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

Initial Workup for Dizziness

The initial workup for dizziness should focus on timing, triggers, and associated symptoms rather than the quality of dizziness, with targeted physical examination including the Dix-Hallpike maneuver for positional vertigo, HINTS examination for acute vestibular syndrome, and orthostatic blood pressure measurement. 1

Classification and Approach

Dizziness can be classified into four main categories:

1. Vertigo: Sensation of spinning or rotation
2. Presyncope: Near-fainting sensation
3. Disequilibrium: Imbalance or unsteadiness
4. Lightheadedness: Vague sensation of disconnection

However, the most effective approach is to focus on:

• Timing: Episodic vs. continuous
• Triggers: Positional changes, specific activities
• Associated symptoms: Hearing loss, neurological deficits

Key Elements of History

• Onset and duration: Sudden vs. gradual, seconds vs. days
• Aggravating/alleviating factors: Position changes, movement
• Associated symptoms:
  • Hearing loss, tinnitus, aural fullness (suggests peripheral cause)
  • Headache, visual changes, neurological deficits (suggests central cause)
  • Palpitations, shortness of breath (suggests cardiovascular cause)

Essential Physical Examination

1. Vital signs: Including orthostatic blood pressure (drop of ≥20 mmHg systolic or ≥10 mmHg diastolic within 3 minutes of standing indicates orthostatic hypotension) 1

2. Neurological examination:

   • Cranial nerves
   • Motor and sensory function
   • Coordination tests
   • Gait assessment

3. Vestibular assessment:

   • Nystagmus evaluation: Direction, trigger factors
   • Dix-Hallpike maneuver: For suspected BPPV (positive test shows nystagmus and reproduces vertigo) 1
   • HINTS examination (for acute vestibular syndrome):
     • Head Impulse test
     • Nystagmus evaluation
     • Test of Skew
     • Normal HINTS with unidirectional horizontal nystagmus suggests peripheral cause 1

4. Cardiovascular examination:

   • Heart rate and rhythm
   • Carotid auscultation

Diagnostic Testing

The American College of Radiology recommends against routine CT scans for isolated vertigo without focal neurological deficits 1. Imaging should be reserved for:

• Vertigo with severe headache
• Age >60 years with acute symptoms
• Focal neurological deficits
• Trauma above the clavicle
• Abnormal HINTS examination

MRI brain (without contrast) is indicated for:

• Acute vestibular syndrome with abnormal HINTS exam
• Neurological deficits
• High vascular risk patients even with normal examination
• Chronic undiagnosed dizziness not responding to treatment 1

Laboratory testing plays a limited role but may include:

• Complete blood count (if anemia suspected)
• Electrolytes (if dehydration or medication effect suspected)
• Glucose (if diabetic)

Common Diagnoses and Specific Findings

1. Benign Paroxysmal Positional Vertigo (BPPV):

   • Brief vertigo with position changes
   • Positive Dix-Hallpike test
   • Treatment: Canalith Repositioning Procedure (Epley maneuver) 1

2. Vestibular Neuritis/Labyrinthitis:

   • Sudden severe vertigo with prolonged nausea
   • Labyrinthitis includes hearing loss
   • Treatment: Early corticosteroid therapy 1

3. Menière's Disease:

   • Episodic vertigo with hearing loss, tinnitus, aural fullness
   • The American Academy of Otolaryngology-Head and Neck Surgery advises against routine vestibular function testing 1

4. Central Causes (stroke, TIA):

   • May present with vertigo and severe imbalance
   • Often has abnormal HINTS examination
   • Requires urgent neuroimaging

Common Pitfalls to Avoid

1. Focusing on the quality of dizziness rather than timing and triggers 1
2. Failing to perform the Dix-Hallpike maneuver in patients with positional vertigo 1
3. Routinely prescribing vestibular suppressants like meclizine for BPPV (may delay central compensation) 1, 2
4. Missing central causes by not performing HINTS examination 1
5. Ordering unnecessary imaging for clear peripheral vertigo 1
6. Overlooking medication side effects as potential causes of dizziness

Medication Considerations

When prescribing meclizine for vestibular vertigo:

• Dosage: 25 mg to 100 mg daily in divided doses 2
• Caution: May cause drowsiness; patients should avoid driving and alcohol 2
• Contraindicated in patients with hypersensitivity to meclizine 2
• Use with caution in patients with asthma, glaucoma, or prostate enlargement due to anticholinergic effects 2

Remember that pharmacologic intervention should be limited as it may affect central compensation for dizziness 3.