Neuroradiology · Acute ischaemic stroke · Original 2008 score
Posterior Circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS)
A 10-point topographic score quantifying early ischaemic change within the posterior circulation, with additional weighting for the pons and midbrain.
Purpose
To quantify the extent of early posterior-circulation ischaemic change on CT angiography source images or diffusion-weighted MRI and support prognostic assessment, particularly in basilar artery occlusion.
| Region | Scoring unit | Deduction when involved | Maximum deduction |
|---|---|---|---|
| Thalamus | Left and right scored separately | 1 point per affected side | 2 points |
| Occipital lobe | Left and right scored separately | 1 point per affected side | 2 points |
| Cerebellum | Left and right scored separately | 1 point per affected side | 2 points |
| Midbrain | Scored as one region | 2 points for any involvement | 2 points |
| Pons | Scored as one region | 2 points for any involvement | 2 points |
How to use it
- Begin with 10 points and subtract points for every region showing acute ischaemic change.
- A score of 10 indicates no visible ischaemic change in the scored regions; progressively lower scores indicate more extensive involvement.
- The paired thalami, occipital lobes and cerebellar hemispheres contribute 1 point per side.
- The pons and midbrain are weighted more heavily, with a 2-point deduction for involvement of each structure.
- Lower baseline pc-ASPECTS is associated with a greater likelihood of an unfavourable functional outcome, but reported prognostic and treatment-selection thresholds vary across studies.
Common mistake
Do not subtract 2 points separately for each side of the pons or midbrain: each is a single 2-point region. Also remember that pc-ASPECTS starts at 10 and decreases as the extent of ischaemia increases.
Exam pearl
Remember the allocation as 6 peripheral paired regions contributing 1 point each, plus 2 points each for the pons and midbrain: 6 + 2 + 2 = 10.
Viva questions
- What is pc-ASPECTS?
- pc-ASPECTS is a 10-point semiquantitative score used to describe the extent of early ischaemic change in predefined posterior-circulation regions.
- Which anatomical regions are included in pc-ASPECTS?
- It includes both thalami, both occipital lobes, both cerebellar hemispheres, the pons and the midbrain.
- How is pc-ASPECTS calculated?
- Start with 10 points. Subtract 1 point for each affected thalamus, occipital lobe or cerebellar hemisphere, and subtract 2 points for involvement of the pons or midbrain.
- Why are the pons and midbrain given greater weight?
- They are clinically critical brainstem structures, so involvement of either region produces a 2-point deduction rather than the 1-point deduction used for each paired peripheral region.
- What does a pc-ASPECTS of 10 mean?
- It means that no acute ischaemic change is visible within any of the predefined pc-ASPECTS regions on the imaging sequence being scored.
- How should a low pc-ASPECTS be interpreted?
- A lower score represents more extensive posterior-circulation ischaemia and is associated with a higher likelihood of an unfavourable functional outcome. It should be interpreted with the clinical findings, vascular imaging and the treatment-selection criteria being used.
- What is a common scoring error involving the brainstem?
- A common error is subtracting 2 points for each side of the pons or midbrain. Each structure is scored as a single region and contributes a maximum deduction of 2 points.