What is the appropriate workup for a patient complaining of dizziness?

Workup for Patient Complaint of Dizziness

The appropriate workup for dizziness should focus on timing and triggers rather than symptom quality, with targeted physical examination including HINTS testing, orthostatic measurements, and neurological assessment to differentiate between peripheral and central causes. 1

Initial Assessment Framework

History - Focus on Timing and Triggers

• Timing patterns:

  • Acute Vestibular Syndrome (AVS): Continuous dizziness lasting days to weeks
  • Triggered Episodic Vestibular Syndrome: Dizziness triggered by specific actions
  • Spontaneous Episodic Vestibular Syndrome: Untriggered episodes lasting minutes to hours
  • Chronic Vestibular Syndrome: Dizziness lasting weeks to months 1, 2

• Key triggers to identify:

  • Head position changes (suggests BPPV)
  • Loud sounds or pressure changes (suggests Meniere's disease)
  • Associated symptoms (hearing loss, tinnitus, headache)
  • Medication use or recent changes 1, 3

Physical Examination

1. Vital signs with orthostatic measurements:

   • Measure BP/HR supine, then after standing 1-3 minutes
   • Orthostatic hypotension: Drop in systolic BP ≥20 mmHg or diastolic BP ≥10 mmHg 1

2. HINTS examination (crucial for differentiating peripheral from central causes):

   • Head-Impulse test: Abnormal in peripheral causes, normal in central causes
   • Nystagmus: Direction-changing in central causes, unidirectional in peripheral causes
   • Test of Skew: Vertical misalignment suggests central pathology 1, 2

3. Dix-Hallpike maneuver for suspected BPPV:

   • Positive if provokes vertigo and characteristic nystagmus 1, 2

4. Comprehensive neurological examination:

   • Cranial nerves
   • Motor strength and coordination
   • Gait assessment 1

5. Cardiovascular examination:

   • Heart rate and rhythm
   • Murmurs or abnormal heart sounds 1

Diagnostic Testing Algorithm

Laboratory Testing

• Generally limited role in diagnosis 4, 5
• Consider based on history:
  • CBC if anemia suspected
  • Electrolytes if dehydration or medication effect suspected
  • Glucose if diabetic

Imaging

• MRI brain indicated for:

  • AVS with abnormal HINTS examination
  • AVS with neurological deficits
  • High vascular risk patients with AVS even with normal examination 1

• CT head without contrast:

  • Only when MRI unavailable (note: low sensitivity 20-40% for posterior fossa lesions) 1

• No imaging needed for:

  • HINTS-negative acute vestibular syndrome (risk of brain lesion is 0%)
  • Typical BPPV with positive Dix-Hallpike and response to repositioning 1

Differential Diagnosis Framework

Peripheral Vestibular Causes

1. Benign Paroxysmal Positional Vertigo (BPPV):

   • Brief vertigo triggered by head position changes
   • Positive Dix-Hallpike maneuver 1, 4

2. Vestibular Neuritis/Labyrinthitis:

   • Acute onset, persistent vertigo for days
   • No hearing loss (neuritis) or with hearing loss (labyrinthitis) 1, 2

3. Meniere's Disease:

   • Episodes with hearing loss, tinnitus, aural fullness
   • Characteristic audiometric findings 1, 4

Central Vestibular Causes

1. Stroke/TIA:

   • Sudden onset, often with other neurological deficits
   • Abnormal HINTS exam, risk factors for vascular disease 1

2. Vestibular Migraine:

   • Variable duration, history of migraine
   • Photophobia, mild or absent hearing loss 1, 2

Non-vestibular Causes

1. Presyncope:

   • Orthostatic hypotension
   • Cardiac arrhythmias
   • Medication effects 1, 4

2. Disequilibrium:

   • Parkinson's disease
   • Diabetic neuropathy
   • Other neurological disorders 4

3. Psychiatric causes:

   • Anxiety disorders
   • Depression
   • Hyperventilation syndrome 4

Common Pitfalls and Caveats

• Overreliance on symptom quality: Patients have difficulty describing dizziness quality; focus on timing and triggers instead 2, 3

• Missing central causes: Always perform HINTS exam in acute vertigo to avoid missing stroke 1, 2

• Unnecessary imaging: Approximately 20% of cases remain undiagnosed despite extensive testing; imaging is often not helpful in uncomplicated cases 4, 5

• Medication causes: Many medications can cause dizziness; always review the patient's medication list 4

• Excessive vestibular suppressants: These can delay central compensation and recovery; use only short-term for acute symptoms 1, 3

• Failure to recognize BPPV: This common and treatable cause is often missed; always perform Dix-Hallpike when history suggests positional triggers 2, 6