Effect of MRgFUS treatment on cortical activity in Parkinson's disease: a fNIRS study

Abstract

In this paper, a new combined approach, based on Magnetic Resonance-guided Focused Ultrasound Surgery (MRgFUS) technique and functional Near Infrared Spectroscopy (fNIRS), was applied for treatment and monitoring of patients affected by bilateral Parkinson’s disease (PD). On one side, MRgFUS enables non-invasive thalamotomy by combining FUS for tissue ablation and MR for targeting and monitoring. On the other side, fNIRS allows to monitor, non-invasively and without strict motion restriction even in a daily life environment, cortical neural activity related dynamics of both oxygenated and deoxygenated haemoglobin (HbO and HbR, respectively). In particular, the changes of cortical activation pattern in PD patients, with respect to age matched healthy control subjects, were analysed, while performing left and right hand finger tapping (LFT and RFT, respectively), before MRgFUS treatment, and at two different time intervals after the treatment. By comparison with the pre-treatment session, significant activations were predominantly observed one week after the treatment, with patterns recalling those of control group, and partially lost one month later, likely because of the neurodegenerative nature of PD. In addition, activations were more marked for LFT task, being the treatment performed on the right hemisphere. These results appear promising in view of the application of fNIRS for neurorehabilitation, especially in those clinical settings where traditional neuroimaging techniques cannot be applied.