What is the most likely diagnosis for a patient with positional vertigo characterized by a spinning sensation, dizziness, and transient white visual phenomena when the head position changes?

Benign Paroxysmal Positional Vertigo (BPPV)

The most likely diagnosis is benign paroxysmal positional vertigo (BPPV), specifically posterior canal BPPV, which accounts for 85-95% of BPPV cases and is the most common cause of positional vertigo characterized by brief spinning sensations triggered by head position changes. 1

Clinical Presentation Confirms BPPV

Your description of "room spinning dizzy" with positional triggers is classic for BPPV. The key diagnostic features include:

• Brief duration: Episodes last seconds to less than 1 minute, typically 10-60 seconds from onset to resolution 1, 2
• Positional trigger: Symptoms occur specifically with head position changes relative to gravity—rolling over in bed, looking up, or bending forward 1, 2
• Rotational quality: Patients describe a spinning or rotatory sensation rather than lightheadedness 1
• Latency period: There is a 5-20 second delay (occasionally up to 1 minute) between the position change and symptom onset 1, 2

The "white spots" you mention likely represent visual phenomena associated with the intense vertigo—spatial disorientation and visual disturbances occur in 84% of BPPV patients 3, 2

Confirm Diagnosis with Dix-Hallpike Maneuver

Perform the Dix-Hallpike maneuver bilaterally as the gold-standard diagnostic test. 1, 4 The test is positive when it reproduces:

• Latency: 5-20 seconds before nystagmus and vertigo begin 1
• Characteristic nystagmus: Torsional, upbeating nystagmus toward the affected ear 1, 4
• Self-limiting course: Symptoms increase then resolve within 60 seconds 1, 2

If the Dix-Hallpike is negative but clinical suspicion remains high, perform the supine roll test to evaluate for lateral (horizontal) canal BPPV, which accounts for 5-15% of cases 1

No Imaging or Laboratory Testing Required

Do not order neuroimaging or vestibular testing for typical BPPV with a positive Dix-Hallpike test and no red-flag features. 4 The diagnostic yield of CT is less than 1% and MRI approximately 4% in isolated positional dizziness without concerning features 4

Red Flags That Would Require Urgent MRI

Obtain MRI brain without contrast immediately if any of these are present 4:

• Focal neurological deficits (dysarthria, limb weakness, diplopia, Horner's syndrome)
• Sudden unilateral hearing loss
• Inability to stand or walk
• New severe headache accompanying dizziness
• Downbeating or direction-changing nystagmus
• Normal head-impulse test (suggests central cause)
• Age >50 with vascular risk factors (hypertension, diabetes, atrial fibrillation, prior stroke)

First-Line Treatment: Epley Maneuver

Perform the Epley canalith repositioning maneuver immediately after confirming the diagnosis. 1, 4 This is the definitive treatment:

• Success rate: 80% resolution after 1-3 treatments 1, 4, 5
• With repeat maneuvers: 90-98% success when additional treatments are performed for persistent cases 1, 4
• Same-session treatment: Repeated testing and treatment within the same session is safe and effective with low risk of canal conversion 5

Post-Treatment Expectations

• Some patients experience immediate resolution 4
• Others have transient motion-sickness-type symptoms and mild instability lasting hours to days 4
• Approximately 19% may experience post-treatment downbeating nystagmus and vertigo ("otolithic crisis") after the first or second Epley maneuver—this is self-limiting but requires patient counseling about fall risk 5

Avoid Medications

Do not prescribe vestibular suppressants (meclizine, dimenhydrinate, benzodiazepines) for BPPV. 4 These medications do not correct the underlying mechanical problem and may delay central compensation. If used at all, limit them to brief acute symptom relief during severe distress only 4

Follow-Up and Recurrence Counseling

Reassess within one month after initial treatment to document resolution or persistence 4. Counsel patients about:

• Recurrence risk: BPPV can recur; patients should return promptly for repeat repositioning 4
• Fall risk: Dizziness increases fall risk 12-fold in elderly patients 4
• Activity modifications: Temporary restrictions until symptoms resolve, especially for elderly or frail patients 4

When to Refer for Vestibular Rehabilitation

Refer for vestibular rehabilitation therapy when vertigo persists after 2-3 repositioning attempts. 4 Vestibular rehabilitation significantly improves gait stability compared to medication alone and is particularly beneficial for elderly patients or those with heightened fall risk 4

Common Diagnostic Pitfalls to Avoid

• Do not rely on patient descriptors like "spinning" versus "lightheadedness"—focus instead on timing (seconds), triggers (positional), and associated symptoms 4
• Do not assume atypical presentations exclude BPPV: In up to one-third of cases with atypical histories, Dix-Hallpike testing still reveals positional nystagmus 1
• Do not order comprehensive vestibular testing for straightforward BPPV—it is unnecessary and delays treatment 4
• Do not substitute CT for clinical diagnosis: CT has extremely low yield (<1%) for isolated positional dizziness 4