What is the initial step in diagnosing and managing dizziness?

Initial Diagnostic Approach to Dizziness

The initial step in diagnosing and managing dizziness should be a structured evaluation focused on timing and triggers of symptoms, followed by orthostatic blood pressure measurement and specific diagnostic maneuvers like the Dix-Hallpike test. 1, 2

Classification of Dizziness

Dizziness should be classified into one of four categories based on the patient's description:

1. Vertigo: Sensation of rotation or spinning

   • Brief (seconds to minutes) for BPPV; hours to days for other causes
   • Often triggered by positional changes
   • May have associated nystagmus
   • May include hearing loss or tinnitus with certain conditions

2. Presyncope: Feeling of impending faint

   • Often related to orthostatic hypotension
   • May have associated palpitations

3. Disequilibrium: Unsteadiness or imbalance

   • Often constant
   • Worse when walking

4. Lightheadedness: Vague sensation of disconnection

   • May be associated with psychiatric conditions
   • Often chronic or recurrent

Key Diagnostic Steps

1. Orthostatic Blood Pressure Measurement

• Measure BP and heart rate while supine and after standing for 3 minutes
• Diagnostic for orthostatic hypotension if systolic BP drops ≥20 mmHg or diastolic BP drops ≥10 mmHg 3, 1
• Orthostatic hypotension is a common cause of dizziness, especially in elderly patients and those on vasoactive medications 3

2. Vestibular Assessment

• Dix-Hallpike Maneuver: Essential for diagnosing BPPV

  • Positive test shows characteristic nystagmus
  • BPPV is the most common cause of vertigo 4, 2

• HINTS Examination: For acute vestibular syndrome

  • Head-impulse test
  • Nystagmus evaluation
  • Test of skew
  • Abnormal HINTS exam suggests central cause requiring urgent evaluation 1

3. Neurological Examination

• Assess for focal neurological deficits
• Evaluate gait and balance
• Check for signs of Parkinson's disease or peripheral neuropathy if disequilibrium is present 4

Special Considerations

When to Consider Imaging

Neuroimaging (preferably MRI) is indicated when:

• Acute vestibular syndrome with abnormal HINTS examination
• Neurological deficits are present
• High vascular risk patients with acute vestibular syndrome
• Chronic undiagnosed dizziness not responding to treatment 1

Common Pitfalls to Avoid

• Focusing on quality of dizziness rather than timing and triggers
• Failing to perform the Dix-Hallpike maneuver in patients with positional vertigo
• Routinely prescribing vestibular suppressants for BPPV
• Missing central causes of vertigo by not performing the HINTS examination
• Ordering unnecessary imaging studies in patients with clear peripheral vertigo 1

Initial Management Based on Diagnosis

• BPPV: Canalith repositioning procedures (Epley maneuver) - 80% success rate 1
• Orthostatic Hypotension: Medication adjustment, hydration, compression stockings, gradual position changes 3, 1
• Vestibular Neuritis: Early corticosteroid therapy 1
• Ménière's Disease: Consider intratympanic dexamethasone or gentamicin 4
• Vertigo (symptomatic relief): Meclizine for vestibular system disorders 5

Assessment Tools

Consider validated assessment tools for ongoing evaluation:

• Activities-Specific Balance Confidence Scale
• Dizziness Handicap Inventory
• Dynamic Gait Index
• Timed Up & Go test 1

Remember that approximately 20% of dizziness cases may remain without a definitive diagnosis despite thorough evaluation 4. In these cases, symptomatic management and close follow-up are appropriate while avoiding unnecessary testing.