Ischemic stroke

Small subcortical infarct, under 1.5 cm, from occlusion of a single penetrating artery, most often caused by hypertensive lipohyalinosis, producing one of five classic pure motor, pure sensory, ataxic hemiparesis, dysarthria-clumsy hand, or mixed sensorimotor syndromes without cortical signs, diagnosed by MRI and managed with the standard acute stroke pathway plus aggressive antiplatelet, statin, and blood pressure secondary prevention.

Cerebellar stroke, ischemic or hemorrhagic infarction of the cerebellum, presents with vertigo, truncal ataxia, dysarthria, and limb incoordination and is diagnosed with brain MRI when CT is falsely reassuring. Its defining danger is delayed swelling that compresses the brainstem and fourth ventricle, which is treated with emergent decompressive suboccipital craniectomy.

Basilar artery occlusion is a posterior circulation large-vessel stroke that threatens the brainstem, cerebellum, and thalami, presenting with rapidly progressive quadriparesis, cranial nerve palsies, and impaired consciousness, up to locked-in syndrome or coma. Diagnosis requires urgent CT angiography, and management is emergent reperfusion with IV alteplase followed by mechanical thrombectomy in eligible patients.

Spontaneous bleeding into brain parenchyma, most often from chronic hypertension affecting deep penetrating vessels or from cerebral amyloid angiopathy in lobar locations, diagnosed by noncontrast CT and managed with acute blood pressure lowering, reversal of anticoagulation, and surgical evacuation for select cerebellar or deteriorating hemorrhages.

Subarachnoid hemorrhage is sudden bleeding into the subarachnoid space, most often from a ruptured saccular (berry) aneurysm, presenting as the worst headache of a patient's life. Diagnosis is noncontrast head CT, then lumbar puncture if CT is negative, then catheter angiography to define the aneurysm; management is early aneurysm securement, blood pressure control, and nimodipine to reduce delayed cerebral ischemia from vasospasm.

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.

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.

A tear in the vertebral artery wall, spontaneous or from neck trauma or manipulation, that causes posterior circulation ischemia through thrombus formation or direct luminal narrowing. Presents with posterior neck or occipital headache plus brainstem or cerebellar signs, most classically a lateral medullary (Wallenberg) syndrome; diagnosed with MRI/MRA or CT angiography of the neck and treated with antithrombotic therapy.

Thrombosis of the dural venous sinuses or cortical veins that impairs cerebral venous drainage and CSF absorption, producing headache, papilledema, focal deficits, or seizures; MRI/MRV or CT venography establishes the diagnosis, and anticoagulation is first-line even when hemorrhagic venous infarction is present.