Is an electroencephalogram (EEG) indicated in a patient with dizziness, vertigo, and headache for four days?

EEG in Dizziness and Vertigo with Headache

EEG is not indicated in a patient with dizziness, vertigo, and headache for four days unless there are specific signs suggesting epilepsy or encephalitis. 1, 2

Diagnostic Approach for Dizziness with Headache

Initial Assessment

• Focus on timing, triggers, and associated symptoms rather than quality of dizziness
• Evaluate for vestibular syndromes:
  • Acute Vestibular Syndrome (AVS)
  • Triggered Episodic Vestibular Syndrome
  • Spontaneous Episodic Vestibular Syndrome
  • Chronic Vestibular Syndrome 2

When EEG Is Not Indicated

• European Heart Journal guidelines clearly state that EEG is "not recommended for patients in whom syncope is a priori the most likely cause for a transient loss of consciousness" 1
• EEG has limited utility in unselected patients with dizziness or syncope 1
• No specific EEG findings exist for any loss of consciousness other than epilepsy 1

When EEG May Be Indicated

1. Suspected seizures or epilepsy:

   • History of witnessed seizure activity
   • Stereotyped episodes with post-ictal confusion
   • Tongue biting or urinary incontinence during episodes 1

2. Suspected autoimmune encephalitis:

   • EEG can confirm focal/multifocal brain abnormality
   • Rule out subclinical seizures in encephalopathic patients
   • Monitor treatment response in patients with seizures 1

3. New onset refractory status epilepticus (NORSE):

   • Can be convulsive or non-convulsive
   • EEG findings may include focal slowing/seizures or lateralized periodic discharges 1

More Appropriate Diagnostic Tests

For Vestibular Assessment

• HINTS examination: More sensitive than early MRI (100% vs 46%) for detecting stroke in isolated vertigo 2
• Dix-Hallpike maneuver: Gold standard for diagnosing posterior canal BPPV 2
• Supine roll test: For lateral semicircular canal BPPV 2

For Suspected Vestibular Migraine

• Vestibular migraine is the most common cause of spontaneous episodic vertigo 3
• Consider using the Vestibular Migraine Patient Assessment Tool and Handicap Inventory (VM-PATHI) 3

Neuroimaging When Indicated

• MRI brain (without contrast) is preferred when central causes are suspected:
  • Acute Vestibular Syndrome with abnormal HINTS examination
  • Presence of neurological deficits
  • High vascular risk patients 2

Common Pitfalls to Avoid

1. Overreliance on EEG: Several studies have conclusively shown that EEG monitoring has little use in unselected patients with dizziness or syncope 1

2. Missing red flags requiring urgent evaluation:

   • Sudden severe headache
   • New neurological symptoms
   • Inability to walk or stand
   • Persistent vomiting
   • Altered mental status 2

3. Failure to consider vestibular migraine: Often overlooked as a common cause of dizziness with headache 3, 4

In conclusion, while EEG may occasionally reveal epileptiform abnormalities in patients with dizziness and headache, it should be reserved for cases with specific clinical features suggesting epilepsy or encephalitis rather than used routinely in the evaluation of dizziness with headache.