What is the difference in presentation and management between an ischemic (infarct) stroke and a hemorrhagic stroke?

Distinguishing Ischemic Infarct from Hemorrhagic Stroke

Immediate Imaging is Mandatory—Clinical Features Alone Are Inadequate

Brain imaging is absolutely required to differentiate ischemic stroke from intracerebral hemorrhage, as clinical features overlap substantially and have insufficient accuracy to guide treatment decisions. 1 Non-contrast CT head must be completed within 30 minutes of hospital arrival, with interpretation within an additional 20 minutes, to enable time-sensitive treatment decisions. 2

Clinical Presentation: Overlapping but Suggestive Features

While imaging remains the gold standard, certain clinical features increase the probability of hemorrhagic stroke:

Features More Common in Hemorrhagic Stroke:

• Coma or markedly decreased level of consciousness on arrival 1, 3
• Severe headache at onset 1, 3
• Vomiting 1, 2
• Systolic blood pressure >220 mmHg 1, 2
• Seizures at onset 3
• Dilated pupils 3
• Agitation 3
• Eye gaze impairment 3
• Current warfarin therapy 1
• Blood glucose >170 mg/dL in non-diabetic patients 1

Features More Common in Ischemic Stroke:

• Gradual progressive headache (rather than acute severe headache) 3
• Absence of the hemorrhagic features listed above decreases hemorrhage odds by approximately one-third 1

However, the presence or absence of these features has inadequate sensitivity and specificity—diagnostic errors occur frequently when relying on clinical assessment alone. 1 In one series, 13% of patients initially diagnosed with stroke had alternative diagnoses including seizures, hypoglycemia, brain tumors, or subdural hematoma. 1

Imaging Protocol: The Definitive Diagnostic Step

CT Scanning (First-Line Modality):

• CT remains the most practical and widely available imaging test for acute stroke evaluation 1
• CT is the gold standard for detecting acute hemorrhage 2
• Complete CT within 25 minutes of emergency department arrival, with interpretation within 45 minutes total (door-to-interpretation time) 1
• CT immediately distinguishes hemorrhage from infarction and excludes stroke mimics 1, 2

MRI as Alternative:

• MRI with diffusion-weighted imaging (DWI) and gradient echo or T2-susceptibility sequences is as sensitive as CT for acute blood detection* 2
• MRI has higher sensitivity (88-100%) and specificity (95-100%) for detecting acute ischemia, even at very early time points 1
• MRI can detect small cortical, subcortical, brainstem, and cerebellar lesions poorly visualized on CT 1
• However, logistical issues including equipment availability, time constraints, and expertise in interpretation limit MRI use in the acute setting 1, 2
• Do not delay treatment with intravenous rtPA while obtaining MRI if CT has already excluded hemorrhage 1

Critical Management Divergence Based on Imaging Results

If Ischemic Infarct Confirmed:

Administer IV rtPA (0.9 mg/kg, maximum 90 mg) if patient presents within 3 hours of symptom onset and has no contraindications. 2 This represents the single most important time-sensitive intervention for ischemic stroke.

• Blood pressure must be <185/110 mmHg before thrombolysis, then maintained <180/105 mmHg for 24 hours post-treatment 2
• Start aspirin 160-325 mg within 48 hours of ischemic stroke onset, but delay until 24 hours after thrombolysis if rtPA was administered 2
• Avoid aggressive blood pressure lowering unless >220/120 mmHg—permissive hypertension may maximize cerebral perfusion to penumbral tissue 2
• Monitor intensively for hemorrhagic transformation: symptomatic intracranial hemorrhage occurs in 6.4% of rtPA-treated patients 1

If Intracerebral Hemorrhage Confirmed:

Immediately discontinue and reverse any anticoagulation. 2, 4 This is the most critical initial step.

• For spontaneous ICH with systolic BP 150-220 mmHg presenting within 6 hours: acutely reduce systolic BP to target of 140 mmHg (avoiding SBP <110 mmHg) 2, 4, 5
• Never administer aspirin, heparin, rtPA, or any antithrombotic therapy 2
• For warfarin-associated hemorrhage with elevated INR: administer prothrombin complex concentrate plus intravenous vitamin K 4, 5
• Obtain prompt neurosurgical consultation 4, 5
• Consider external ventricular drainage if hydrocephalus with decreased consciousness develops 2, 5
• Patients with cerebellar hemorrhage who are deteriorating neurologically or have brainstem compression should undergo surgical removal as soon as possible 4, 5

Essential Baseline Studies (Do Not Delay Imaging)

Obtain these immediately but do not delay imaging or thrombolytic therapy while awaiting results unless clinical suspicion of bleeding abnormality, thrombocytopenia, or known anticoagulant use exists: 2

• Blood glucose (hypoglycemia mimics stroke) 1, 2
• Complete blood count with platelet count 1, 2
• Prothrombin time/INR and activated partial thromboplastin time 1, 2
• Serum electrolytes and renal function 1, 2
• 12-lead ECG 2

Time-Critical Workflow

The entire evaluation from door to imaging interpretation to treatment decision must occur within 60 minutes for ischemic stroke patients eligible for thrombolysis. 2 The specific timeline:

1. Triage as highest priority upon arrival 2
2. Complete non-contrast CT within 30 minutes 2
3. Obtain NIHSS score and verify exact time of symptom onset or last known well 2
4. Achieve door-to-needle time ≤30 minutes if thrombolysis indicated 2

Common Pitfalls to Avoid

• Never rely on clinical features alone to distinguish hemorrhage from infarction—even experienced clinicians make diagnostic errors 1
• Do not assume gradual onset excludes hemorrhage—approximately 30% of stroke patients deteriorate in the first 24 hours regardless of type 1
• Recognize that hemorrhagic transformation can occur naturally in ischemic stroke (petechial hemorrhages found in almost all cerebral infarcts on pathology), and is increased 8-fold with rtPA when early edema or mass effect is present on CT 1, 6
• For patients awakening with stroke symptoms, time of onset is the time last known to be symptom-free before sleep—not the time of awakening 1
• Hematoma expansion occurs in 30-40% of hemorrhagic stroke patients and predicts poor outcome—early blood pressure control is critical 5