateral (horizontal) canal BPPV, which accounts for 10-15% of BPPV cases 4, 1
• Lateral canal BPPV can present identically to posterior canal BPPV and may be missed if only the Dix-Hallpike is performed 4

Immediate Management

First-Line Treatment: Epley Maneuver

• Perform the Epley canalith repositioning maneuver immediately after a positive Dix-Hallpike test 2, 3
• Success rate is 80% after 1-3 treatments, rising to 90-98% with repeat maneuvers 1, 3
• Many patients experience immediate resolution of vertigo following successful repositioning 1

What NOT to Do

• Do not order brain CT or MRI—imaging has <1% diagnostic yield for typical BPPV and is not recommended by current guidelines 1, 2, 3
• Do not prescribe meclizine or other vestibular suppressants—these medications do not correct the mechanical pathology of BPPV, delay central compensation, and have side effects without therapeutic benefit 1, 3
• Do not order laboratory testing—it has very low yield in patients who have returned to baseline neurologic status 1

Red Flags That Would Change Management

When to Consider Imaging (MRI Brain Without Contrast)

You should obtain urgent MRI if any of the following are present:

• Focal neurological deficits (dysarthria, limb weakness, diplopia, Horner's syndrome) 1
• Severe postural instability with inability to stand or walk 1
• Downbeating or purely vertical nystagmus without torsional component 1
• Direction-changing nystagmus that occurs without head position changes 1
• New severe headache accompanying the vertigo 1
• Sudden unilateral hearing loss 1
• Age >50 years with vascular risk factors (hypertension, diabetes, atrial fibrillation, prior stroke), even with normal neurologic exam, as 11-25% may have posterior circulation stroke 1

HINTS Examination Caveat

• The HINTS examination (Head Impulse, Nystagmus, Test of Skew) should only be used by clinicians specifically trained in its performance—when performed by emergency physicians without specialized training, it is inaccurate and should not replace clinical judgment 2
• Most emergency physicians have not received adequate HINTS training, and it is not standard of care in routine emergency practice as of 2023 2

Expected Post-Treatment Course

• Some patients have transient motion-sickness-type symptoms and mild instability lasting hours to days after successful repositioning 1
• Residual sensitivity to movement can persist for several days to weeks in a subset of patients 1
• Reassess within one month to document resolution or persistence of symptoms 1

When to Refer for Vestibular Rehabilitation

• If vertigo persists after 2-3 repositioning attempts, refer for vestibular rehabilitation therapy 1
• Vestibular rehabilitation significantly improves gait stability compared to medication alone 1

Common Pitfalls to Avoid

• Never assume absence of "room-spinning" excludes BPPV—up to 50% present with atypical descriptions 6
• Do not attribute positional vertigo to gastrointestinal pathology simply because of concurrent vomiting and epigastric tenderness 1
• Failure to perform bilateral Dix-Hallpike testing may miss the affected canal 4
• Assuming a normal neurologic exam excludes stroke is incorrect—75-80% of patients with acute vestibular syndrome from posterior circulation infarct have no focal neurologic deficits 1