What is the approach to a comprehensive dizziness workup?

Comprehensive Dizziness Workup

A systematic dizziness workup should begin by categorizing the dizziness by timing and triggers rather than symptom quality, followed by targeted physical examination including the HINTS test for acute vestibular syndrome to distinguish between benign peripheral causes and potentially life-threatening central causes. 1

Step 1: Categorize the Dizziness by Timing and Triggers

Categorize the patient's dizziness into one of four vestibular syndromes:

1. Acute Vestibular Syndrome (AVS)

   • Continuous dizziness lasting days to weeks
   • Associated with nausea, vomiting, head motion intolerance
   • Common causes: Vestibular neuritis, labyrinthitis, posterior circulation stroke 1

2. Triggered Episodic Vestibular Syndrome

   • Brief episodes triggered by specific actions (typically <1 minute)
   • Common causes: Benign Paroxysmal Positional Vertigo (BPPV), central paroxysmal positional vertigo 1

3. Spontaneous Episodic Vestibular Syndrome

   • Episodes not triggered by specific actions, lasting minutes to hours
   • Common causes: Vestibular migraine, Ménière's disease, TIA 1

4. Chronic Vestibular Syndrome

   • Dizziness lasting weeks to months
   • Common causes: Anxiety, medication side effects, posterior fossa masses 1

Step 2: Targeted Physical Examination

For Acute Vestibular Syndrome:

• Perform the HINTS examination (Head-Impulse, Nystagmus, Test of Skew)
  • Head-Impulse: Abnormal in peripheral causes, normal in central causes
  • Nystagmus: Direction-changing in central causes, unidirectional in peripheral causes
  • Test of Skew: Present in central causes, absent in peripheral causes
  • HINTS+ adds hearing assessment (unilateral hearing loss suggests peripheral cause) 1

For Triggered Episodic Vestibular Syndrome:

• Perform the Dix-Hallpike maneuver to diagnose posterior canal BPPV 2

  • Positive test: Delayed onset (latency) of vertigo and nystagmus after position change
  • Nystagmus is upbeating and torsional, lasting <60 seconds
  • Symptoms fatigue with repeated testing

• If Dix-Hallpike is negative but history suggests BPPV, perform the supine roll test for lateral canal BPPV 2

  • Observe for geotropic nystagmus (beating toward the ground) or apogeotropic nystagmus (beating away from the ground)

For All Patients:

• Complete neurological examination
• Orthostatic blood pressure measurement
• Cardiac examination
• Otologic examination (including hearing assessment) 3

Step 3: Diagnostic Testing

Imaging:

• MRI head without IV contrast is indicated for:

  • AVS with abnormal HINTS exam or neurological deficits
  • High vascular risk patients with AVS even with normal exam
  • Not routinely indicated for typical BPPV with positive Dix-Hallpike 1

• CT head without IV contrast:

  • Less sensitive than MRI, especially for posterior fossa lesions
  • Consider when MRI is not immediately available for high-risk patients
  • Low yield (<1%) in isolated dizziness without neurological deficits 1

Vestibular Testing:

• Should not be ordered in patients who meet diagnostic criteria for BPPV in the absence of additional vestibular signs/symptoms 2
• May be beneficial when:
  • Clinical presentation is atypical
  • Dix-Hallpike testing elicits equivocal or unusual nystagmus
  • Diagnosis is unclear
  • Additional symptoms suggest CNS or otologic disorder
  • Multiple concurrent peripheral vestibular disorders are suspected 2

Laboratory Testing:

• Generally plays a limited role in diagnosis 3
• Consider basic metabolic panel, CBC, and thyroid function tests if metabolic causes are suspected

Step 4: Treatment Based on Diagnosis

BPPV:

• Canalith Repositioning Procedures (CRP):
  • Epley maneuver for posterior canal BPPV
  • Modified Epley or Gufoni maneuver for lateral canal BPPV 2

Vestibular Neuritis/Labyrinthitis:

• Steroids for vestibular neuritis 4
• Vestibular rehabilitation

Ménière's Disease:

• Low-salt diet, diuretics
• Intratympanic dexamethasone or gentamicin for refractory cases 4

Vertigo Associated with Vestibular System Diseases:

• Meclizine for symptomatic relief 5

Step 5: Follow-up and Patient Education

• Counsel patients with BPPV regarding:

  • Impact on safety
  • Potential for disease recurrence (15% per year, up to 50% at 5 years)
  • Importance of follow-up 2

• For persistent symptoms:

  • Reevaluate for correct diagnosis
  • Consider CNS disorders that can masquerade as BPPV (3% of treatment failures) 2
  • Consider vestibular rehabilitation

Important Pitfalls to Avoid:

1. Don't rely solely on symptom quality descriptions (vertigo, lightheadedness) as these are often unreliable; focus on timing and triggers instead 1

2. Don't miss posterior circulation stroke which can present with isolated dizziness in up to 25% of cases (75% in high vascular risk patients) 1

3. Don't routinely order neuroimaging for patients with typical BPPV and positive Dix-Hallpike test 2

4. Don't forget to repeat the Dix-Hallpike maneuver at a separate visit if initially negative but clinical suspicion for BPPV remains high 2

5. Don't overlook medication side effects as a common cause of dizziness, especially in elderly patients 4