A reliability study on brain activation during active and passive arm movements supported by an MRI-compatible robot

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Medical Robotics

Background:

• Assessing brain function in neurorehabilitation is difficult due to inconsistent patient task performance.
• Robotic devices offer a solution by standardizing task execution for reliable longitudinal brain monitoring.

Purpose of the Study:

• To identify the brain network activated during active and passive elbow movements using an MRI-compatible robot (MaRIA).
• To evaluate the reproducibility of this brain activation over time in healthy subjects.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to analyze brain activation during robot-assisted arm movements.
• Two fMRI analysis models were compared: one including movement onset/duration, and another adding force and range of motion.
• Reliability of brain activation was assessed using various statistical methods on individual and group data.

Main Results:

• Both active and passive movements elicited robust brain activation in motor, somatosensory, parietal, and premotor regions, including subcortical structures.
• Reliability was high for active movements across both fMRI models and statistical approaches.
• Passive movements also showed robust activation, with improved reliability when movement force and range were included in the analysis (model 2).

Conclusions:

• MRI-compatible robotic systems like MaRIA enable reliable longitudinal assessment of arm movement-related brain activation.
• This technology can significantly aid in evaluating therapies and understanding brain plasticity after neurological injury.