Every time a neuron communicates with another cell, a little burst of electricity courses through the brain to power the message. The synchronization of this electrical activity gives rise to rhythmic voltage fluctuations travelling across brain regions, known as brain waves. In Parkinson's disease, dopaminergic neurons die off, causing brain waves to be out of tune. This can result in stiffness, uncoordinated movement and lesser-known non-motor issues such as depression and disrupted sleep.
Frequency stimulation approaches – specifically deep brain stimulation and meditation – are believed to target both the physical and mental aspects of the illness. Current research suggests that frequency stimulation is an additional tool to treat Parkinson's disease, with patients highlighting the benefits of its implementation.
The mental aspects of the disease are generally overlooked and are often the most effective in improving a patient's quality of life.
What are brain waves?
Brain waves are fluctuating electrical voltages in the brain, measuring just a few millionths of a volt; there are five widely recognized brain waves. Gamma waves are associated with higher brain functions like cognition and memory. Alpha waves, which can boost creativity and reduce symptoms of depression, are more dominant as we become drowsy and our eyes close. Theta waves are often observed in deep states of meditation and are associated with implicit learning, information processing, and making memories. Delta waves are associated with the deepest levels of relaxation and restorative, healing sleep. Delta wave imbalances are prominently seen in brain injuries, learning problems, inability to think, and severe ADHD. Beta waves, the most common daytime brain waves, are associated with engaging activities such as problem-solving and other cognitive tasks. Beta wave disruptions are present in Parkinson’s disease.
A surgical approach
Deep brain stimulation involves the insertion of electrodes into specific brain regions, through which electrical impulses are sent to regulate abnormal electrical activity. Lower brain frequencies are known to inhibit movement, while higher brain frequencies are known to promote movement.
Deep brain stimulation is currently limited to patients who respond poorly to dopaminergic drugs, do not have dementia and are relatively young. The risk of infection also provides a limitation to its use, but overall deep brain stimulation is considered a surgical procedure with low risk for infection.
If successful, deep brain stimulation can be long-lasting, remaining effective for 15 years. A study in 2021 by Bove et al. details that, with deep brain stimulation, there are significant improvements in motor symptoms such as dyskinesia (75 % decrease) and a substantial reduction in the need for dopaminergic drugs (50.6 % decrease) for Parkinson's patients. Unfortunately, the natural progression of the disease means motor and non-motor symptoms will continue to worsen despite deep brain stimulation. Still, this study shows that improved quality of life was maintained, with emotional function improving by 13.6 % and social function improving by 29.9 %. Thus, patients acknowledge the mental benefits of deep brain stimulation despite Parkinson’s disease's progressive nature.
A non-invasive approach
Social awareness of improved mental health as a result of consistent implementation of meditation has increased over the years. Current research supports this view, stating that cognitive performance, mindfulness skills, compassion, empathy, and positive emotions improved in patients suffering from poor mental health. The use of meditation for improving physical outcomes needs to be established better.
Yoga Nidra is a form of meditation that is believed to replace beta-wave frequencies with alpha-wave and theta-wave frequencies. It has not been determined scientifically whether Yoga Nidra amplifies the response of these non-beta wave frequencies. However, its effects appear promising. A voice guides the meditation over music, and the listener is directed to shift their attention to different parts of their body. One Parkinson's patient described being able to remain "still", meaning they could lay perfectly flat on their back for an hour during the meditation. Typically, they would have to move their body due to muscle stiffness, rigidity and pain. The placebo phenomenon cannot be negated in this case. Still, this patient's meditation testimonial does indicate that stimulation of certain brain waves could negate the abnormalities exhibited by other brain waves. This is hypothetical, of course, but the body is physiologically known to implement compensatory mechanisms in disease states and perhaps only requires further stimulation. Thus, "focussing on the positive" may indeed be literal.
What's next?
The offset of beta-wave frequencies via direct (deep brain stimulation) or indirect (meditation) means has grounds for improving both the physical and mental symptoms associated with Parkinson’s disease. Whereas deep brain stimulation blocks electrical signals to dampen beta waves, meditation activates non-beta waves. Fully understanding brain waves in the context of frequency stimulation will be the step required to understand not just Parkinson’s disease but other brain diseases as well. Developing future technologies to simultaneously block and activate different brain waves to target motor and non-motor symptoms associated with Parkinson’s disease is an exciting research field, so watch this space.
© Elizabeth Arrowsmith & Dr Victor Dieriks