What are the differential diagnoses and management options for a patient presenting with headache and blurred vision?

Differential Diagnosis for Headache and Blurred Vision

The most critical initial step is fundoscopic examination to identify papilledema, which indicates increased intracranial pressure requiring urgent neuroimaging and potential neurosurgical intervention. 1

Immediate Red Flag Assessment

The following life-threatening conditions must be ruled out first:

• Increased intracranial pressure from mass lesion, idiopathic intracranial hypertension, or cerebral venous thrombosis—look for papilledema on fundoscopy, which appears as optic disc swelling with blurred margins and venous engorgement 2, 1
• Acute angle-closure glaucoma—presents with severe eye pain, halos around lights, mid-dilated poorly reactive pupil, corneal edema, and intraocular pressure >40 mmHg 2, 1
• Giant cell arteritis (if age >50)—check ESR and CRP immediately, as this can cause irreversible vision loss 1
• Intracranial mass or tumor—especially if symptoms are progressive or associated with focal neurologic deficits 1
• Optic neuritis—classic triad of unilateral eye pain (worse with eye movement), subacute vision loss, and impaired color vision in young adults 3

Essential Physical Examination Elements

Perform these specific examinations systematically:

• Fundoscopic examination: Identify papilledema (disc swelling, blurred margins), venous engorgement ("sausaging" of retinal veins), or optic disc pallor 2, 1
• Pupil examination: Assess size (mid-dilated in angle closure), shape (oval/irregular suggests acute pathology), reactivity (poor in angle closure or after attack), and relative afferent pupillary defect (indicates optic nerve or severe retinal disease) 2, 1
• Visual acuity testing: Document baseline vision in each eye separately 1
• Visual field assessment by confrontation: Central scotoma suggests optic neuritis; altitudinal defect suggests ischemic optic neuropathy 1, 3
• Intraocular pressure measurement: If angle-closure suspected based on symptoms (halos, severe pain, corneal edema) 2, 1

Age-Specific Risk Stratification

Patients over 50 years old with new-onset headache and vision changes require immediate neuroimaging, as this age group has substantially higher risk of tumor, stroke, subdural hematoma, and giant cell arteritis 1

Younger patients, especially overweight females of childbearing age, should raise suspicion for idiopathic intracranial hypertension 1

Neuroimaging Protocol

MRI brain with and without gadolinium contrast is the mandatory initial imaging study for patients with headache and blurred vision, as it provides superior detection of structural lesions, tumors, demyelination, vascular abnormalities, optic nerve pathology, empty sella, dilated optic sheaths, and posterior globe flattening without radiation exposure 1

CT head without contrast may substitute only if MRI is unavailable or contraindicated, though it is significantly less sensitive for critical diagnoses 1

Laboratory Testing

Order these tests based on clinical presentation:

• ESR and CRP (mandatory if age >50) to exclude giant cell arteritis 1
• Basic metabolic panel including glucose, sodium, and renal function 1
• Complete blood count in select cases based on clinical suspicion 1

Urgent Ophthalmology Referral Indications

Refer immediately for:

• Papilledema identified on fundoscopy—poses risk of permanent vision loss 1
• Suspected acute angle-closure glaucoma—mid-dilated pupil, corneal edema, very high IOP, severe eye pain 2, 1
• Uveitis or inflammatory eye disease—eye pain, photophobia, anterior chamber cells 1

Common Differential Diagnoses by Pattern

Headache with Bilateral Blurred Vision

• Migraine with aura: Preceded by visual symptoms (scintillating scotoma, zigzag lines), responds to triptans or NSAIDs; prochlorperazine 25 mg orally or suppository can be used as adjunctive therapy 2
• Medication side effects: Ibuprofen and other NSAIDs can cause blurred vision, scotomata, and color vision changes—discontinue drug if this occurs 4
• Hyperviscosity syndrome (Waldenström's macroglobulinaemia): Look for fundoscopic "sausaging" of retinal veins; more reliable than serum viscosity measurement 2
• Autonomic dysreflexia (in spinal cord injury patients): Presents with headache, blurred vision, flushing, sweating, and sense of impending doom; systolic BP >150 mmHg or >20 mmHg above baseline 2

Headache with Unilateral Blurred Vision

• Optic neuritis: Unilateral eye pain worsening with eye movement, subacute vision loss over days, impaired color vision disproportionate to visual acuity loss; requires MRI orbits and brain with contrast 3
• Anterior uveitis: Can present with headache, blurred vision, and elevated IOP; look for mutton-fat keratic precipitates and anterior chamber cells on slit lamp examination 5

Critical Pitfalls to Avoid

• Do not attribute symptoms to migraine without fundoscopic examination—missing papilledema can result in permanent vision loss 1
• Do not delay neuroimaging in patients >50 years old with new-onset symptoms 1
• Do not continue NSAIDs if patient develops blurred vision or scotomata—this is a known adverse effect requiring drug discontinuation and ophthalmologic examination including central visual fields and color vision testing 4
• Do not miss medication-induced causes: Midodrine (used in hepatorenal syndrome) can cause headaches and blurred vision; octreotide can cause headaches 2

Management Algorithm

1. Perform fundoscopic examination immediately 1
2. If papilledema present: Order urgent MRI brain with/without contrast and refer to neurology/neurosurgery same day 1
3. If acute angle-closure suspected (mid-dilated pupil, corneal edema, severe pain): Measure IOP and refer to ophthalmology emergently 2, 1
4. If age >50: Check ESR/CRP for giant cell arteritis and order MRI brain 1
5. If unilateral with eye pain: Consider optic neuritis; order MRI orbits and brain with contrast 3
6. If examination normal and age <50: Consider migraine; trial NSAIDs (ibuprofen 400-800 mg) or triptans with metoclopramide 10 mg as adjunctive therapy 2