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

Initial Workup for Dizziness

The initial workup for a patient presenting with dizziness should focus on categorizing the type of dizziness, performing targeted physical examination tests including the HINTS examination, and using appropriate diagnostic studies based on risk stratification. 1

Step 1: Categorize the Type of Dizziness

Dizziness can be classified into four main categories:

1. Vertigo - Sensation of spinning or movement

   • Most common causes: BPPV (42% of cases), vestibular neuritis, Menière's disease 1, 2
   • Key features: Rotational sensation, often triggered by position changes, may have nystagmus

2. Presyncope - Near-fainting sensation

   • Common causes: Orthostatic hypotension, medication effects, cardiac arrhythmias 2
   • Key features: Lightheadedness, feeling of impending loss of consciousness

3. Disequilibrium - Unsteadiness when standing/walking

   • Common causes: Parkinson's disease, diabetic neuropathy, peripheral neuropathy 2
   • Key features: Balance difficulty without sensation of spinning

4. Lightheadedness - Vague sensation of disconnection

   • Common causes: Psychiatric disorders (anxiety, depression), hyperventilation 2
   • Key features: Vague symptoms, often chronic, associated psychological symptoms

Step 2: Perform Targeted Physical Examination

• Vital signs with orthostatic blood pressure measurements

• Cardiovascular examination including heart rate and rhythm

• Neurological examination focusing on:

  • Cranial nerves
  • Cerebellar function (finger-to-nose, heel-to-shin)
  • Gait and balance assessment

• Vestibular examination:

  • HINTS examination (100% sensitivity for detecting stroke vs. 46% for early MRI) 1

    • Head Impulse test: Abnormal in peripheral causes, normal in central causes
    • Nystagmus evaluation: Direction-changing nystagmus suggests central cause
    • Test of Skew: Vertical misalignment suggests central cause

  • Dix-Hallpike maneuver for suspected BPPV 1, 3

    • Positive if vertigo and characteristic nystagmus are provoked

Step 3: Risk Stratification

Assess for red flags that require immediate attention 1:

• Sudden severe headache with dizziness
• New neurological symptoms
• Inability to walk or stand
• Persistent vomiting with dizziness
• Altered mental status

Use the Sudbury Vertigo Risk Score for risk stratification:

• Score >8 indicates 41% risk of serious underlying pathology requiring urgent neuroimaging 1

Step 4: Diagnostic Testing

Based on risk stratification and clinical presentation:

High-Risk Patients:

• MRI brain without contrast (preferred over CT) for:
  • Acute vestibular syndrome with abnormal HINTS examination
  • Presence of neurological deficits
  • High vascular risk patients even with normal examination 1

Lower-Risk Patients:

• Laboratory testing has limited utility but consider:

  • Basic metabolic panel for electrolyte disorders (17.5% of dizziness cases) 4
  • CBC if anemia suspected
  • HbA1c if diabetic neuropathy suspected

• Specialized testing when indicated:

  • ECG for suspected cardiac causes
  • CT temporal bone (without contrast) for suspected peripheral vestibular disorders 1
  • MRA head and neck if vertebrobasilar insufficiency suspected 1

Common Pitfalls to Avoid

1. Overreliance on patient descriptions - Focus on timing and triggers rather than subjective descriptions 3

2. Missing central causes - Remember that CT head is often inadequate for diagnosing acute stroke in vertigo patients 1

3. Unnecessary imaging - Approximately 20% of cases remain undiagnosed despite extensive workup 2

4. Failure to perform the HINTS examination - This simple bedside test is more sensitive than early MRI for stroke detection in acute vestibular syndrome 1

5. Overlooking medication effects - Many medications can cause presyncope, and medication regimens should be thoroughly assessed 2

By following this structured approach, clinicians can efficiently evaluate patients with dizziness and identify those requiring urgent intervention while avoiding unnecessary testing in those with benign causes.