What is the differential diagnosis for a patient presenting with daily headaches and dizziness?

Differential Diagnosis for Daily Headache with Dizziness

The differential diagnosis for daily headaches with dizziness must first exclude secondary causes through careful history and examination for "red flags," then systematically consider primary headache disorders—particularly chronic migraine and vestibular migraine—alongside peripheral and central vestibular disorders. 1, 2

Initial Critical Step: Rule Out Secondary Causes

Before considering primary headache disorders, you must evaluate for secondary causes that could threaten morbidity and mortality. 1, 3

Red Flags Requiring Urgent Evaluation:

• Focal neurological deficits (diplopia, dysarthria, numbness, weakness) 1, 4
• Sudden severe headache ("thunderclap" or "first/worst" headache) 3, 5
• Sudden hearing loss 4
• Inability to stand or walk 4
• Downbeating nystagmus or other central nystagmus patterns 4
• New-onset headache in patients over age 50 (consider temporal arteritis, stroke, neoplasm, subdural hematoma) 6

If any red flags are present, neuroimaging with MRI brain (preferred over CT) is indicated immediately. 2, 4

Primary Differential Diagnoses

1. Chronic Migraine

Chronic migraine is defined as ≥15 headache days per month for ≥3 months, with ≥8 days meeting migraine criteria (unilateral, pulsating, moderate-to-severe intensity, aggravated by activity, with nausea/vomiting or photophobia/phonophobia). 1

• Each headache must last ≥4 hours 1
• Dizziness can occur as a non-specific associated symptom 7
• Only 20% of patients meeting criteria are correctly diagnosed 1
• Ask specifically: "Do you feel like you have a headache of some type on 15 or more days per month?" 1

2. Vestibular Migraine

Vestibular migraine presents with ≥5 episodes of moderate-to-severe vestibular symptoms (vertigo, dizziness) lasting 5 minutes to 72 hours, with migraine features (headache with migraine characteristics, photophobia/phonophobia, or visual aura) occurring in ≥50% of episodes. 1

• Requires current or previous history of migraine 1
• Headache, photophobia, and phonophobia suggest this diagnosis 4
• Vestibular symptoms may occur before, during, or after headache 1
• This is a common cause of dizziness that closely mimics Ménière's disease 1

3. Chronic Tension-Type Headache

Bilateral, pressing/tightening (non-pulsating) quality, mild-to-moderate intensity, not aggravated by routine physical activity, occurring ≥15 days per month for >3 months. 1

• Dizziness is less commonly associated but can occur 7
• Lacks the migraine-associated features 8

4. New Daily Persistent Headache

Daily, unremitting headache from onset (or within 3 days), clearly remembered by patient, present for >3 months. 1

• Patient can pinpoint exact date headache began 1
• Dizziness may be a concurrent symptom 7

5. Hemicrania Continua

Continuous unilateral headache with exacerbations, responsive to indomethacin, may have autonomic features. 1

Peripheral Vestibular Disorders to Consider

6. Ménière's Disease

Episodic vertigo lasting 20 minutes to 12 hours, with fluctuating hearing loss, tinnitus, and aural fullness. 1, 4

• Associated symptoms include hearing loss or tinnitus 1, 2
• Can closely mimic vestibular migraine 1

7. Benign Paroxysmal Positional Vertigo (BPPV)

Brief episodes (seconds to minutes) of vertigo triggered by specific head movements. 2, 4

• Perform Dix-Hallpike maneuver and supine roll test 2, 4
• Headache may be a concurrent but separate issue 7

Diagnostic Approach Algorithm

Step 1: Timing and Trigger Classification

Categorize dizziness by timing rather than patient's subjective description: 2, 4

• Acute vestibular syndrome (days to weeks of constant symptoms) 2, 4
• Triggered episodic (seconds to minutes with positional triggers) 2, 4
• Spontaneous episodic (minutes to hours without triggers) 2, 4
• Chronic vestibular syndrome (persistent symptoms >3 months) 4

Step 2: Physical Examination

Observe for spontaneous nystagmus in all patients 2, 4

For suspected BPPV, perform positional testing 2, 4

For acute vestibular syndrome, perform HINTS examination (Head Impulse, Nystagmus, Test of Skew) if trained—this is more sensitive than early MRI for posterior circulation stroke (100% vs 46% sensitivity) 4

Step 3: Imaging Decisions

Imaging is NOT routinely indicated for most cases of dizziness with headache 2, 4

MRI brain is indicated when: 2, 4

• Abnormal neurological examination present
• HINTS examination suggests central cause
• High vascular risk with acute vestibular syndrome
• Unilateral tinnitus or asymmetric hearing loss
• Pulsatile tinnitus

Critical Pitfalls to Avoid

Do not rely on patient descriptions of "spinning" versus "lightheadedness"—focus on timing and triggers instead 4

Do not assume a normal neurologic exam excludes stroke—75-80% of patients with posterior circulation infarct from acute vestibular syndrome have no focal neurologic deficits 4

Do not overuse imaging in patients with clear peripheral causes or typical primary headache patterns 2, 4

Do not use CT instead of MRI when stroke is suspected—CT misses many posterior circulation infarcts 4

Do not miss medication overuse headache as a contributing factor in chronic daily headache 1