What is the clinical approach to managing new-onset dizziness?

Clinical Approach to New-Onset Dizziness

Use the timing-and-triggers approach rather than symptom quality (vertigo vs. lightheadedness) to categorize dizziness, as symptom quality is unreliable for diagnosis and does not distinguish benign from dangerous causes 1, 2, 3.

Algorithmic Classification by Timing and Triggers

Divide patients into three diagnostic categories based on when and how dizziness occurs:

1. Acute Vestibular Syndrome (AVS)

Presentation: Sudden-onset, continuous vertigo/dizziness lasting >24 hours with nausea/vomiting, gait instability, head-motion intolerance, and nystagmus 4.

Critical distinction: The most dangerous diagnosis to exclude is posterior circulation stroke (cerebellum/brainstem), which occurs in approximately 25% of AVS cases and up to 75% in high vascular risk patients 5. Importantly, 75-80% of stroke patients presenting with AVS have NO focal neurologic deficits 5.

Diagnostic approach:

• Perform HINTS examination (Head Impulse, Nystagmus, Test of Skew) when specially trained—this is more sensitive than early MRI for stroke detection 5, 4
• Normal HINTS suggests peripheral cause (vestibular neuritis/labyrinthitis)
• Abnormal HINTS suggests central cause requiring urgent imaging

Imaging decisions:

• CT has very low yield (<1%) in patients with normal neurologic exam 5
• MRI brain without and with contrast is the appropriate imaging modality when central cause suspected, as it detects acute infarcts in 11% of AVS patients without focal deficits 5
• Do not rely on normal neurologic exam alone to exclude stroke

Common pitfall: Assuming normal neurologic examination excludes stroke—it does not. One-third to two-thirds of posterior circulation strokes lack focal neurologic signs 5.

2. Triggered Episodic Vestibular Syndrome

Presentation: Brief episodes (<1 minute) triggered by specific head position changes.

Diagnostic approach:

• Perform Dix-Hallpike maneuver for posterior canal BPPV
• Perform supine roll test for horizontal canal BPPV 3
• Typical nystagmus pattern confirms benign paroxysmal positional vertigo (BPPV)

Management:

• Treat BPPV with repositioning maneuvers at bedside (Epley maneuver for posterior canal, barbecue roll for horizontal canal) 2
• Imaging is unnecessary for typical BPPV with characteristic nystagmus on Dix-Hallpike 5
• Consider MRI only for atypical presentations or central positional vertigo (6-11% have acute brain lesions) 5

3. Spontaneous Episodic Vestibular Syndrome

Presentation: Recurrent episodes lasting minutes to hours without positional trigger.

Differential diagnosis:

• Vestibular migraine (most common)
• Transient ischemic attack
• Meniere's disease

Diagnostic approach:

• Assess for migraine features and vascular risk factors
• Include hearing assessment as integral part of evaluation 6
• Consider vascular workup if high stroke risk

Beyond Stroke and Peripheral Vestibular Disorders

Screen for non-vestibular causes 7:

• Drug side-effects/intoxication
• Electrolyte disturbances
• Cardiac disease (arrhythmia, orthostatic hypotension)
• Severe anemia
• Endocrine disorders
• Carbon monoxide poisoning
• Demyelinating disease
• Posterior fossa mass lesions
• Acute thiamine deficiency

Note: Acute physiological abnormalities (hypotension, fever, severe anemia) may unmask previously compensated vestibular impairments 7.

Treatment Principles

Acute phase:

• Avoid benzodiazepines for symptomatic treatment—no evidence of superiority over placebo 1
• Do not use corticosteroids for vestibular neuritis—no proven benefit over placebo 1
• Vestibular suppressants (if used) only for first 24-48 hours maximum

Subacute and chronic management:

• Vestibular rehabilitation therapy is the cornerstone of treatment for nearly all vestibular disorders 6, 4
• For persistent postural-perceptual dizziness (PPPD): combine vestibular rehabilitation, cognitive behavioral therapy, and SSRIs (sertraline) 8
• PPPD often follows acute vestibular events and requires multimodal approach

Red Flags Requiring Urgent Evaluation

• New severe headache
• Diplopia or visual loss
• Dysarthria or dysphagia
• Limb weakness or numbness
• Altered consciousness
• High vascular risk factors with AVS presentation
• Inability to stand/walk independently

The timing-and-triggers approach reduces misdiagnosis, decreases unnecessary testing and hospitalization, and prevents incorrect treatments compared to the outdated symptom-quality approach 3.