# Lesion locations are associated with cognitive impairment after ischemic stroke in young adults

## TL;DR

This study finds that the location of brain lesions from strokes in young adults is linked to cognitive problems, with cerebellar and left hemisphere regions being especially important.

## Contribution

The study provides a detailed map of lesion locations in young stroke patients and their associations with cognitive impairment.

## Key findings

- Lesions in both hemispheres and cerebellar regions are linked to major vascular cognitive disorder.
- Aphasia is strongly associated with left fronto-temporo-parietal regions.
- The left angular gyrus is most associated with major vascular cognitive disorder.

## Abstract

•Stroke lesions associated with poorer cognitive performance are widely distributed.•Lesions in the cerebellum are also associated with poorer cognitive performance.•Lesion distribution may explain the variability in cognitive deficits after stroke.

Stroke lesions associated with poorer cognitive performance are widely distributed.

Lesions in the cerebellum are also associated with poorer cognitive performance.

Lesion distribution may explain the variability in cognitive deficits after stroke.

Stroke location is an important determinant of post-stroke cognitive impairment (PSCI). In young adults, a comprehensive map of lesion patterns and their relations to PSCI is lacking. This study aims to identify lesion locations associated with poorer cognitive performance in patients with stroke at a young age.

We conducted a multicenter prospective cohort study between 2013 and 2021, enrolling patients aged 18–49 years with first-ever ischemic stroke and a visible stroke lesion on MRI. Cognitive assessments were performed within six months post-stroke, covering seven domains. We categorized patients as having no/mild or major vascular cognitive disorder (VCD), defined as a Z-score < -2.0 in one or more domains. We assessed aphasia by the NIHSS language subscale. We performed multivariate lesion-symptom mapping to identify lesion locations associated with major VCD, poorer cognitive performance in each domain, and aphasia.

Among 522 patients (median age 44.3 years [IQR 37.7–41.5]; 257 [49.2 %] women), 168 (32.2 %) had major VCD. Lesions in both hemispheres and cerebellar regions were associated with presence of a major VCD, and lower performance in episodic memory, processing speed, executive functioning, language, and attention and working memory. Aphasia had the strongest relationship with left fronto-temporo-parietal regions, while the left angular gyrus was the region most associated with major VCD.

We show that lesion locations associated with poorer cognitive performance in young stroke patients are widely distributed, including cerebellar regions. This study showcases the complexity in the relationships between affected brain regions and cognitive symptoms, explaining the variability in post-stroke cognitive outcome.