Ischemic Stroke

Overview

Ischemic stroke occurs when cerebral blood flow is interrupted, resulting in focal neurological dysfunction and potentially irreversible brain injury.

The underlying mechanism may involve large-artery atherosclerosis, cardioembolism, small-vessel disease, or other causes of arterial occlusion.

Acute ischemic stroke is a neurological emergency in which treatment decisions are highly time-sensitive.

Clinical Presentation

Presentation depends on the vascular territory involved. Patients may develop sudden weakness, sensory loss, facial asymmetry, speech disturbance, visual symptoms, ataxia, or neglect.

Recognition of the pattern of neurological deficit can help localize the affected region of the brain.

Sudden focal neurological deficit should be treated as stroke until an appropriate alternative diagnosis has been established.

Initial Assessment

Initial assessment focuses on the time of symptom onset or last known well time, neurological deficit, airway and breathing, circulation, blood glucose, and potential stroke mimics.

A structured neurological assessment helps quantify the severity of the deficit and provides a baseline for monitoring.

Establishing the exact time the patient was last known to be neurologically well is critical in acute stroke assessment.

Investigation

Brain imaging is required to distinguish ischemic stroke from intracranial hemorrhage and to guide acute treatment decisions.

Additional investigation may include vascular imaging, ECG, cardiac monitoring, blood glucose, full blood count, renal function, coagulation testing, and other studies directed toward identifying the underlying cause.

The first imaging priority in suspected acute stroke is to determine whether intracranial hemorrhage is present.

Acute Management

Management depends on the timing and severity of the stroke, the location and extent of vascular occlusion, imaging findings, and the patient's clinical condition.

Selected patients may be eligible for reperfusion therapy, including intravenous thrombolytic treatment and/or mechanical thrombectomy depending on the clinical and imaging criteria.

Supportive management includes attention to airway, oxygenation, glucose, temperature, blood pressure, swallowing, and prevention of complications.

Reperfusion eligibility should be assessed rapidly because the potential benefit of treatment decreases as cerebral ischemia progresses.

Clinical Pearls