Low NIHSS Stroke: Thrombolysis Turns on Disabling Deficits

A 71-year-old retiree who lives alone arrives 80 minutes after last known well. The neighbor who called 911 says he could not get from his recliner to the door. Your exam finds right leg drift that hits the bed and nothing else, so the NIHSS is 2. The noncontrast CT shows no hemorrhage, and the nurse asks whether this is a "mild stroke, no lytic" patient.

Bottom line: inside 4.5 hours, the thrombolysis decision for an NIHSS 0 to 5 patient turns on whether the deficit is disabling, not on the total score. Treat eligible disabling deficits promptly; give dual antiplatelet therapy for non-disabling deficits.

How the guideline defines disabling

The 2026 AHA/ASA guideline states that the NIHSS score alone does not suffice, and uses this exact case as its example: leg weakness that prevents walking can score 2 and is still disabling [1]. Its Table 4 asks one question for patients with NIHSS 0 to 5. If the deficit persists, could the patient still perform basic activities of daily living or return to work? The guideline uses the BATHE mnemonic: bathing and dressing, ambulating, toileting, hygiene, eating. It directs you to test walking and swallowing and to make the call with the patient and available family [1].

The table lists deficits typically considered clearly disabling: complete hemianopia (2 or more on the vision item), severe aphasia (2 or more on best language), severe extinction to more than one modality (2 or more on that item), and any weakness that limits sustained effort against gravity (2 or more on a motor item) [1]. Deficits that often do not meet that bar include isolated mild aphasia with meaningful communication, isolated facial droop, mild cortical hand weakness, hemisensory loss, and mild hemiataxia with preserved walking [1]. The guideline calls the table a guide that still requires individual judgment. A hand deficit means something different to a welder than to a retiree who no longer works.

Treatment criteria for disabling deficits

For an adult with a disabling deficit inside 4.5 hours of onset or last known well, the guideline recommends tenecteplase 0.25 mg/kg (maximum 25 mg) as a single push or alteplase 0.9 mg/kg (maximum 90 mg), 10% as a bolus and the rest over 60 minutes [1]. Noncontrast CT is sufficient imaging for most patients. The guideline recommends against delaying treatment for CTA or perfusion imaging [1]. Do not wait for platelet or coagulation results unless history suggests coagulopathy [1]. Correct severe hypoglycemia (under 50 mg/dL) or hyperglycemia (over 400 mg/dL) first, then reexamine; deficits that remain disabling stay eligible [1]. Extensive early hypodensity should send you back to the onset history [1]. The full contraindication review in the guideline still applies. When an aphasic or confused patient cannot consent and no representative is available, the guideline supports treating an otherwise eligible patient with disabling deficits [1].

What the trials showed for non-disabling deficits

PRISMS was a double-blind, double-placebo US trial at 53 stroke networks. It enrolled 313 patients with NIHSS 0 to 5 whose deficits were judged not clearly disabling, treatable within 3 hours [2]. Investigators defined clearly disabling as a deficit that would prevent basic activities of daily living or return to work, and patients had to walk unassisted [2]. Alteplase 0.9 mg/kg was compared with aspirin 325 mg. At 90 days, modified Rankin 0 to 1 occurred in 78.2% with alteplase and 81.5% with aspirin (adjusted risk difference -1.1%, 95% CI -9.4% to 7.3%). Symptomatic intracranial hemorrhage occurred in 3.2% versus 0% [2]. The trial stopped early after enrolling 313 of a planned 948, and the authors state this precludes definitive conclusions [2].

ARAMIS was an open-label, blinded-endpoint noninferiority trial at 38 hospitals in China with 760 patients [3]. Its definition was stricter: NIHSS 5 or less, no more than 1 point on any key single item (vision, language, neglect, single-limb weakness), and 0 on consciousness, plus a judgment from patient and family that the deficit would not affect daily activities or work [3]. Patients treated within 4.5 hours received clopidogrel 300 mg plus aspirin 100 mg, then both daily for 12 days, or alteplase 0.9 mg/kg. Excellent outcome (modified Rankin 0 to 1) occurred in 93.8% with dual antiplatelet therapy and 91.4% with alteplase, meeting noninferiority [3]. Symptomatic hemorrhage was 0.3% versus 0.9%. Early neurologic deterioration was 4.6% versus 9.1% [3]. No subgroup showed significant heterogeneity, although in patients with NIHSS 4 to 5 the point estimate favored alteplase [3]. Patients with possible cardioembolism were excluded, and the authors call for confirmation outside China [3].

TEMPO-2 and the disabling subgroup

TEMPO-2 was an open-label, blinded-outcome trial at 48 hospitals in ten countries [4]. It enrolled 886 patients with NIHSS 0 to 5 and a proven intracranial occlusion or focal perfusion deficit within 12 hours, and compared tenecteplase 0.25 mg/kg with nonthrombolytic care. Return to baseline function at 90 days occurred in 72% with tenecteplase and 75% with control (risk ratio 0.96, 95% CI 0.88 to 1.04). Deaths were 5% versus 1% (adjusted hazard ratio 3.8), and symptomatic hemorrhage was 2% versus less than 1% [4]. The trial stopped for futility, and the authors concluded these patients should not be routinely treated with thrombolysis [4].

A 2025 secondary analysis classified 100 of 884 patients as disabling using the TREAT Task Force definition [5]. In that disabling subgroup, return to baseline occurred in 54.7% with tenecteplase and 68.1% with control (adjusted risk ratio 0.81, 95% CI 0.60 to 1.10). Tenecteplase showed no benefit, and the point estimate favored control. The non-disabling subgroup was also neutral (73.9% versus 75.6%). The disabling group arrived later, with a median onset-to-treatment time of 411 minutes, well outside the 4.5-hour window [5]. The authors conclude thrombolysis in minor disabling stroke needs reevaluation [5]. The guideline notes that TEMPO-2 did not define mild deficits beyond local clinical judgment [1]. This subgroup is the open question in this topic. It is small, mostly late, and limited to patients with occlusion, so it does not overturn the 4.5-hour recommendation.

Dual antiplatelet criteria

CHANCE randomized 5,170 patients at 114 Chinese centers with NIHSS 3 or less or high-risk TIA (ABCD2 4 or more) within 24 hours [6]. Clopidogrel 300 mg then 75 mg daily plus aspirin 75 mg for 21 days reduced 90-day stroke from 11.7% to 8.2% (hazard ratio 0.68), with moderate or severe hemorrhage at 0.3% in both groups [6]. POINT randomized 4,881 patients at 269 international sites within 12 hours using a 600 mg clopidogrel load and 90 days of therapy. Major ischemic events fell from 6.5% to 5.0%, and major hemorrhage rose from 0.4% to 0.9% [7]. The guideline cites a POINT analysis placing the benefit within the first 21 days and supports limiting therapy to 21 days, followed by a single agent [1]. Both trials enrolled noncardioembolic events [1].

Key Takeaways

• An isolated leg deficit that prevents walking can score NIHSS 2 and is disabling; test gait and swallowing and document the BATHE answer before you call it mild [1].
• Disabling and inside 4.5 hours: tenecteplase 0.25 mg/kg (maximum 25 mg) or alteplase 0.9 mg/kg (maximum 90 mg) after noncontrast CT, without waiting for CTA, perfusion, or routine labs [1].
• Non-disabling, NIHSS 3 or less, noncardioembolic, within 24 hours: clopidogrel 300 mg or 600 mg load plus aspirin, then 21 days of both before a single agent [1,6,7].
• In TEMPO-2, minor stroke with occlusion did worse with tenecteplase (deaths 5% versus 1%), and its 100-patient disabling subgroup showed no benefit [4,5].

FAQ

Does an NIHSS of 0 to 5 exclude a patient from thrombolysis?

No. The 2026 AHA/ASA guideline bases the decision on whether the deficit is disabling. An eligible patient with a disabling deficit inside 4.5 hours should be treated promptly [1].

Which low-NIHSS deficits are typically disabling?

Complete hemianopia, severe aphasia, severe extinction, and any weakness that cannot sustain effort against gravity, each scoring 2 or more on its NIHSS item [1]. A deficit that prevents walking or swallowing also qualifies [1].

What dual antiplatelet regimen fits a non-disabling minor stroke?

For noncardioembolic stroke with NIHSS 3 or less within 24 hours, clopidogrel 300 mg or 600 mg load plus aspirin, then both daily for 21 days before a single agent [1,6,7]. ARAMIS used clopidogrel 300 mg plus aspirin 100 mg within 4.5 hours [3].

Dr. Chet's Take

I have worked as an ED attending for more than 25 years, and I direct TelEmergency for rural Mississippi emergency departments. This piece gets the central call right. Disability is a clinical judgment you have to make and write down, and the NIHSS total cannot make it for you. The core argument holds because the guideline built Table 4 for exactly this patient. What I would add is about who makes the judgment. In a rural department, the stroke neurologist is often on a screen. The camera shows the face and arms well. It rarely shows the patient trying to stand, swallow water, or button a shirt. Someone in the room has to do those tests on purpose and report them in plain words. If nobody tells the consultant that the patient cannot walk, the consultant is deciding on a score of 2.

That being said, the TEMPO-2 disabling subgroup deserves more respect than a footnote. The honest answer is that I do not know whether a patient with a small, disabling deficit and an occlusion does better with a lytic. The data we have point the wrong direction. My position stays with treatment inside 4.5 hours, because that is where the guideline stands and the subgroup was never built to change it. Where I push back is on how teams use the CTA. A low-score patient with a visible occlusion is a thrombectomy conversation, and the strongest thrombectomy recommendations were written for higher scores. That decision belongs with the interventional team, and the call should go out while you are still deciding on the lytic.

If you are the attending, make disability an explicit line in your note before the lytic decision. Write what the patient cannot do, how you tested it, and who confirmed baseline function. Then decide, and name the branch you chose. If the consult is remote, stand the patient up on camera or tell the consultant in one sentence what happened when you tried. Ask your stroke committee to add a gait and swallow check to the code stroke flow sheet so nobody skips it at 3 a.m. Teach your nurses the BATHE question too, because they often hear the answer first, from the family in the hallway. When the answer is unclear, say so in the chart and call it disabling or not anyway. A documented disability judgment protects the patient you treat and the patient you do not.

— Chester Shermer, MD, FACEP | Emergency Medicine, 25+ Years Clinical Experience | State Surgeon

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References

1. Prabhakaran S, Gonzalez NR, Zachrison KS, et al. 2026 Guideline for the Early Management of Patients With Acute Ischemic Stroke: A Guideline From the American Heart Association/American Stroke Association. Stroke. 2026;57(8):e316-e436. PubMed
2. Khatri P, Kleindorfer DO, Devlin T, et al. Effect of Alteplase vs Aspirin on Functional Outcome for Patients With Acute Ischemic Stroke and Minor Nondisabling Neurologic Deficits: The PRISMS Randomized Clinical Trial. JAMA. 2018;320(2):156-166. PubMed
3. Chen HS, Cui Y, Zhou ZH, et al. Dual Antiplatelet Therapy vs Alteplase for Patients With Minor Nondisabling Acute Ischemic Stroke: The ARAMIS Randomized Clinical Trial. JAMA. 2023;329(24):2135-2144. PubMed
4. Coutts SB, Ankolekar S, Appireddy R, et al. Tenecteplase versus standard of care for minor ischaemic stroke with proven occlusion (TEMPO-2): a randomised, open label, phase 3 superiority trial. Lancet. 2024;403(10444):2597-2605. PubMed
5. Zhang Y, Buck BH, Barber PA, et al. Thrombolysis With Tenecteplase for Minor Disabling Stroke: Secondary Analysis of the TEMPO-2 Randomized Clinical Trial. JAMA Neurol. 2025;82(12):1243-1250. PubMed
6. Wang Y, Wang Y, Zhao X, et al. Clopidogrel with aspirin in acute minor stroke or transient ischemic attack. N Engl J Med. 2013;369(1):11-19. PubMed
7. Johnston SC, Easton JD, Farrant M, et al. Clopidogrel and Aspirin in Acute Ischemic Stroke and High-Risk TIA. N Engl J Med. 2018;379(3):215-225. PubMed

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