Ischemic Stroke Predictive Risk Score
Check if you need help to estimate stroke severity (CNS)

Manual CNS/NHISS entry



Sex Male Female
Stroke Severity
Stroke Subtype

Risk Factors

Atrial fibrillation
Previous myocardial infarction
Current smoker

Comorbid Conditions

Renal disease on dialysis

Preadmission Disability


Glucose on Admission

≥7.5 mmol/L (>135 mg%)
Outcomes: Mortality

30 Day Mortality


1 Year Mortality

Functional Outcomes at Discharge

30 Day Death or Disability

Death or Disability

30 Day Death or Institutionalization

Death or Institutionalization
Death was captured up to 30-days post-discharge
Thrombolytic Therapy
Probability of Good Clinical Outcome (mRS 0-2)
tPA therapy
Complications of Intracranial Hemorrhage

Click here to download the original paper for the IScore

The early use of prognostic data using simple elements may help clinicians in making treatment decisions and in providing reliable information when counseling patients and their families.

The IScore (Ischemic Stroke Predictive Risk Score) is a validated tool that may assist clinicians to estimate the risk of death (at 30-day and at 1-year), disability (as defined by the modified Rankin scale >=3) and institutionalization, during the initial assessment in the Emergency department or early after hospital admission for patients with an acute ischemic stroke.

It consist in clinical parameters and chronic comorbid conditions: including age, sex, stroke severity and subtype, history of atrial fibrillation, coronary artery disease, cardiac cancer, kidney disease on dialysis, smoking, hyperglycemia on admission, and dependency prior to the stroke, all associated with 30-day and 1-year mortality. The score was validated in an internal and external cohorts including over 16,000 patients with an acute ischemic stroke.

IScore allows the input of stroke severity either using the CNS scale (as validated) or the NIHSS (commonly used in the initial assessment by stroke neurologists). Patients with decreased level of consciousness, i.e. coma, should be given a CNS = 0 or NIHSS >= 23.

The score assigned to each variable is shown in the right upper corner of this website. Just simple select the characteristics of your patient and you will have the estimated risk of death displayed right away.

View the NIH Stroke Scale.

Thrombolytic Therapy

Thrombolysis is the most accepted effective and proven treatment for an acute ischemic stroke. The decision of giving intravenous thrombolysis (tPA) may be challenging, especially in patients with higher prevalence comorbid conditions, pre-admission dependency, and dementia. Patients and families wonder about the likelihood of a good outcome, especially if the risk of developing hemorrhagic complications is high. Unfortunately, there are no tools that assist clinicians predict the response to tPA.

We recently developed and validated a risk score (iScore) that can be used to estimate the risk of death and disability after an acute ischemic stroke (Saposnik et al. Circulation 2011 and Stroke 2011). The iScore was designed to allow for broader utility at academic centers or small community hospitals with limited resources. It includes clinical variables easily obtained in the early hours of hospital presentation.

In the present study, we applied the iScore ( to over 12,000 patients with an acute ischemic stroke admitted to 11 stroke centers in Ontario. A cohort of patients with stroke treated at 154 general hospitals in Ontario was used to determine the consistency of our results.

Among patients with a low and medium iScore, tPA use was associated with reduction in death and disability. However, there was no such benefit in patients with a higher iScore. Moreover, the risk of neurological deterioration and intracerebral hemorrhage was significantly higher in this high risk group.

Patients with a high iScores may not have a clinically meaningful benefit from tPA (NNT 385; NS) while carrying a significantly higher risk of hemorrhagic complications (NNH 5-17; p<0.05)

Results were consistent in the validation cohort, as well as, when applying the iScore to data derived from the NINDS tPA randomized clinical trial (manuscript in preparation).

The risk, benefits, and quality of life after tPA in selected high risk groups has been under debate. Our study suggests that the iScore can be used to estimate the clinical response and risk of complications after thrombolytic therapy for ischemic stroke. These results may facilitate information to clinicians when discussing therapeutic options and prognosis with patients and their families.


NNH: number needed to harm
mRS 0-2: modified ranking scale 0-2 for a favorable outcome

Saposnik G, Fang J, Kapral M, Tu J, Mamdani M, Austin P, Johnston S, on behalf of the Investigators of the Registry of the Canadian Stroke Network (RCSN) and the Stroke Outcomes Research Canada (SORCan) Working Group. The iScore predicts effectiveness of thrombolytic therapy for acute ischemic stroke. Stroke February 2012.
Saposnik G, Kapral MK, Liu Y, O'Donnell M, Raptis R, Tu J, Mamdani M, Austin PC, on behalf of the Investigators of the Registry of the Canadian Stroke Network and the Stroke Outcome Research Canada (SORCan) Group. IScore: A Risk Score to Predict Death early after Hospitalization for an Acute Ischemic Stroke. Circulation February 2011.
Saposnik G, Raptis R, Kapral MK, Liu Y, Tu JV, Mamdani M, Austin PA, on behalf of the Investigators of the Registry of the Canadian Stroke Network and the Stroke Outcome Research Canada (SORCan) Working Group. The IScore Predicts Poor Functional Outcomes Early After Hospitalization for an Acute Ischemic Stroke. Stroke December 2011.
Nilanont Y, Komoltri C, Saposnik G, et al. The Canadian Neurological Scale and the NIHSS: development and validation of a simple conversion model. Cerebrovasc Dis. 2010;30(2):120-6.
The Canadian Neurological Scale: validation and reliability assessment. Côté R, Battista RN, Wolfson C, Boucher J, Adam J, Hachinski V. Neurology. 1989 May;39(5):638-43.

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