What could be causing dizziness in an adult with no known serious medical conditions when making quick head movements?

Dizziness with Quick Head Movements

The most likely diagnosis is Benign Paroxysmal Positional Vertigo (BPPV), which is the most common cause of vertigo triggered by head position changes and can be diagnosed and treated at the bedside without imaging. 1

Most Likely Diagnosis: BPPV

BPPV accounts for 42% of peripheral vertigo cases in general practice settings and results from calcium carbonate crystals (otoconia) that dislodge from their normal location in the inner ear and float into the semicircular canals. 2, 3 When you make quick head movements, these crystals shift and create false signals of spinning that typically last less than one minute per episode. 1, 2

The diagnostic gold standard is the Dix-Hallpike maneuver, which should be performed in every patient with brief episodic dizziness triggered by position changes. 2 This bedside test involves:

• Hanging your head off the edge of the examination table while the examiner watches for characteristic eye movements (nystagmus) 1
• Positive findings include rotational and upbeating nystagmus with a brief delay (latency), crescendo-decrescendo pattern, and resolution within 60 seconds 4
• The nystagmus should fatigue with repeated testing 1, 4

When Imaging Is NOT Needed

Imaging is unnecessary if the Dix-Hallpike test shows typical BPPV findings. 1, 4 Normal scans and x-rays cannot confirm BPPV, and ordering imaging for straightforward BPPV only delays effective treatment. 1, 2

Red Flags Requiring Urgent Brain MRI

You need immediate neuroimaging if any of these features are present: 2, 4

• Focal neurological symptoms: weakness, numbness, difficulty speaking (dysarthria), double vision (diplopia), difficulty swallowing
• Severe postural instability with inability to stand or walk
• Atypical nystagmus patterns: purely vertical eye movements without rotation, downbeating nystagmus, or nystagmus that doesn't fatigue with repeated testing
• New severe headache accompanying the dizziness
• Failure to respond to canalith repositioning maneuvers after 1-3 attempts
• Sudden unilateral hearing loss

Critical pitfall: 75-80% of posterior circulation strokes present without focal neurological deficits, so a normal neurologic exam does not exclude stroke. 2, 5 CT head has only 20-40% sensitivity for posterior circulation strokes and should not be used when stroke is suspected—MRI is required. 2

Treatment for BPPV

The Epley maneuver (canalith repositioning procedure) is the treatment of choice, with 80% success after 1-3 treatments and 90-98% success with repeat maneuvers. 2, 6 This bedside procedure takes only a few minutes and guides the crystals back to their proper location. 1 The maneuver can be performed at the same visit as the diagnostic Dix-Hallpike test. 1

Medications like meclizine may provide temporary symptom relief for nausea but do not treat the underlying cause. 7 Vestibular rehabilitation therapy can be added if symptoms persist. 8

Alternative Diagnoses to Consider

If the Dix-Hallpike test is negative or atypical, consider: 2, 4

Vestibular migraine (extremely common but under-recognized):

• Episodes can be brief (<15 minutes) or prolonged (>24 hours) 4
• Look for current or past migraine history, family history of migraine, photophobia, phonophobia, or visual aura during at least 50% of vertigo episodes 2, 4
• Hearing remains stable or absent—not fluctuating 4

Ménière's disease:

• Classic triad: episodic vertigo lasting hours, fluctuating sensorineural hearing loss that worsens over time, tinnitus, and aural fullness 2, 4
• The key distinguishing feature from vestibular migraine is progressive fluctuating hearing loss 4

Vestibular neuritis:

• Acute onset of severe continuous vertigo lasting days to weeks with nausea and vomiting 2
• No hearing loss (unlike labyrinthitis) 6

Central causes (stroke, tumor, demyelination):

• Require urgent MRI if red flags present 1, 2
• Approximately 25% of patients with acute vestibular syndrome have cerebrovascular disease 5

Common Pitfalls to Avoid

• Skipping the Dix-Hallpike maneuver: This is the gold standard diagnostic test and should never be omitted 2
• Relying on patient descriptions of "spinning" versus "lightheadedness" instead of focusing on timing and specific triggers 2
• Assuming normal neurologic exam excludes stroke: Most posterior circulation strokes lack focal deficits 2, 5
• Overlooking vestibular migraine: This is extremely common in young patients but frequently missed 2, 4
• Ordering imaging for typical BPPV: This wastes time and resources when bedside treatment is immediately available 2