Three-territory sign (brain)
Citation, DOI & article data
The three-territory sign is a radiological sign described in ischemic stroke and is highly specific to hypercoagulability due to malignancy (Trousseau syndrome) being the etiology. However, this sign is not pathognomonic, and may be seen with cardioembolic stroke (e.g. due to atrial fibrillation or endocarditis) or stroke due to other prothrombotic states (e.g. due to COVID-19) 1-4.
The three-territory sign describes ischemic strokes involving three vascular territories including involvement of the bilateral anterior and posterior circulations 1-4. Often, the individual ischemic strokes are small, rather than being large vessel occlusions 3. The sign is best appreciated with diffusion-weighted imaging MRI 1-4.
In one study, the three-territory sign was found to be highly specific (96.4%) but not sensitive (23.4%) for hypercoagulability due to malignancy (Trousseau syndrome) 1. Notably, in the same study, the three-territory sign was six times more likely observed in patients with underlying malignancy when compared to patients with underlying atrial fibrillation who may have had multi-territory cardioembolic ischemic stroke 1.
- 1. Nouh A, Staff I, Finelli P. Three Territory Sign: An MRI Marker of Malignancy-Related Ischemic Stroke (Trousseau Syndrome). Neurol Clin Pract. 2019;9(2):124-8. doi:10.1212/CPJ.0000000000000603 - Pubmed
- 2. Finelli P. MR Three-Territory Sign in Cancer-Associated... : The Neurologist. LWW. 2021;27(2):37-40. doi:10.1097/NRL.0000000000000356
- 3. Finelli P & Nouh A. Three-Territory DWI Acute Infarcts: Diagnostic Value in Cancer-Associated Hypercoagulation Stroke (Trousseau Syndrome). AJNR Am J Neuroradiol. 2016;37(11):2033-6. doi:10.3174/ajnr.A4846 - Pubmed
- 4. Bhatele P, Das A, Pandit A, Radhakrishnan D, Srivastava A. Three Territory Sign in COVID-19. Acta Neurol Belg. 2022;:1-2. doi:10.1007/s13760-021-01842-8 - Pubmed