What is the initial workup for a patient presenting with dizziness?

Initial Workup for Dizziness

The initial workup for dizziness should focus on categorizing the symptom into one of four types (vertigo, disequilibrium, presyncope, or lightheadedness) through targeted history and specific physical examination tests, with imaging reserved for patients with neurological deficits or high vascular risk factors. 1

Symptom Classification

First, categorize the dizziness into one of four clinical syndromes:

1. Acute Vestibular Syndrome (AVS): Sudden onset of persistent vertigo with nausea/vomiting, gait instability, nystagmus, and head-motion intolerance
2. Triggered Episodic Vestibular Syndrome: Brief episodes triggered by specific movements (e.g., BPPV)
3. Spontaneous Episodic Vestibular Syndrome: Recurrent episodes without clear triggers
4. Chronic Vestibular Syndrome: Persistent dizziness lasting weeks to months

Key History Elements

• Timing: Onset (sudden vs. gradual), duration (seconds, minutes, hours, days)
• Triggers: Head movements, position changes, specific situations
• Associated symptoms: Hearing loss, tinnitus, neurological symptoms, headache
• Risk factors: Age, hypertension, diabetes, atrial fibrillation, previous stroke

Physical Examination

Essential Tests

1. Vital signs: Including orthostatic blood pressure measurements
2. Neurological examination: Cranial nerves, cerebellar function, gait assessment
3. Vestibular examination:
   • Nystagmus assessment: Direction, triggers, fatiguability
   • Dix-Hallpike maneuver: For posterior canal BPPV diagnosis 2
   • Supine Roll Test: For lateral canal BPPV diagnosis 2
   • HINTS examination: For patients with AVS to differentiate peripheral from central causes 2, 1
     • Head Impulse test
     • Nystagmus evaluation
     • Test of Skew

Red Flags Requiring Urgent Evaluation

• Direction-changing nystagmus without head position changes
• Downbeating nystagmus on Dix-Hallpike
• Baseline nystagmus without provocative maneuvers
• Associated neurological symptoms or signs
• Failure to respond to appropriate repositioning maneuvers 1

Diagnostic Testing

Laboratory Tests

• Generally limited role in initial evaluation
• Consider CBC, electrolytes, glucose if relevant to history

Imaging

• Not routinely indicated for all patients with dizziness
• MRI brain without contrast: Preferred when imaging is indicated 2, 1
• CT head without contrast: When MRI unavailable or for urgent evaluation 2

Indications for Imaging

• AVS with abnormal HINTS examination
• AVS with neurological deficits
• High vascular risk patients with AVS even with normal examination
• Chronic undiagnosed dizziness not responding to treatment 2, 1

Specific Clinical Scenarios

1. Suspected BPPV

• Perform Dix-Hallpike maneuver
• If positive: Treat with appropriate canalith repositioning procedure (e.g., Epley maneuver)
• No imaging needed if typical presentation and no neurological deficits 2

2. Acute Vestibular Syndrome

• Perform HINTS examination
• HINTS suggestive of peripheral cause (vestibular neuritis): No immediate imaging needed
• HINTS suggestive of central cause: Urgent MRI (or CT if MRI unavailable) 2
• Prevalence of cerebrovascular disease in AVS is approximately 25%, and may be as high as 75% in high vascular risk cohorts 2

3. Chronic or Recurrent Dizziness

• Consider Menière's disease if associated with hearing loss and tinnitus
• Consider vestibular migraine if history of migraine and episodic symptoms
• Consider psychiatric causes for vague lightheadedness 3

Common Pitfalls to Avoid

1. Relying solely on patient's description: Patients often use terms inconsistently; focus on timing and triggers instead
2. Overuse of imaging: CT has very low yield (<1%) in isolated dizziness without neurological deficits 2
3. Missing stroke in AVS: Up to 11% of patients with acute persistent vertigo but no focal neurological symptoms may have acute infarct 2
4. Inadequate HINTS testing: When performed by specially trained practitioners, HINTS is more sensitive than early MRI for detecting stroke (100% versus 46%) 2

By following this structured approach to dizziness evaluation, clinicians can efficiently diagnose common peripheral vestibular disorders while ensuring that potentially serious central causes are not missed.