What is the differential diagnosis and management for a patient presenting with headache and lightheadedness?

Differential Diagnosis for Headache and Lightheadedness

The combination of headache and lightheadedness requires immediate exclusion of life-threatening secondary causes before considering primary headache disorders, with particular attention to cardiovascular, cerebrovascular, and intracranial pressure abnormalities that can present with both symptoms.

Life-Threatening Secondary Causes (Rule Out First)

Immediate Neuroimaging Required If:

• Subarachnoid hemorrhage: Thunderclap onset (worst headache of life), altered consciousness, neck stiffness, or focal neurological signs 1
• Stroke or TIA: Focal neurological deficits, atypical aura lasting >60 minutes, or sudden onset in patients >50 years 2, 1
• Meningitis/Encephalitis: Fever, neck stiffness, altered mental status, or immunocompromised state 1, 3
• Intracranial mass or increased ICP: Progressive worsening, worse with coughing/straining, personality changes, or papilledema 1, 4
• Cerebral hemorrhage: Sudden severe headache with altered consciousness or focal signs 2, 1

Cardiovascular Causes:

• Orthostatic hypotension: Lightheadedness worse within 2 hours of standing, improves >50% within 2 hours of lying flat; confirm with standing blood pressure showing drop >20 mmHg systolic or >10 mmHg diastolic 2
• Postural tachycardia syndrome (PoTS): Heart rate increase >30 bpm on standing with orthostatic symptoms; requires formal autonomic testing if standing test negative 2
• Cardiac arrhythmia: Palpitations, chest discomfort, or syncope accompanying symptoms 5, 6

Red Flags Requiring Urgent Evaluation:

• Age ≥50 years with new-onset headache 1, 4
• Headache after head trauma 1
• Headache worse with exertion or Valsalva 1, 4
• Presence of cancer or immunosuppression 7, 1
• Focal neurological signs or papilledema 1, 3

Primary Headache Disorders with Lightheadedness

Migraine (Most Common Primary Cause):

Suspect migraine without aura if patient has recurrent moderate-to-severe headache with at least two of: unilateral location, pulsating quality, moderate-to-severe intensity, or aggravation by routine activity; PLUS nausea/vomiting and/or photophobia/phonophobia 2

Suspect migraine with aura if above features plus fully reversible visual, sensory, speech, or motor symptoms spreading gradually over ≥5 minutes, lasting 5-60 minutes, with headache following within 60 minutes 2

• Lightheadedness in migraine may represent brainstem aura symptoms or associated autonomic dysfunction 2
• Family history of migraine strengthens diagnosis, particularly if onset at/around puberty 2
• Requires ≥5 attacks meeting criteria for diagnosis 2

Medication-Overuse Headache:

Suspect if headache occurs ≥15 days/month in patient with pre-existing headache disorder AND regular overuse >3 months of acute medications (non-opioid analgesics ≥15 days/month OR triptans/combination medications ≥10 days/month) 2, 8

• Must rule out MOH before initiating preventive therapy, as it prevents treatment response 8
• Requires withdrawal of overused medication (abrupt withdrawal preferred except for opioids) 2, 8

Chronic Migraine:

Diagnose if headache ≥15 days/month for >3 months, with migraine features on ≥8 days/month 2, 8

Secondary Headache Disorders Specific to This Presentation

Spontaneous Intracranial Hypotension (SIH):

Suspect if headache is absent/mild (1-3/10) on waking, onset within 2 hours of becoming upright, and improves >50% within 2 hours of lying flat with consistent timing 2

• Differentiate from PoTS and orthostatic hypotension with formal standing tests 2
• Associated symptoms include neck pain, tinnitus, hearing changes, nausea, and photophobia 2
• Requires MRI brain with contrast showing pachymeningeal enhancement or brain sagging for diagnosis 2

Cervicogenic Headache:

Diagnose if headache provoked by cervical movement (not posture), reduced cervical range of motion, and myofascial tenderness in presence of cervical pathology 2

Tension-Type Headache:

Bilateral, mild-to-moderate pressing/tightening quality, NOT aggravated by routine activity, lacking migraine-associated symptoms 2, 7

• Less likely to cause significant lightheadedness unless accompanied by anxiety 7

Diagnostic Approach Algorithm

Step 1: Exclude Emergency Conditions

• Perform focused neurological examination: cranial nerves, motor/sensory function, cerebellar testing, neck stiffness 1, 3
• Check vital signs including orthostatic blood pressure and heart rate 2, 1
• If ANY red flags present: Non-contrast head CT if <6 hours from acute onset; MRI brain with/without contrast for subacute presentations 1, 4
• If thunderclap headache with negative CT: Lumbar puncture to exclude subarachnoid hemorrhage 1

Step 2: Characterize Headache Pattern

• Duration of episodes (migraine: 4-72 hours untreated) 2
• Frequency (chronic migraine: ≥15 days/month) 2, 8
• Quality (pulsating vs. pressing) 2
• Location (unilateral vs. bilateral) 2
• Aggravating factors (movement vs. posture vs. routine activity) 2

Step 3: Assess Orthostatic Component

• Document timing: Does headache/lightheadedness occur within 2 hours of standing? 2
• Document relief: Does it improve >50% within 2 hours of lying flat? 2
• Perform standing test: Measure BP and HR supine, then at 1,3,5, and 10 minutes standing 2

Step 4: Identify Accompanying Symptoms

• Nausea, vomiting, photophobia, phonophobia (suggests migraine) 2
• Aura symptoms (visual, sensory, speech disturbances) 2
• Autonomic symptoms (lacrimation, nasal congestion—suggests cluster headache) 2

Step 5: Medication History

• Acute medication use frequency (≥10-15 days/month suggests MOH) 2, 8
• Duration of regular overuse (>3 months required for MOH) 2

Management Considerations

If Primary Headache Confirmed:

• Limit acute medication to ≤2 days/week to prevent medication overuse headache 8
• First-line acute treatment: NSAIDs plus antiemetics for nausea 8, 7
• Migraine-specific acute treatment: Triptans eliminate pain in 20-30% at 2 hours but contraindicated in cardiovascular disease due to vasoconstrictive properties 5, 6, 7
• Consider preventive therapy if adversely affected ≥2 days/month despite optimized acute treatment 2, 8

Preventive Medication Algorithm:

1. First-line: Beta-blockers (propranolol, metoprolol), topiramate, or candesartan 2, 8
2. Second-line: Flunarizine, amitriptyline (especially if comorbid depression/sleep disturbance), or valproate (contraindicated in women of childbearing potential) 2
3. Third-line: CGRP monoclonal antibodies after failure of ≥2-3 other preventives 2, 8

Specialist Referral Indications:

• Confirmed chronic migraine diagnosis 8
• Diagnostic uncertainty or atypical features 2, 9
• Failure of multiple preventive medications 8
• Persistent aura or associated motor weakness 9
• Consideration of onabotulinumtoxinA or CGRP antibodies 8
• Suspected SIH requiring epidural blood patch 2

Critical Pitfalls to Avoid

• Do not dismiss lightheadedness as benign anxiety without cardiovascular evaluation, as it may represent orthostatic hypotension, PoTS, or cardiac arrhythmia requiring specific treatment 2
• Do not initiate preventive therapy without first ruling out and treating MOH, as medication overuse prevents response to preventive medications 2, 8
• Do not allow unlimited acute medication use; strict limitation to twice weekly prevents progression to chronic migraine and MOH 8
• Do not miss giant cell arteritis in patients >50 years with new-onset headache, as delay causes permanent vision loss 10
• Do not rely solely on imaging without complete clinical assessment including temporal relationship of symptoms and orthostatic vital signs 2, 1
• Do not use triptans in patients with cardiovascular disease or risk factors without cardiovascular evaluation due to coronary vasospasm risk 5, 6, 7