Chapter 141. Stroke, Transient Ischemic Attack, and Subarachnoid Hemorrhage

Ischemic

Thrombotic

Narrowing of a damaged vascular lumen by an in situ process, usually clot formation

Atherosclerosis

Vasculitis

Arterial dissection

Polycythemia

Hypercoagulable state

Infection (human immunodeficiency virus infection, syphilis, trichinosis, tuberculosis, aspergillosis)

Symptoms often have gradual onset and may wax and wane.

Common cause of transient ischemic attack.

Embolic

Obstruction of a normal vascular lumen by intravascular material from a remote source

Valvular vegetations

Mural thrombi

Paradoxical emboli

Cardiac tumors (myxomas)

Arterial-arterial emboli from proximal source

Fat emboli

Particulate emboli (intravenous drug use)

Septic emboli

Typically sudden in onset.

Account for 20% of ischemic strokes.

Hypoperfusion

Low–blood flow state leading to hypoperfusion of the brain

Cardiac failure resulting in systemic hypotension

Diffuse injury pattern in watershed regions.

Symptoms may wax and wane with hemodynamic factors.

Hemorrhagic

Intracerebral

Intraparenchymal hemorrhage from previously weakened arterioles

Hypertension

Amyloidosis

Iatrogenic anticoagulation

Vascular malformations

Cocaine use

Intracranial pressure rise causes local neuronal damage.

Secondary vasoconstriction mediated by blood breakdown products or neuronal mechanisms (diaschisis) can cause remote perfusion changes.

Risks include advanced age, history of stroke, tobacco or alcohol use.

More common in Asians and blacks.

Nontraumatic subarachnoid

Hemorrhage into subarachnoid space

Berry aneurysm rupture

Vascular malformation rupture

May be preceded by a sentinel headache (“warning leak”).

Traditional symptoms

Sudden numbness or weakness of face, arm, or leg—especially unilateral

Sudden confusion or aphasia

Sudden memory deficit or spatial orientation or perception difficulties

Sudden visual deficit or diplopia

Sudden dizziness, gait disturbance, or ataxia

Sudden severe headache with no known cause

Nontraditional symptoms

Loss of consciousness or syncope

Shortness of breath

Sudden pain in the face, chest, arms, or legs

Seizure

Falls or accidents

Sudden hiccups

Sudden nausea

Sudden fatigue

Sudden palpitations

Altered mental status