What is the approach to evaluating dizziness?

Approach to Evaluating Dizziness

The evaluation of dizziness should focus on categorizing symptoms by timing, triggers, and associated features, with specific diagnostic maneuvers like the Dix-Hallpike test for vertigo and HINTS examination for acute vestibular syndrome, rather than relying on routine imaging. 1

Initial 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
2. Disequilibrium: Imbalance or unsteadiness
3. Presyncope: Near-fainting sensation
4. Lightheadedness: Vague sensation of disconnection

Key Diagnostic Features to Assess

• Timing: Duration of episodes (seconds, minutes, hours, days)
• Triggers: Positional changes, standing, exertion
• Associated symptoms: Hearing loss, tinnitus, neurological deficits, headache

Diagnostic Approach by Dizziness Type

For Vertigo

1. Assess for nystagmus:

   • Direction, duration, and triggers

2. Perform Dix-Hallpike maneuver for suspected BPPV:

   • Positive test: Brief vertigo with characteristic nystagmus
   • If positive, proceed with Canalith Repositioning Procedure (Epley maneuver) which has 80% success rate 1

3. For acute severe vertigo, perform HINTS examination:

   • Head-Impulse test
   • Nystagmus assessment
   • Test of Skew
   • Abnormal HINTS suggests central cause requiring MRI 1, 2

For Presyncope

1. Measure orthostatic blood pressure:

   • Diagnostic drop: ≥20 mmHg systolic or ≥10 mmHg diastolic within 3 minutes of standing 1

2. Review medication list for potential causes 3

For Disequilibrium

1. Perform neurological examination focusing on:

   • Gait assessment
   • Coordination testing
   • Proprioception evaluation

2. Consider validated assessment tools:

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

For Lightheadedness

1. Screen for psychiatric conditions:
   • Anxiety
   • Depression
   • Hyperventilation syndrome 3

Imaging and Additional Testing

Imaging is NOT routinely indicated for isolated dizziness without neurological deficits 1

MRI brain (without contrast) is indicated only 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

CT scan of the head is indicated when vertigo is accompanied by:

• Severe headache
• Age >60 years with risk factors
• Vomiting
• Drug/alcohol intoxication
• Short-term memory deficits
• Trauma above the clavicle
• Seizures
• Focal neurological deficits 1

Common Diagnoses and Management

BPPV

• Presentation: Brief vertigo with position changes
• Diagnosis: Positive Dix-Hallpike test
• Treatment: Canalith Repositioning Procedure (Epley maneuver) 1, 2

Vestibular Neuritis

• Presentation: Sudden severe vertigo with prolonged nausea, no hearing loss
• Diagnosis: Unidirectional horizontal nystagmus, normal HINTS exam
• Treatment: Early corticosteroid therapy 1

Menière's Disease

• Presentation: Episodic vertigo with hearing loss, tinnitus, aural fullness
• Treatment: Intratympanic dexamethasone or gentamicin may be considered 3

Orthostatic Hypotension

• Treatment: Medication adjustment, hydration, compression stockings, gradual position changes 1

Pharmacological Management

Meclizine is indicated specifically for vertigo associated with diseases affecting the vestibular system in adults 4. However, vestibular suppressants should not be routinely prescribed for BPPV as they may delay central compensation 1.

Common Pitfalls to Avoid

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

Special Considerations

• Approximately 20% of dizziness cases may remain undiagnosed despite thorough evaluation 3, 5
• Commercial drivers with dizziness require comprehensive evaluation due to public safety concerns 1
• Vestibular rehabilitation is effective for persistent dizziness after BPPV resolution 1, 2