Management of Mild Stroke (NIHSS 2) Without Vessel Obstruction
For a patient with NIHSS 2 and no vessel obstruction on CTA, you should initiate aspirin therapy (50-100 mg daily) and avoid IV thrombolysis, focusing instead on secondary stroke prevention measures and close monitoring for early neurological deterioration. 1, 2
Rationale Against Thrombolysis in This Scenario
The absence of large vessel occlusion on CTA is a critical factor that argues against endovascular thrombectomy, as all major trials establishing thrombectomy benefit (MR CLEAN, ESCAPE, SWIFT PRIME) specifically enrolled patients with confirmed proximal intracranial occlusions. 1, 3
For the NIHSS score of 2 specifically:
NIHSS 0-2 represents the lowest severity category where thrombolysis shows questionable benefit and potential harm. Real-world registry data demonstrates that patients with NIHSS 0-1 who received IV thrombolysis had increased early neurological deterioration (adjusted OR 8.84), symptomatic intracranial hemorrhage (adjusted OR 9.32), and paradoxically lower rates of excellent outcome at 3 months (adjusted OR 0.67). 4
The American Heart Association guidelines specifically note that approximately one-third of patients with mild or rapidly improving symptoms who are not treated with thrombolysis still have poor outcomes, but this observation does not translate into proven benefit from treatment in the NIHSS 0-2 range. 1
Patients with NIHSS 3-5 show different risk-benefit profiles than NIHSS 0-2, with some evidence supporting thrombolysis in the 3-5 range when deficits are disabling, but this threshold distinction is clinically important. 5, 6
Recommended Management Algorithm
Immediate Actions (First 24-48 Hours)
Initiate aspirin 50-100 mg daily as the American College of Chest Physicians recommends early aspirin therapy for acute ischemic stroke patients not receiving thrombolysis (Grade 1A recommendation). 2
Admit to a specialized stroke unit with coordinated interdisciplinary care, as stroke patients should be treated on geographically defined stroke rehabilitation units even with minor deficits. 1
Monitor closely for early neurological deterioration, which occurs in a subset of mild stroke patients and may indicate evolving infarction or hemorrhagic transformation. 4
Initiate DVT prophylaxis with low-dose subcutaneous heparin or LMWH for patients with restricted mobility (Grade 1A recommendation). 2
Diagnostic Workup for Secondary Prevention
Complete vascular imaging if not already done: The absence of large vessel occlusion on your CTA is reassuring, but ensure complete evaluation of extracranial carotid and vertebral arteries. 1
Cardiac evaluation including prolonged cardiac monitoring (minimum 24 hours, ideally 30 days) to detect paroxysmal atrial fibrillation, as this fundamentally changes anticoagulation strategy. 1
Echocardiography to evaluate for cardioembolic sources including patent foramen ovale, atrial septal abnormalities, and left ventricular thrombus. 1
Laboratory assessment including lipid panel, hemoglobin A1c, and consideration of hypercoagulable workup in younger patients or those with cryptogenic stroke. 1
Long-Term Secondary Prevention Strategy
The specific antiplatelet regimen depends on stroke mechanism:
For noncardioembolic stroke (atherothrombotic, lacunar, or cryptogenic), the American College of Chest Physicians recommends combination aspirin/extended-release dipyridamole (25 mg/200 mg twice daily) over aspirin alone (Grade 1A), or clopidogrel 75 mg daily over aspirin (Grade 2B). 2
Avoid long-term combination aspirin plus clopidogrel (Grade 1B recommendation against this combination). 2
If atrial fibrillation is detected, switch to oral anticoagulation with target INR 2.5 (range 2.0-3.0) or a direct oral anticoagulant. 2, 1
Aggressive blood pressure control with target <140/90 mmHg (or <130/80 mmHg if tolerated) for long-term secondary prevention. 1
Statin therapy regardless of baseline LDL, as prior statin therapy is an independent predictor of excellent outcomes (adjusted OR 3.46). 6
Critical Pitfalls to Avoid
Do not assume that low NIHSS guarantees good outcome. Approximately 15% of patients with baseline NIHSS ≤4 have poor outcomes at 3 months, and one-third of untreated mild stroke patients experience unfavorable final outcomes. 1, 7
Do not withhold workup intensity based on mild presentation. The absence of large vessel occlusion suggests small vessel disease, lacunar infarction, or cardioembolic mechanism with spontaneous recanalization—all require thorough evaluation. 1
Be particularly vigilant if this is a posterior circulation stroke, as posterior circulation strokes often present with deceptively low NIHSS scores but carry significant risk of poor outcomes. The optimal NIHSS cutoff for outcome prediction is 4 points lower in posterior circulation (cutoff of 4) compared to anterior circulation (cutoff of 8). 7
Recognize that "non-disabling" is a clinical judgment, not purely NIHSS-based. Certain deficits like isolated aphasia, hemianopia, or gait disturbance may have NIHSS scores of only 2 but are potentially disabling and warrant more aggressive consideration of interventions. 1
Rehabilitation and Follow-Up
Early mobilization within 48 hours unless contraindicated, but avoid intensive out-of-bed activities within the first 24 hours. 1
Initial assessment by rehabilitation professionals as soon as possible after admission, even for mild strokes. 1
Patient and family education regarding stroke warning signs, risk factor modification, and medication adherence. 1
Follow-up imaging is not routinely required if the patient remains stable, but consider repeat vascular imaging if symptoms progress or if initial mechanism remains unclear. 1