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96
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96
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The DRAGON Score is a validated clinical prediction tool designed to estimate the probability of favorable and unfavorable outcomes in patients with acute ischemic stroke treated with intravenous thrombolysis (tPA). Developed by Strbian and colleagues in 2012 using data from the Helsinki Stroke Thrombolysis Registry, the DRAGON Score combines six readily available clinical and imaging variables to predict both good outcome (modified Rankin Scale 0–2 at 3 months) and miserable outcome (mRS 5–6, representing severe disability or death).
The score incorporates the mnemonic DRAGON: Dense MCA sign or early infarct on CT, pre-stroke modified Rankin Scale, Age, Glucose at baseline, Onset-to-treatment time, and baseline NIHSS. Each variable is weighted to produce a total score ranging from 0 to 12. Higher scores indicate worse expected outcomes, while lower scores predict favorable recovery after thrombolytic therapy.
The DRAGON Score is particularly valuable in the acute stroke setting because all six variables are available before or at the time of tPA administration, enabling clinicians to set realistic expectations for patients and families and to guide shared decision-making about treatment intensity. It has been externally validated in multiple cohorts across different countries and healthcare systems, demonstrating good discrimination for both favorable and miserable outcomes.
This calculator computes the DRAGON Score and provides outcome probability estimates, supporting evidence-based prognostication and communication in the acute management of ischemic stroke patients receiving thrombolytic therapy.
The DRAGON Score sums points from six variables:
Total range: 0–12. Good outcome (mRS 0–2) probability decreases with higher scores, while miserable outcome (mRS 5–6) probability increases.
A DRAGON Score of 0–1 predicts excellent outcomes with approximately 96% probability of good outcome (mRS 0–2) and negligible risk of miserable outcome. Scores of 2–3 still predict favorable outcomes (78–88% good outcome probability). Scores of 4–5 indicate intermediate prognosis. Scores of 8–12 predict poor outcomes with less than 10% chance of good outcome and over 55% risk of miserable outcome (mRS 5–6).
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Results
DRAGON 1 — young, independent, treated early with moderate NIHSS. 96% chance of good outcome.
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Results
DRAGON 11 — elderly, dependent, severe stroke, hyperglycemia, late treatment. Very poor expected outcome.
DRAGON is a mnemonic for the six scoring variables: Dense MCA sign/early infarct on CT, pre-stroke Rankin scale, Age, Glucose at baseline, Onset-to-treatment time, and baseline NIHSS.
The DRAGON Score is calculated at the time of IV thrombolysis administration, as all six variables are available at that point. It provides immediate prognostic information.
Good outcome is defined as modified Rankin Scale (mRS) 0–2 at 3 months, meaning functional independence with no disability or only slight disability not limiting daily activities.
Miserable outcome is defined as mRS 5–6 at 3 months, meaning severe disability (bedridden, incontinent, requiring constant nursing) or death.
Not necessarily. The DRAGON Score predicts outcomes but does not replace clinical judgment about treatment eligibility. Even patients with high scores may benefit from treatment.
Hyperglycemia (>8 mmol/L or 144 mg/dL) at the time of stroke is associated with worse outcomes, likely due to increased oxidative stress, blood-brain barrier disruption, and larger infarct volumes.
The hyperdense MCA (middle cerebral artery) sign on non-contrast CT indicates a clot in the MCA, suggesting a large vessel occlusion. It is associated with more severe strokes and poorer outcomes with IV tPA alone.
Yes. The DRAGON Score has been externally validated in multiple international cohorts, demonstrating consistent and reliable prediction of outcomes after IV thrombolysis for ischemic stroke.
The DRAGON Score was developed for IV tPA-treated patients specifically. While some variables overlap with thrombectomy outcome predictors, specific thrombectomy scoring tools may be more appropriate.
The maximum score is 12, representing the worst combination of all factors: both CT findings, pre-existing disability, age ≥80, hyperglycemia, late treatment, and severe baseline NIHSS.
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