ABPN Vascular Neurology key terms

Anastomotic ring of arteries at the base of the brain formed by the anterior communicating, paired anterior cerebral, internal carotid, posterior communicating, and posterior cerebral arteries; it allows collateral flow between carotid and vertebrobasilar territories.

Small anastomotic connections between distal branches of the anterior, middle, and posterior cerebral arteries on the brain surface. They can supply retrograde flow to an ischemic territory when a proximal artery occludes, prolonging tissue survival.

The capacity of cerebral arterioles to dilate or constrict so that cerebral blood flow stays relatively constant across a range of mean arterial pressures, roughly 60 to 150 mmHg in healthy adults.

The pressure gradient driving blood through the brain, calculated as mean arterial pressure minus intracranial pressure. It guides blood pressure targets in patients with raised intracranial pressure or acute ischemic stroke.

Hypoperfused brain tissue that is dysfunctional but not yet infarcted, kept alive by collateral flow. Rapid reperfusion can salvage it; without reperfusion it evolves into core infarction over hours.

An ischemic lesion in the border zone between two major arterial territories, typically caused by severe hypoperfusion or proximal stenosis rather than a single embolic occlusion; often bilateral and between middle and anterior or posterior cerebral arteries.

A small deep brain infarct, usually under 15 to 20 mm, caused by occlusion of a single perforating artery and producing one of several classic lacunar syndromes without cortical signs.

Small perforating branches arising from the proximal middle cerebral artery that supply the basal ganglia and internal capsule; their occlusion causes deep infarcts and their rupture is a common cause of hypertensive hemorrhage.

A 15-item scored neurologic examination from 0 to 42 that quantifies stroke severity. It guides treatment decisions, predicts outcome, and is used to select patients for reperfusion and to monitor change.

A recombinant tissue plasminogen activator given intravenously within 4.5 hours of selected acute ischemic strokes to dissolve thrombus and restore perfusion; benefit falls and hemorrhage risk rises with delay.

Endovascular removal of a large-vessel occlusion with a stent retriever or aspiration catheter, typically within 24 hours of onset in selected patients with salvageable tissue, producing large improvements in functional outcome.

A 10-point CT scoring system subtracting one point for hypoattenuation in each of ten middle cerebral artery territory regions; lower scores indicate larger established infarction and predict hemorrhagic risk and poor outcome.

Comparison of a perfusion or diffusion abnormality with the infarct core to estimate salvageable tissue; mismatch profiles identify patients likely to benefit from reperfusion beyond standard time windows.

A pattern in which magnetic resonance diffusion restriction is present but fluid-attenuated inversion recovery signal is not, suggesting stroke onset within roughly 4.5 hours and used to select wake-up stroke patients for thrombolysis.

Large hemispheric infarction with progressive edema, mass effect, and herniation risk, usually from proximal middle cerebral artery occlusion; presents with decline in consciousness and requires urgent osmotic therapy or surgery.

A brief episode of focal neurologic dysfunction without infarction on imaging, caused by temporary ischemia; it signals high early stroke risk and warrants urgent evaluation and prevention.

Bleeding within brain parenchyma, most often from hypertensive small-vessel disease or cerebral amyloid angiopathy; hematoma expansion in the first hours worsens prognosis and is a target of hemostatic therapy.

Foci of contrast enhancement within an acute intracerebral hematoma on CT angiography, indicating active bleeding and predicting hematoma expansion and worse clinical outcome.

Bleeding into the subarachnoid space from a ruptured intracranial aneurysm, presenting with sudden severe headache; complications include rebleeding, vasospasm, hydrocephalus, and hyponatremia.

Delayed narrowing of large subarachnoid arteries after aneurysmal hemorrhage, typically days 3 to 14, reducing cerebral blood flow and contributing to delayed cerebral ischemia and poor outcome.

Neurologic deterioration or new infarction after subarachnoid hemorrhage attributed to vasospasm, microthrombosis, and cortical spreading depolarization; monitored with transcranial Doppler and treated with nimodipine and hemodynamic support.

Deposition of amyloid beta in cortical and leptomeningeal arteries, causing lobar microbleeds and hemorrhage in older adults; the Boston criteria support diagnosis and anticoagulation should be used cautiously.

A tangle of abnormal arteries and veins without an intervening capillary bed that can rupture causing intracerebral or subarachnoid hemorrhage, seizures, or steal-related deficits; treatment options include resection, embolization, and radiosurgery.

Thrombosis of the dural venous sinuses or cortical veins causing headache, papilledema, seizures, and venous infarction with hemorrhage; diagnosed by venous imaging and treated with anticoagulation even when hemorrhage is present.

A disorder of segmental cerebral artery constriction causing recurrent thunderclap headaches, often after vasoactive triggers; angiography shows a string-of-beads appearance and deficits usually resolve within weeks.

Progressive stenosis of the distal internal carotid and proximal cerebral arteries with compensatory fragile collateral vessels; causes ischemic and hemorrhagic stroke, chiefly in East Asian populations, and is treated with revascularization surgery.

A tear of the intimal layer of the carotid or vertebral artery, often after minor trauma, producing neck pain, Horner syndrome, and ischemic stroke from thromboembolism; treated with antiplatelet or anticoagulant therapy.

Non-inflammatory, non-atherosclerotic arterial disease producing irregular webs or a string-of-beads narrowing, most often in renal and cervical arteries; can cause dissection, stenosis, and stroke, especially in young women.

An abnormal connection between a radicular artery and a dural venous plexus that causes congestive myelopathy with progressive leg weakness, sensory loss, and sphincter dysfunction; treated by endovascular or surgical obliteration.

An autosomal dominant small-vessel disease from NOTCH3 mutations causing recurrent subcortical infarcts, cognitive decline, and migraine with aura, with characteristic white matter and anterior temporal pole involvement on MRI.

Surgical removal of atherosclerotic plaque from the carotid bifurcation to prevent stroke in patients with symptomatic severe stenosis; benefit is greatest when performed soon after the index event by an experienced surgeon.

Combined aspirin and a P2Y12 inhibitor such as clopidogrel, used short-term after minor stroke or high-risk transient ischemic attack and after carotid stenting; prolonged use raises bleeding risk.

A clinical score estimating stroke risk in atrial fibrillation from age, sex, heart failure, hypertension, diabetes, and prior stroke or vascular disease; it guides decisions about anticoagulation.

Narrowing of a major intracranial artery that caused a recent stroke or transient ischemic attack in its territory; high risk of recurrence and managed with intensive medical therapy rather than stenting in most patients.

A system that assigns ischemic stroke cause to one of five categories: large-artery atherosclerosis, cardioembolism, small-vessel occlusion, other determined cause, or undetermined; it standardizes etiologic workup and research.

Surgical removal of a large skull bone flap to relieve raised intracranial pressure from malignant middle cerebral artery infarction or large hemorrhage; improves survival and, in selected younger patients, functional outcome.

Ultrasound through skull windows measuring blood flow velocity in major intracranial arteries; used to detect vasospasm, stenosis, microembolic signals, and right-to-left shunts.

Rapid imaging that tracks contrast through the brain to estimate infarct core, ischemic tissue, and collateral flow, helping select patients for reperfusion therapy beyond conventional time windows.

Placement of a ventricular catheter or parenchymal probe to measure pressure inside the skull and guide treatment of cerebral edema, hemorrhage, and hydrocephalus in neurocritical care.