Differential Diagnosis of Headache with Dizziness
The differential diagnosis for headache with dizziness must first distinguish between primary headache disorders (migraine, tension-type headache, cluster headache) and life-threatening secondary causes (subarachnoid hemorrhage, meningitis, stroke), while also considering vestibular migraine, spontaneous intracranial hypotension, and autonomic disorders as key diagnostic possibilities.
Algorithmic Approach to Diagnosis
Step 1: Rule Out Life-Threatening Secondary Causes
Look for red flags that mandate immediate investigation 1:
- Thunderclap headache (consider subarachnoid hemorrhage first, then spontaneous intracranial hypotension if followed by orthostatic features) 2
- Unexplained fever
- Impaired memory or altered consciousness
- Focal neurological deficits
- Atypical aura
- Recent head trauma
If red flags present: Obtain neuroimaging (CT/MRI), blood work, or lumbar puncture as indicated 1.
Step 2: Characterize the Headache Pattern
Orthostatic Features Present?
If headache is absent or mild (1-3/10) on waking, develops within 2 hours of standing, and improves >50% within 2 hours of lying flat with consistent timing 2:
Primary consideration: Spontaneous Intracranial Hypotension (SIH)
- Associated symptoms may include neck pain, tinnitus, hearing changes
- Refer to neurology within 2-4 weeks if self-caring; within 48 hours if not 2
Differential diagnoses for orthostatic symptoms:
- Postural Tachycardia Syndrome (PoTS): Heart rate increases >30 bpm on standing
- Orthostatic hypotension: Systolic BP drops >20 mmHg or diastolic >10 mmHg on standing
- Perform formal standing tests to confirm 2
Episodic Vertigo/Dizziness with Headache?
Primary consideration: Vestibular Migraine 3, 4, 5
- Most common cause of spontaneous episodic vertigo
- Vestibular episodes last seconds to days
- Temporal association between migraine symptoms and vestibular episodes in ≥50% of attacks
- May include transient auditory symptoms, nausea, motion sickness susceptibility
- Key distinction: Provoked by movement, NOT posture 2
Must differentiate from:
- Menière's disease: Hearing loss and tinnitus predominate over vertigo 4
- Benign paroxysmal positional vertigo (BPPV): Brief episodes (<1 minute) triggered by specific head positions
- Vestibular neuritis: Single prolonged episode, no headache
- Posterior circulation stroke: Focal neurological signs, vascular risk factors 6
Step 3: Evaluate Primary Headache Disorders
Migraine 1
Use ID-Migraine screening (sensitivity 0.81, specificity 0.75):
- Photophobia present?
- Nausea present?
- Disability from headache?
Features: Unilateral or bilateral, pulsating, moderate-severe intensity, aggravated by routine physical activity, accompanied by nausea and/or photophobia/phonophobia
Tension-Type Headache 1
- Bilateral, mild-moderate intensity
- Pressing/tightening quality
- NOT aggravated by physical activity
- Lacks migraine-associated symptoms
Cluster Headache 1
- Strictly unilateral, severe-very severe intensity
- Short duration (15-180 minutes)
- Ipsilateral autonomic symptoms (lacrimation, conjunctival injection, nasal congestion)
- Dizziness is NOT a typical feature
Step 4: Consider Cervicogenic Headache
If cervical pathology suspected 2:
- Headache provoked by cervical movement (not posture)
- Reduced cervical range of motion
- Myofascial tenderness
- Key distinction: Movement-provoked, not posture-provoked
Step 5: Evaluate for Medication Overuse Headache
If chronic daily headache present 1:
- Important differential for chronic migraine
- History of frequent acute medication use (≥10-15 days/month depending on medication type)
Step 6: Screen for Hypertensive Headache
Only if BP ≥180/120 mmHg 7:
- Must demonstrate temporal association between elevated BP and headache
- Symptom relief with antihypertensive treatment
- Exclude primary headache disorders first
- Severe hypertension with headache requires urgent evaluation for malignant hypertension
Step 7: Consider Non-Neurological Causes 6
- Drug side-effects or intoxication
- Electrolyte disturbances
- Cardiac disease (arrhythmias, valvular disease)
- Severe anemia
- Endocrine disorders (thyroid dysfunction)
- Carbon monoxide poisoning
Critical Pitfalls to Avoid
- Do not assume hypertension causes headache/dizziness unless BP ≥180/120 mmHg and diagnostic criteria met 7
- Do not order neuroimaging routinely—only when red flags present 1
- Do not miss spontaneous intracranial hypotension—specifically ask about postural variation 2
- Do not confuse dizziness (lightheadedness) with vertigo (illusion of movement)—this distinction guides differential diagnosis 7
- Vestibular migraine is underdiagnosed—maintain high index of suspicion in patients with episodic vertigo and migraine history 4, 5
When Diagnosis Remains Unclear
Use headache diaries to document frequency, intensity, duration, associated symptoms, and medication use over 2-4 weeks 1. This often clarifies the diagnosis when initial evaluation is equivocal.