Targeted brain activation using isometric motor tasks during functional magnetic resonance imaging

Abstract

Over 0.9% of the population suffers from a movement disorder. The pathophysiology of most movement disorders remains unknown, thereby impairing effective diagnosis and consequently effective treatment. Abnormal activity of the cerebellum (CBL) and basal ganglia (BG) has been implicated in many movement disorders, including Parkinsonian tremor and dystonia. Selectively activating these brain regions may help identify pathological changes and expedite diagnosis. Dedicated pairs of isometric wrist flexion tasks with and without visual feedback of the exerted torque were devised to selectively activate the CBL and BG in healthy subjects (N=5), while ensuring safety and keeping artifacts to a minimum. Increased activity in CBL and BG (putamen) was found during a constant torque task with visual feedback compared to a constant torque task without visual feedback. Increased BG (caudate nucleus) activity was found when comparing a torque task with visual feedback where flexion and rest were rapidly alternated, to the same task without visual feedback. Increased activity in the CBL was found during a constant torque task with visual feedback with an added visual error compared to a constant torque task with normal visual feedback. This study shows that specific pairs of motor tasks using the wrist and simple MR-compatible equipment allow for targeted activation of CBL and BG and paves the way for more extensive research and eventually improved diagnosis of patients.BMBioMechanical EngineeringMechanical, Maritime and Materials Engineerin