# RECRUITMENT OF THE CENTRAL NERVOUS SYSTEM IN DIFFERENT HAND TASKS IN PATIENTS WITH HAND DYSFUNCTION AFTER STROKE BASED ON FUNCTIONAL NEAR-INFRARED SPECTROSCOPY: AN EXPLORATORY STUDY

## TL;DR

This study found that simple hand movements stimulate more brain activity than arm cycling in stroke patients, suggesting better rehabilitation potential.

## Contribution

The study compares brain activation patterns during two hand tasks in stroke patients using fNIRS, revealing novel insights into rehabilitation effectiveness.

## Key findings

- Grasping tasks increased brain activation more than handbike tasks in key regions like motor and sensory cortex.
- Grasping also enhanced functional connectivity between the prefrontal cortex and motor areas compared to handbike tasks.
- Both tasks showed significant brain activation increases compared to resting state, indicating neural recruitment during rehabilitation.

## Abstract

This study aimed to examine the central nervous system activation in stroke patients with hand dysfunction during various hand tasks, reflecting central nervous system recruitment.

A single-centre cross-sectional observational study.

This research selected stroke patients with hand dysfunction hospitalized in the authors’ hospital from October 2022 to November 2023. Participants were aged 25–75 years, with a post-stroke duration ranging from 2 to 24 weeks.

A 35-channel functional near-infrared spectroscopy system was used to record cortical activity during the resting state, affected-hand grasping tasks, and hand-crank cycling tasks. The study compared the average brain activation extent and functional connectivity between grasping and handbike tasks, focusing on the primary sensorimotor cortex, dorsolateral prefrontal cortex, primary motor cortex, and primary somatosensory cortex as regions of interest.

Comparative analysis of brain region activation revealed significant increases in activation across all regions of interest compared with the resting state (p < 0.001). When comparing grasping with handbike tasks, significant increases in activation were observed in all regions of interest except the right primary somatosensory cortex (p < 0.05). Additionally, the right dorsolateral prefrontal cortex exhibited stronger functional connectivity with bilateral primary motor cortex, primary sensorimotor cortex, and left primary somatosensory cortex during the grasping task compared with the handbike task (p < 0.05).

This study shows that grasping tasks recruit cognitive, sensory, and motor cortex activities in stroke patients with hand dysfunction relatively higher than handbike tasks.

After a stroke, many people have difficulty using their hand. We used a safe, portable brain scanner called fNIRS to compare 2 exercises: repeatedly opening and closing the hand, and using an arm-cycling machine. We found that both activities increased brain activity, but the hand movement stimulated more areas involved in motion, feeling, and thinking, and helped different brain regions communicate better. This suggests that simple hand opening and closing practice may be especially helpful for brain recovery after a stroke. Our results can assist therapists in choosing more effective rehabilitation methods.