Neurofeedback Training for Parkinson's Disease Is Not Monkey Business

• Published in: Applied psychophysiology and biofeedback 2011-12, Vol.36 (4), p.290
• Main Authors: H.c.h.m., Ingrid, Estevao, Dave, Vanwersch, Raymond A.P
• Format: Article
• Language: English
• Subjects: Analysis; Biofeedback training; Body weight; Medical research; Medicine, Experimental
• ISSN: 1090-0586

There is a growing interest in neurofeedback technologies as a treatment against neurological diseases. However, the field of neurofeedback has proceeded largely without validation due to the lack of control groups. For this reason, skepticism towards neurofeedback in the past has caused its delay as a new therapy. Therefore, from a translation point of view, it is recommended to perform neurofeedback research in a non-human primate model closely related to humans to rule out placebo effects and nonspecific factors, bridging the gap between non-validated empirical and standardized controlled research. Until now, all the present knowledge about the mechanistic aspects of neurofeedback training has been based on correlation studies of neurophysiology with real time fMRI. From these studies, it is known that neurofeedback training may influence the metabolic activity in the striatum. This can be very important because a decline in metabolic activity activates microglial cells that are involved in the maintenance of the neurodegenerative process found in Parkinson's disease (PD). Sensorimotor rhythm (SMR) training might also have advantages in counteracting the dyskinesia as found in PD by changing the thalamocortical circuits leading to a decrease of GABA release from the striatum to the thalamus as is described for patients suffering from ADHD. Indeed, there is a description of a PD patient who was able to control involuntary movements after SMR training (Thompson & Thompson, 2003). In our study, 10 marmoset monkeys were provided with two epidural bioelectric bipolar electrodes above the sensorimotor cortex for telemetric EEG registration. Half of these monkeys were trained with positive reinforcement on SMR (12-16 Hz) measured by online analyses of 1.28-s EEG epochs in 30-min sessions (sample frequency 125 Hz). Another group of 5 monkeys was trained using random EEG biofeedback and served as a negative control group. After 9-12 training sessions, the experimental phase of the study started. PD was induced by repeated MPTP injections (total dose 7 mg/kg) in all monkeys, and the training continued for one session each week. Three weeks after PD induction, a twice-daily treatment with L-dopa started (12.5 mg/kg po). During the whole experimental phase, the monkeys were daily observed on Parkinsonian signs, body weight was measured, and behavioral tests were performed once a week. The preliminary results showed that the SMR-trained monkeys exhibited less decrea