The ASCOD classification system 1, published in 2013, aims to define phenotypes of ischemic strokes for individual patients by assigning a degree of probability to each of the most common causes of this pathology.
It serves most strictly as a research tool but is also useful clinically as a mnemonic to consider common causes of ischemic stroke.
Compared to alternative classification systems that assign only one cause to each individual stroke and often have an "undefined" category, the ASCOD system allows classification of each stroke by detailing multifactorial causes and their relative probability of causation.
The ASCOD classification, not fully detailed here, offers objective criteria for each of the following diseases based on imaging, laboratory and clinical evaluations:
- includes criteria such as stenosis >50% of an artery supplying the ischemic territory, endoluminal thrombus or occlusion
- small-vessel disease
- cardiac pathology
- other causes
- ideally documented with MRI or CT
For each letter in the system, a grade is assigned:
- 1: the disease is present and can potentially be a cause
- 2: the disease is present, but the causal link is uncertain
- 3: the disease is present, but the causal link is unlikely
- 0: the disease is absent
- 9: the workup is insufficient to grade the disease
The current classification replaces the ASCO classification 2 published in 2009 with the addition of the letter "D" to take into account the importance of arterial dissection in the genesis of ischemic stroke, particularly in young patients.
- 1. Amarenco P, Bogousslavsky J, Caplan LR, Donnan GA, Wolf ME, Hennerici MG. The ASCOD phenotyping of ischemic stroke (Updated ASCO Phenotyping). (2013) Cerebrovascular diseases (Basel, Switzerland). 36 (1): 1-5. doi:10.1159/000352050 - Pubmed
- 2. Amarenco P, Bogousslavsky J, Caplan LR, Donnan GA, Hennerici MG. New approach to stroke subtyping: the A-S-C-O (phenotypic) classification of stroke. (2009) Cerebrovascular diseases (Basel, Switzerland). 27 (5): 502-8. doi:10.1159/000210433 - Pubmed