NeuroBrief Episode 1

Acute Ischemic Stroke

Welcome to our first episode of NeuroBrief, where we provide concise, high-yield neurology content. Episode 1 focuses on acute ischemic stroke, a critical emergency that requires prompt recognition and management. With ischemic strokes comprising 87% of all strokes, fine-tuning our approach to diagnosis and treatment remains crucial for optimizing patient outcomes.

Clinical Presentation

Acute ischemic stroke typically manifests with sudden-onset neurological deficits. While the classic presentation includes unilateral weakness, facial droop, and aphasia, we must remain vigilant for more subtle presentations. Time remains a critical factor, and rapid differentiation from TIA, intracerebral hemorrhage, and stroke mimics like migraine with aura or hypoglycemia is essential.

Diagnostic Approach

A rapid, accurate diagnostic workup is key. Start with a non-contrast CT to exclude hemorrhage. An MRI with diffusion-weighted imaging (DWI) remains the gold standard for detecting early ischemic changes.

The NIH stroke scale should be performed on every stroke patient—not just as a severity metric but as a guide for treatment decisions. Even in cases with a low NIHSS, patients presenting with disabling symptoms like aphasia or hemiparesis should be considered for thrombolysis.

In the inpatient setting, a comprehensive workup is crucial. This includes:

• MRI brain without contrast
• A 2D echocardiogram with bubble study
• A1C
• LDL targets below 70

Continuous telemetry monitoring is essential to rule out arrhythmias like atrial fibrillation. Evaluation by speech, PT, and OT is imperative for a holistic recovery plan.

Determining the stroke etiology is a critical step, guided by the TOAST criteria, which classify strokes into five categories:

1. Large-artery atherosclerosis: Stroke due to significant stenosis or occlusion of a major artery.
2. Cardioembolism: Stroke due to emboli from the heart, often associated with conditions like atrial fibrillation.
3. Small vessel occlusion (lacunar stroke): Stroke resulting from occlusion of small, penetrating arteries, typically seen in hypertension or diabetes.
4. Stroke of other determined etiology: Less common causes such as vasculitis, hypercoagulable states, or arterial dissection.
5. Stroke of undetermined etiology: When no definitive cause is identified despite extensive evaluation.

For cryptogenic strokes, it is essential to rule out occult atrial fibrillation and other paroxysmal arrhythmias, often necessitating prolonged monitoring with a loop recorder or an event monitor before discharge. Throughout this diagnostic process, remain vigilant for common pitfalls, such as stroke mimics or missing small but clinically significant infarcts.