What This Means
This study followed 167 adults who had a first stroke caused by a blocked blood vessel in the brain, comparing those whose stroke affected the front (anterior) part of the brain's blood supply with those whose stroke affected the back (posterior) part. Three months later, each person took an in-person memory and thinking test (the Beijing version of the MoCA). About 55% of people with front-circulation strokes showed cognitive impairment, compared with about 35% of those with back-circulation strokes.
The difference remained after accounting for other factors, with front-circulation stroke linked to about twice the odds of impairment. It also held up when a stricter cutoff for impairment was used. Differences were seen in most thinking areas, including visuospatial/executive skills, naming, delayed recall, language, abstraction, and orientation, but not attention. This gap appeared even though overall disability levels were similar between the two groups.
This research suggests that where in the brain a stroke occurs may relate to the pattern and amount of later cognitive problems, and that disability scores alone may miss these differences. However, this was a single-center study with a modest sample, and the authors caution that the findings are group-level associations that do not prove the stroke location causes the differences or serve as a diagnosis of specific cognitive problems in an individual.