Bimanual Motor Skill Learning in Acute Stroke

Overview

The subacute phase of stroke provides a window into how a lesion perturbs sensorimotor functions prior to reorganisation driven by plasticity and neurorehabilitation. The recovery from motor impairment has been extensively studied, but it is currently unknown whether motor skill learning (MSkL) is enhanced or impaired during acute stroke, especially bimanual motor skill learning (bim-MSkL), which likely requires more motor-attentional-cognitive resources than unimanual MSkL. The goals of this project are: to determine the neural substrates critical to achieve proximal and distal bimanual motor skill learning (bim-MSkL) by specifying whether (sub)acute stroke to different brain areas (cortical and subcortical) induce specific deficits in bimanual and/or distal bim-MSkL, which behavioral components are involved in bim-MSkL, and whether damage to the motor, sensory and inter-hemispheric pathways specifically impairs proximal and/or distal bim-MSkL.

Over 3 consecutive days, the patients will be evaluated and will train on the rehabilitation robot REAplan® (http://www.axinesis.com/) to assess proximal bim-MSkL and on the manual dexterity tool Dextrain Manipulandum (https://www.dextrain.com/) to assess distal bim-MSkL. For proximal bim-MSkL, patients will train over the 3 days on the serious game Circuit on the bimanual REAplan® and will be randomised to two different bimanual versions. By this means, the investigators will explore the components of bim-MSkL in acute stroke patients. The motor skill learning setup (Circuit) that was developed and successfully used in healthy individuals and stroke patients has already been implemented in the REAplan® environment and will be used as innovative serious games based on a speed/accuracy trade-off (SAT), allowing a detailed analysis of motor skill learning components (speed, accuracy, SAT, movement smoothness, dynamics...). For the serious game Circuit, who based on motor skill learning, the subjects will have to practice a complex circuit and move a cursor as quickly and accurately as possible by controlling the handles of the robot with both arms. For distal bim-MSkL, patients will train on a complex sequence of finger movements involving both hands. Each day, several successive repetitions of the sequence will be displayed, corresponding to one block. 3 to 6 blocks will be repeated, each separated by 30 sec of rest. After training on the third day, a new sequence will be repeated for 3 blocks to assess generalization. To explore the role of different brain structures in bim-MskL, Voxel-based Lesion Symptom Mapping (VLSM) based on high-resolution brain magnetic resonance imaging (MRI) scans, will be used to analyse the relationship between tissue damage and proximal/distal bim-MskL scores on a voxel-by-voxel basis. Diffusion Tensor Imaging (DTI) will quantify the integrity of several white matter tracts, allowing through correlation analyses to unveil the white matter tracts crucial to achieve proximal and/or distal bim-MskL. In addition, several "classical" clinical scales and tests will be used to evaluate overall motor-sensory-cognitive functions. In addition to the (sub)acute stroke patients, a group of healthy individuals who will not undergo MRI (n=60) will be enrolled as control group. Subjects in this group will also be randomized 1/1 in the two versions of the bimanual Circuit task on the REAplan® robot.