Giles MF et al., Stroke 2010
In 20 cohorts with 9,808 patients and 456 strokes within 7 days, the pooled area under the curve was 0.72 for both ABCD and ABCD²; most of the variation between studies came from study method and setting (75% of it).
- Neurology
- Emergency medicine
- Stroke
ABCD² Score Calculator for TIA
Scores the early stroke risk after a transient ischemic attack from five bedside features.
Result
Answer the five questions to see the score.
Sources
3 studies
3
studies
1,341
citations
535
PubMed papers
Evidence
The validation study, the meta-analyses of its accuracy, and a modern cohort of rapidly treated patients.
Known limitations
- Only for symptoms that have fully resolved and are thought to be a TIA.
- Poor at separating low- from high-risk patients; misses atrial fibrillation and carotid stenosis.
- The 2-day risks come from cohorts treated before modern rapid-access TIA care; risks are lower today.
- Does not tell a TIA from its mimics.
Key papers
Wardlaw JM et al., Neurology 2015
In 29 studies of 13,766 patients, a score of 4 or more was 86.7% sensitive but 35.4% specific for stroke within 7 days; 20% of patients scoring below 4 had a carotid stenosis of more than 50% or atrial fibrillation. The authors conclude the score does not reliably separate low- and high-risk patients.
Neurology: Journal Metrics Score 1.1, Q3 · cited 161 times
PubMed · Free full text · DOI
Amarenco P et al., N Engl J Med 2016
In 4,789 patients with TIA or minor stroke seen quickly by stroke specialists, stroke risk was 1.5% at 2 days and 5.1% at 1 year. Multiple infarcts on imaging, large-artery atherosclerosis and an ABCD² of 6 or 7 each more than doubled the 1-year risk.
N Engl J Med: Journal Metrics Score 29.8, Q1 · cited 619 times
The original paper has been cited 1,341 times, and 535 PubMed articles mention the ABCD² score in their title or abstract. Citation counts from OpenAlex and article counts from PubMed, retrieved November 13, 2026. Journal Metrics Scores and quartiles are from this site’s current release; follow the journal name for details.
After the result
Any suspected TIA · Symptoms still present · Before scoring
- Any suspected TIA
- Symptoms still present
- Before scoring
Specialist assessment without delay. Treat as acute stroke. Check it was a TIA.
Next steps
Any suspected TIA
- Arrange specialist assessment as soon as possible, within 24 hours of symptom onset, whatever the score.
- Brain imaging (preferably MRI), carotid imaging and an ECG look for the causes that change treatment: a new infarct, carotid stenosis and atrial fibrillation.
- Start antiplatelet treatment straight away unless there is a contraindication, following your local pathway (NICE advises aspirin immediately for a suspected TIA). Image the brain first if the patient takes an anticoagulant, has a bleeding tendency or still has symptoms.
Symptoms still present
- If the deficit has not fully resolved, call the stroke team; reperfusion treatment may be possible.
Before scoring
- Check the glucose and consider mimics such as migraine aura, seizure, syncope and functional symptoms.
- In a patient on anticoagulants or after head injury, image first: a bleed can cause transient symptoms.
Avoid common errors
5 common errors to avoid
- 1A low score is not low risk
- 2Mimics score points
and 3 more
When the score misleads
1A low score is not low risk
About 1 in 5 patients scoring below 4 had atrial fibrillation or a carotid stenosis of more than 50%, which need urgent treatment.
2Mimics score points
Over a third of TIA mimics scored 4 or more in a meta-analysis; the score does not decide whether the event was a TIA.
3Blood pressure timing
Use the first blood pressure after the event. Pain and anxiety at that point can raise it.
4Duration is often uncertain
Patients and witnesses may not know how long symptoms lasted; record how the duration was judged.
5Imaging adds to the score
In a 2016 cohort, multiple acute infarcts on imaging and large-artery atherosclerosis each more than doubled the 1-year stroke risk, independently of the score. Scores that add brain and carotid imaging (ABCD²-I, ABCD³-I) discriminate better than ABCD² alone.
Formula
Age, blood pressure, clinical features, duration and diabetes; 0 to 3 low, 4 to 5 moderate, 6 to 7 high.
- A · Age0–1
- B · Blood pressure0–1
- C · Clinical features0–2
- D · Duration of symptoms0–2
- D · Diabetes0–1
0–34–56–7
Age, blood pressure, clinical features, duration and diabetes; 0 to 3 low, 4 to 5 moderate, 6 to 7 high.
Items and score ranges
| Item | Finding | Points |
|---|---|---|
| A: Age | 60 or older | 1 |
| B: Blood pressure | Systolic 140 or more, or diastolic 90 or more | 1 |
| C: Clinical features | Speech disturbance without weaknessUnilateral weakness (with or without speech disturbance) | 12 |
| D: Duration of symptoms | 10 to 59 minutes60 minutes or more | 12 |
| D: Diabetes | Yes | 1 |
| Risk | Score | 2-day stroke | Patients |
|---|---|---|---|
| Low risk | 0 to 3 | 1.0% | 1,628 |
| Moderate risk | 4 to 5 | 4.1% | 2,169 |
| High risk | 6 to 7 | 8.1% | 1,012 |
Johnston 2007
Combined the earlier California and ABCD scores into one, derived in two cohorts (1,916 patients) and validated in four (2,893), to predict stroke within 2 days. The risks by score range are for all 4,809 patients.
Face-to-face scoring
In a pooled analysis, the score predicted best when scored by clinicians seeing the patient, and worst when taken retrospectively from emergency records.
NICE 2019
UK guidance (NICE 2019) advises against using ABCD² or similar scores to assess stroke risk or to decide how urgently to refer; everyone with a suspected TIA is to be seen by a specialist within 24 hours of symptom onset.
Test cases
3 published cases, each also a test case
- 2
- 3
- 4
3 published cases; the calculator reproduces every score.
Worked examples
Each example is also a test case: the calculator must reproduce the score the source reports before any change to it can be published.
Aphonia during a cesarean section: score 2
2 pointsA 31-year-old woman having a repeat cesarean section under spinal anesthesia with bupivacaine and fentanyl suddenly lost her voice and felt tingling over her face, without weakness. Her blood pressure at the time was 110/64 mmHg, and the aphonia resolved after 20 minutes. The authors scored the ABCD² as 2 and found no embolic source.
Source and detailsHide details
“ABCD2 score in this patient was 2 (speech disturbance without weakness [1 point] and duration of symptoms <60minutes [1 point]).”
Speech 1 and duration 10 to 59 minutes 1. The authors discuss intrathecal fentanyl as a possible cause, so this event may have been a mimic rather than a TIA.
Entered as: Age: Under 60 (0); Blood pressure: Below 140/90 mmHg (0); Clinical features: Speech disturbance without weakness (1); Duration of symptoms: 10 to 59 minutes (1); Diabetes: No (0).
Source: Ray BR et al., J Anaesthesiol Clin Pharmacol 2012 (PubMed · Free full text · DOI)
Aphasia after general anesthesia: score 3
3 pointsA healthy 45-year-old woman could not speak after waking from general anesthesia for a laparoscopic hysterectomy. The aphasia lasted about an hour, her voice was hoarse after that, and she spoke normally by 4 hours; imaging was normal. The authors scored the ABCD² as 3 and attributed the event to a psychoemotional reaction rather than a TIA.
Source and detailsHide details
“The “ABCD2” score in this patient was 3 (speech disturbance without weakness [1 point] and duration of symptoms > 60 minutes [2 points]).”
Speech 1 and duration of 60 minutes or more 2. The report does not give the blood pressure at assessment; the authors did not score it, so it is entered as below 140/90.
Entered as: Age: Under 60 (0); Blood pressure: Below 140/90 mmHg (0); Clinical features: Speech disturbance without weakness (1); Duration of symptoms: 60 minutes or more (2); Diabetes: No (0).
Source: Zhang J et al., Clin Case Rep 2021 (PubMed · Free full text · DOI)
Subdural hematoma mimicking TIA: score 4
4 pointsAn 82-year-old woman on warfarin for a mechanical mitral valve had episodes of left arm weakness and numbness after hitting her head on a car door. Her blood pressure was 128/68 mmHg and no diabetes was reported. TIA was suspected and the ABCD² was 4, but CT and MRI showed a small subdural hematoma; the episodes were transient deficits from the hematoma.
Source and detailsHide details
“ABCD2 score was 4 (age ≥60 years old, 1 point; weakness in one upper limb, 2 points; duration of symptoms, 10-59 minutes: 1 point).”
Age 1, unilateral weakness 2 and duration 1, as the authors scored it (the case text says the first episode resolved within a few minutes). She had treated hypertension, but the item scores the measured blood pressure (128/68 mmHg), not the history. A moderate score does not tell a TIA from a mimic; in a patient on anticoagulation after head trauma, imaging comes first.
Entered as: Age: 60 or older (1); Blood pressure: Below 140/90 mmHg (0); Clinical features: Unilateral weakness (with or without speech disturbance) (2); Duration of symptoms: 10 to 59 minutes (1); Diabetes: No (0).
Source: Takahashi N et al., Intern Med 2025 (PubMed · Free full text · DOI)
FAQ
6 questions and answers
- QWhat does ABCD² stand for?
- QWhat is a high ABCD² score?
and 4 more answers
Questions
What does ABCD² stand for?
+
Age (60 or older, 1 point), Blood pressure (140/90 mmHg or higher at first assessment, 1 point), Clinical features (unilateral weakness 2 points, or speech disturbance without weakness 1 point), Duration (60 minutes or more 2 points, 10 to 59 minutes 1 point) and Diabetes (1 point). The two D’s give the squared sign. The total runs from 0 to 7.
What is a high ABCD² score?
+
Across the cohorts of the 2007 study, a score of 6 or 7 was high risk (8.1% had a stroke within 2 days), 4 or 5 moderate (4.1%), and 0 to 3 low (1.0%). Many services used 4 or more to decide who was seen within 24 hours.
Should I still use the ABCD² score?
+
With care. A 2015 meta-analysis found that a score of 4 or more caught 87% of strokes within 7 days but was only 35% specific, and that 1 in 5 patients scoring below 4 had atrial fibrillation or a significant carotid stenosis. UK guidance from NICE (2019) advises against using scores such as ABCD² to assess stroke risk or decide how urgently to refer: every suspected TIA is to be seen by a specialist within 24 hours. US guidance (AHA/ASA 2021) still uses a score of 4 or more, as the CHANCE and POINT trials did, to pick out high-risk TIA for short-term dual antiplatelet treatment. The score is still a quick summary of risk factors, not a reason to delay assessment.
How is blood pressure scored?
+
From the first blood pressure taken after the event: a systolic of 140 or more, or a diastolic of 90 or more, scores 1 point.
What if the symptoms have not resolved?
+
Then it is not a TIA yet. Treat it as a possible acute stroke and follow the stroke pathway, since reperfusion treatment may be possible.
Does the score tell a TIA from a mimic?
+
No. In the 2015 meta-analysis, 35% to 41% of TIA mimics scored 4 or more. Migraine aura, seizures, syncope, low blood sugar and functional symptoms can all score points.
Further reading
7 references with PubMed and DOI links
7
references
4
free full text
From Johnston SC et al., Lancet 2007 to the newest case reports.
References
- Johnston SC, Rothwell PM, Nguyen-Huynh MN, Giles MF, Elkins JS, Bernstein AL, et al. Validation and refinement of scores to predict very early stroke risk after transient ischaemic attack. Lancet. 2007;369(9558):283-292. PubMed · DOI
- Giles MF, Rothwell PM. Systematic review and pooled analysis of published and unpublished validations of the ABCD and ABCD2 transient ischemic attack risk scores. Stroke. 2010;41(4):667-673. PubMed · DOI
- Wardlaw JM, Brazzelli M, Chappell FM, Miranda H, Shuler K, Sandercock PA, et al. ABCD2 score and secondary stroke prevention: meta-analysis and effect per 1,000 patients triaged. Neurology. 2015;85(4):373-380. PubMed · Free full text · DOI
- Amarenco P, Lavallée PC, Labreuche J, Albers GW, Bornstein NM, Canhão P, et al. One-year risk of stroke after transient ischemic attack or minor stroke. N Engl J Med. 2016;374(16):1533-1542. PubMed · DOI
- Ray BR, Baidya DK, Gregory DM, Sunder R. Intraoperative neurological event during cesarean section under spinal anesthesia with fentanyl and bupivacaine: case report and review of literature. J Anaesthesiol Clin Pharmacol. 2012;28(3):374-377. PubMed · Free full text · DOI
- Zhang J, Yang M, Dong H, Lu Z. Transient aphasia following general anesthesia in patient undergoing laparoscopic gynecologic surgery: a case report and literature review. Clin Case Rep. 2021;9(2):634-637. PubMed · Free full text · DOI
- Takahashi N, Mishima T, Nakamura D, Fujioka S, Tsuboi Y. Three cases of subdural hematoma with transient neurological deficits: importance of sulcal hyperintensity in magnetic resonance imaging fluid-attenuated inversion recovery images. Intern Med. 2025;64(7):1101-1106. PubMed · Free full text · DOI
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Which published the pooled validation analysis, with its current metrics.
MZ
About this page
Contributed by Dr. Meng Zhao (MD · Former Neurosurgeon · Medical AI Researcher), from the original publications listed here. Last updated November 13, 2026. LinkedIn
The calculator code is tested against every worked example on this page before each release.
This calculator supports, and does not replace, clinical judgment. It is meant for healthcare professionals and is not medical advice for patients. Report an error through the contact page.