Basal ganglia as an fMRI motor neurofeedback target in Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by motor impairments. While pharmacological treatments offer symptom alleviation, their long-term effectiveness is insufficient. Deep Brain Stimulation (DBS) is a neurosurgical treatment that targets brain pathways to alleviate motor symptoms in PD. It is a highly invasive procedure and carries associated risks. This prompts investigation of non-invasive alternatives, such as real-time functional Magnetic Resonance Imaging (rt-fMRI) neurofeedback (NF). This work investigates the feasibility of using the basal ganglia, more specifically the putamen, a key structure in the motor network, as a potential NF target region. Two rt-fMRI studies were conducted: (i) Twelve healthy individuals participated in a single-blind, crossover study involving one MRI session targeting the putamen and the supplementary motor area (SMA) in separate runs. (ii) Twelve PD patients followed the same protocol but with three MRI sessions. We investigated whether participants could learn to voluntarily control brain activity through NF training. The PD patients successfully recruited the putamen during NF-reinforced motor imagery, which was also found at trend level in the healthy participants. We found no learning effect and no difference in putamen activation when it was directly targeted versus when the target signals came from the SMA. Overall, widespread cortical and subcortical areas involved in motor control were activated during neurofeedback. This study demonstrates for the first time that PD patients can modulate putamen activity through NF training, supporting its potential as a non-invasive neuromodulation target. This opens opportunities for integrating invasive and non-invasive neuromodulation for PD treatment.