Short-term adaptation to a simple motor task: a physiological process preserved in multiple sclerosis.

Area of Science:

• Neuroscience
• Neuroimaging
• Motor Control

Background:

• Short-term adaptation, characterized by reduced functional MRI (fMRI) response during repeated tasks, is a known physiological process.
• Its alterations in neurological disorders like multiple sclerosis (MS) remain largely uninvestigated.

Purpose of the Study:

• To investigate short-term adaptation during a repeated motor task in patients with MS compared to healthy controls.
• To determine if fMRI response adaptation is preserved in MS and if it changes over a one-year period.

Main Methods:

• Functional MRI (fMRI) data were analyzed from 55 controls and 56 MS patients at baseline, with follow-up scans on 33 controls and 26 MS patients.
• Participants performed a 1 Hz right-hand tapping task using standardized equipment across multiple European sites.
• Analysis focused on changes in brain activation patterns across four fMRI runs within a 25-minute period.

Main Results:

• A consistent linear decrease in brain activation (response adaptation) was observed from run 1 to run 4 in motor and sensory areas, including the primary motor cortex, supplementary motor area, and cerebellum.
• This linear activation decay was identical in both control and MS groups.
• The observed adaptation remained stable at the 1-year follow-up and was not influenced by disease progression in MS patients.

Conclusions:

• Short-term adaptation to a simple motor task is a preserved physiological process in individuals with multiple sclerosis.
• fMRI-based assessment of motor adaptation is a reliable method for studying brain function in MS.
• These findings suggest that the neural mechanisms underlying short-term motor adaptation are robust in the context of MS.