A recent article on nature.com discussed “brainwave therapy”. Non-invasive procedures to tune brain oscillations that could in future be an effective alternative to drugs for conditions such as visual snow.
Neuronal Oscillations And Neurological Conditions
There is increasing evidence and understanding about neuronal oscillations for their role in neurological conditions.
- Bipolar disorder
- Neuropathic pain
- Parkinson’s disease
- Tourette syndrome
Weakened gamma oscillations have also recently been observed in a patient with visual snow. It is suspected that these may critically contribute to the pathophysiology of the condition.
Some of the same techniques used to explore neuronal oscillations and understand these conditions are also helping to advance “brainwave therapy” as a treatment approach for complex neurological disorders.
Neurofeedback (EEG Biofeedback)
Biofeedback is when bodily responses are measured to give feedback and allow you to start to control those functions better – e.g. muscle tension. Neurofeedback is the brain equivalent.
It involves brainwaves being measured via electrodes and an electroencephalogram (EEG). This identifies how the brainwaves change in response to certain stimuli. Signals can then be introduced (usually in sound/video form) that help promote positive brainwave activity and discourage negative brainwave activity.
Neurofeedback is effectively intended to teach you to control your brainwaves. It has been used to treat various conditions, including a few that are sometimes comorbid with visual snow: ADHD, anxiety, depression.
Here the change in brain wave activity is itself intended to produce a physiological change. Neuroplastic changes have indeed been observed following neurofeedback. But because it relies on neuroplasticity, issues are that neurofeedback both takes time to take effect and that the effects can wear off with time. Further underlying biological causes are not necessarily being addressed.
What Does A Neurofeedback Session Look Like
Optogenetics combines optics and genetics and in contrast to neurofeedback is a biological technique. Genetically engineered proteins that react to light are used to allow individual neurons to be controlled and monitored. Optogenetics is being used to advance our understanding of brain function and visual perception. It is also helping to develop light-based therapy.
In 2009 a study using optogenetics found that light pulses could be used to drive gamma oscillations in a mouse brain. A 2016 study with some of the same research team demonstrated that stimulating gamma brainwaves with light flicker could actually change gene expression in mice with Alzheimer’s and affect cellular metabolism. Alzheimer’s being a condition where there is weakened gamma wave activity. The researchers in that study found a 67% reduction of plaques formed from the amyloid-β peptide in the visual cortex, along with a reduction in tau proteins – two hallmarks of the Alzheimer’s.
A limitation for such treatment applications (perhaps less so potentially for visual snow) is that they are effective at the visual cortex. To reliably target regions beyond the visual cortex, methods such as transcranial electrical stimulation are being explored.
Light-Based Therapy For Alzheimer’s Disease
Transcranial electrical stimulation
Refers to the non-invasive application of electrical currents to the brain via electrodes. The application of current can be modified e.g. amplitude or repetition frequency, this can help target different brain-regions and create specific outcomes.
One relevant example is Transcranial alternating current stimulation (TACS). Among other things TACS may be able to modulate the excitability of the visual cortex.