Does a patient with a National Institutes of Health Stroke Scale (NIHSS) score of 5 require thrombolysis?

From the Guidelines

A patient with an NIHSS score of 5 should be considered for thrombolysis if they meet other eligibility criteria, as the benefits of treatment are well established for adult patients with disabling stroke symptoms regardless of age and stroke severity 1.

Key Considerations

• Intravenous alteplase (tPA) at a dose of 0.9 mg/kg (maximum 90 mg) with 10% given as a bolus and the remainder infused over 60 minutes is the standard treatment, which should be administered within 4.5 hours of symptom onset for most patients 1.
• Before administering thrombolysis, it is crucial to confirm there are no contraindications such as recent surgery, active bleeding, use of anticoagulants with elevated INR, or evidence of intracranial hemorrhage on imaging.
• Blood pressure should be controlled to below 185/110 mmHg before and during treatment.
• An NIHSS score of 5 indicates a moderate stroke severity with potentially significant disability, and thrombolysis has been shown to improve outcomes across a wide range of stroke severities 1.

Post-Thrombolysis Care

• After thrombolysis, the patient should be monitored in an intensive care or stroke unit setting for at least 24 hours with frequent neurological assessments and blood pressure monitoring.
• The main elements of postthrombolysis care are listed in Table 7 of the guidelines 1, emphasizing the need for close monitoring and management to minimize risks and optimize outcomes.

Eligibility and Timing

• The eligibility criteria for IV alteplase have evolved over time, and a recent AHA statement provides a detailed discussion of this topic, including the recommendation to proceed with IV thrombolysis in an otherwise eligible adult patient with a disabling AIS when a patient cannot provide consent and a legally authorized representative is not immediately available 1.
• The benefit of IV alteplase is well established for adult patients with disabling stroke symptoms, and the treatment should be administered as soon as possible, given that earlier treatment leads to better outcomes 1.

From the Research

Thrombolysis in Patients with NIHSS Score 5

• The decision to administer thrombolysis to patients with a National Institutes of Health Stroke Scale (NIHSS) score of 5 depends on various factors, including the patient's overall health, medical history, and the severity of their stroke symptoms 2, 3.
• Studies have shown that patients with mild stroke and an NIHSS score of 3-5 may benefit from intravenous thrombolysis, with improved functional outcomes and no significant increase in symptomatic intracerebral hemorrhage (sICH) 2, 3.
• In contrast, patients with an NIHSS score of 0-2 may not benefit from thrombolysis and may even experience a higher risk of sICH 4, 3, 5.
• A study published in the Journal of Stroke and Cerebrovascular Diseases found that patients with an NIHSS score of 3-5 who received thrombolysis had a better functional outcome at discharge compared to those who did not receive thrombolysis 2.
• Another study published in Current Neurovascular Research found that intravenous thrombolysis was safe and effective in patients with an NIHSS score of 3-5, with significant improvement in 90-day functional prognosis 3.

Comparison of Thrombolysis and Antiplatelet Therapy

• A study published in The International Journal of Neuroscience compared the efficacy and safety of alteplase versus dual-antiplatelet therapy in acute minor stroke and found that patients treated with dual-antiplatelet therapy had a better functional outcome at 3 months compared to those who received alteplase therapy 5.
• The study also found that dual-antiplatelet therapy did not increase the risk of hemorrhage in acute minor ischemic stroke 5.
• Another study published in Stroke found that patients randomized in the PRISMS trial had comparable deficit and syndromic severity to patients not treated with alteplase in the MaRISS registry and lesser severity than patients treated with alteplase in MaRISS 6.

Safety and Efficacy of Thrombolysis

• The safety and efficacy of thrombolysis in patients with an NIHSS score of 5 depend on various factors, including the patient's overall health, medical history, and the severity of their stroke symptoms 2, 4, 3.
• Studies have shown that thrombolysis can be safe and effective in patients with mild stroke and an NIHSS score of 3-5, with improved functional outcomes and no significant increase in sICH 2, 3.
• However, thrombolysis may not be beneficial for patients with an NIHSS score of 0-2, and may even increase the risk of sICH 4, 3, 5.