Is an electroencephalogram (EEG) indicated in a patient presenting with dizziness and vertigo of recent onset, specifically four days?

EEG is Not Indicated for Dizziness and Vertigo of Recent Onset

EEG is not indicated in the standard diagnostic workup for a patient presenting with dizziness and vertigo of four days duration unless there are specific neurological symptoms suggesting seizure activity. 1

Diagnostic Approach for Dizziness and Vertigo

The diagnostic approach for dizziness should follow a systematic evaluation based on the clinical presentation:

Initial Assessment

• Categorize the dizziness into one of four vestibular syndromes:
  • Acute Vestibular Syndrome (AVS)
  • Triggered Episodic Vestibular Syndrome
  • Spontaneous Episodic Vestibular Syndrome
  • Chronic Vestibular Syndrome 1

Recommended Diagnostic Tests

1. HINTS examination - Most effective method for differentiating stroke from benign peripheral causes (more sensitive than early MRI) 1
2. Dix-Hallpike maneuver - Gold standard for diagnosing posterior canal BPPV 1
3. Supine roll test - For lateral semicircular canal BPPV 1
4. Audiogram - Essential for evaluating hearing loss associated with conditions like Ménière's disease 1
5. Video/electronystagmogram - Evaluates vestibular function 1

Neuroimaging Indications

• MRI brain (without contrast) is indicated when:
  • Acute Vestibular Syndrome with abnormal HINTS examination
  • Neurological deficits are present
  • Patient has high vascular risk factors
  • Chronic undiagnosed dizziness not responding to treatment 1

When EEG Should Be Considered

EEG is not part of the standard workup for dizziness and vertigo. According to guidelines, EEG should only be considered in specific situations:

1. Suspected seizure activity - When vertigo is accompanied by other seizure symptoms 2
2. Nonconvulsive status epilepticus - In patients with altered consciousness 2
3. Subtle convulsive status epilepticus - When motor manifestations are minimal 2

Epileptic Vertigo and Dizziness (EVD)

Research shows that epileptic vertigo is rare, particularly as an isolated symptom:

• Isolated epileptic vertigo/dizziness occurs in only 0.8% of cases 3
• Non-isolated epileptic vertigo (accompanied by other seizure symptoms) is more common at 8.5% 3
• Epileptic vertigo is primarily associated with temporal lobe seizures 3, 4
• Isolated epileptic vertigo typically presents with very brief episodes (<30 seconds) 3

Key Distinguishing Features of Epileptic Vertigo

• Very brief episodes (seconds rather than days)
• Association with other seizure symptoms
• EEG abnormalities (typically temporal lobe) 4, 5

Cost-Utility Considerations

Neuroimaging studies for vertigo and dizziness often yield low diagnostic yield:

• CT scans identify the cause in only 5% of vertigo cases 6
• MRI of the inner ear and cerebellopontine angle has higher yield (17.7%) 6
• Indiscriminate use of neuroimaging is not cost-effective 6

Conclusion

For a patient with dizziness and vertigo of four days duration, the diagnostic approach should focus on vestibular testing and targeted neuroimaging when indicated. EEG should only be considered if there are specific features suggesting seizure activity, such as altered consciousness, brief episodic nature (<30 seconds), or associated seizure symptoms. The standard workup should include a thorough vestibular examination including HINTS, Dix-Hallpike, and other vestibular tests before considering EEG.