# Neuropsychological deficits in patients with favorable outcomes after middle cerebral artery infarction treated with thrombectomy

## TL;DR

This study shows that patients with right-side brain strokes may have hidden cognitive issues even if they seem to recover well.

## Contribution

The study reveals neuropsychological deficits in right MCA stroke patients with favorable functional outcomes, highlighting limitations of the mRS.

## Key findings

- Right-sided MCA infarctions had larger infarct volumes and higher rates of lost working ability.
- Right MCA patients showed impaired attention, longer reaction times, and subclinical neglect.
- Most right MCA patients exhibited mild cognitive impairment despite favorable mRS scores.

## Abstract

Functional outcomes following stroke thrombectomy are commonly measured by the modified Rankin Scale (mRS). Due to hemisphere-specific representation of neuropsychological function, the mRS might underestimate persisting functional deficits, particularly in large right-hemispheric strokes. This study aimed to assess infarct volumes and neuropsychological symptoms in patients with left- and right-sided middle cerebral artery (MCA) infarctions treated with thrombectomy, having a favorable outcome at 3 months. We hypothesized that patients with right-sided strokes are affected by larger infarct volumes and suffer from neuropsychological and cognitive impairment despite being classified as functionally recovered on the mRS.

The study cohort consisted of 105 patients with MCA infarctions treated with thrombectomy and a favorable outcome at 3 months after stroke according to mRS 0-1. The infarct volumes after thrombectomy were measured using imaging data. Consenting patients received follow-up examinations through telephone interviews and written questionnaires (Stroke Impact Scale-16, Short Form-36). Patients with the largest infarct volumes were additionally assessed with a neuropsychological test battery (Test of Attentional Performance – Mobility-Version, TAP-M) and the Montreal Cognitive Assessment.

The mean infarct volume was larger in patients with right-sided (23.3 mL) strokes compared to left-sided (8.5 mL) strokes (p < 0.05). Loss of working ability was reported by 24.3% of patients with right MCA infarctions and 2.9% of patients with left MCA infarctions (p < 0.05). Compared to age-dependent standard values, patients with right-sided MCA infarctions showed longer reaction times, impaired divided attention, and subclinical neglect to the left. Additionally, the majority of these patients showed mild cognitive impairment.

These findings indicate that patients with right MCA infarctions, being categorized as having a “favorable functional outcome” on the mRS, suffer from relevant neuropsychological deficits, subclinical neglect, and reduced quality of life.