Amaurosis fugax

Central retinal artery occlusion is sudden, painless, profound monocular vision loss from embolic or thrombotic occlusion of the central retinal artery, an ocular stroke equivalent in which irreversible retinal infarction begins around 90 minutes after complete occlusion. Diagnosis is clinical on dilated fundoscopy, and management pairs time-critical reperfusion attempts with an emergency embolic and giant-cell-arteritis workup to protect the fellow eye and prevent a subsequent stroke.

Carotid artery stenosis is atherosclerotic narrowing of the extracranial internal carotid artery that raises ischemic stroke risk, graded by percent luminal narrowing on duplex ultrasound. Symptomatic stenosis of at least 50% warrants urgent revascularization; asymptomatic stenosis under 80% is managed with best medical therapy alone, including a high-intensity statin and antiplatelet agent.

Ischemic stroke is sudden focal neurologic deficit from arterial occlusion confirmed by infarction on neuroimaging. Diagnosis relies on urgent noncontrast head CT to exclude hemorrhage; treatment is IV alteplase within 4.5 hours and mechanical thrombectomy for large-vessel occlusion within an extended window, followed by antiplatelet therapy and risk-factor control.

Atrial fibrillation is a supraventricular tachyarrhythmia with disorganized atrial activation and an irregularly irregular ventricular response, the most common sustained arrhythmia and a major cause of stroke. Diagnosis is by ECG showing no discrete P waves with irregular RR intervals, and management addresses rate or rhythm control, stroke prevention by CHA2DS2-VASc-guided anticoagulation, and the underlying cause.

Giant cell arteritis is a granulomatous large- and medium-vessel vasculitis of patients over 50 that threatens irreversible blindness through ischemic optic neuropathy. Diagnosis is clinical and must not delay treatment: start high-dose glucocorticoids immediately on suspicion, intravenous methylprednisolone pulse for visual loss, then confirm with temporal artery biopsy within 1 to 2 weeks and add tocilizumab as glucocorticoid-sparing therapy.

Carotid artery dissection is a tear in the wall of the internal carotid artery creating an intramural hematoma, typically presenting with unilateral head, face, or neck pain, partial Horner syndrome, and ischemic stroke or transient ischemic attack in a young or middle-aged patient. Diagnosis is by MRA or CTA of the neck, and most patients are treated with antiplatelet or anticoagulant therapy.

Optic neuritis is inflammatory demyelination of the optic nerve, usually a presenting event of multiple sclerosis, causing subacute painful monocular vision loss with a relative afferent pupillary defect. Confirm with MRI orbits/brain and treat with IV methylprednisolone followed by an oral prednisone taper, never oral prednisone alone.

Acute angle-closure glaucoma is a pupillary-block emergency in which sudden closure of the iridocorneal angle blocks aqueous outflow, causing severe eye pain, halos, and rapidly rising intraocular pressure that can blind the eye within hours if not treated. Diagnosis is clinical plus tonometry and gonioscopy; treatment is immediate topical and systemic IOP-lowering therapy followed by laser peripheral iridotomy.

Migraine is a primary episodic headache disorder diagnosed by ICHD-3 clinical criteria (recurrent attacks, 4-72 hours, pulsatile/unilateral pain with nausea or photophobia/phonophobia). First-line acute treatment is an NSAID or oral triptan started early in the attack; prevention with a beta-blocker, topiramate, or CGRP-targeted therapy is added once attacks are frequent or disabling.

Antiphospholipid syndrome is an acquired autoimmune thrombophilia in which antiphospholipid antibodies cause recurrent venous and arterial thrombosis and pregnancy morbidity, paradoxically prolonging the aPTT in vitro while promoting clotting in vivo. Diagnosis requires a qualifying clinical event plus a laboratory antibody confirmed positive on two occasions at least 12 weeks apart, and thrombotic disease is treated with indefinite warfarin rather than a DOAC.

Infective endocarditis is microbial infection of the endocardium, usually a heart valve, producing vegetations that cause valve destruction, embolism, and systemic infection. Diagnosis uses the modified Duke criteria combining blood cultures and echocardiography, and treatment is prolonged targeted intravenous antibiotics with surgery for complications.