Biomedical engineer Annabelle Singer has been working on a noninvasive therapy for Alzheimer’s disease that uses flickering lights and rhythmic tones to modulate brain waves for the past decade. Through her research, she has found that this technique, known as flicker, could also be beneficial for patients with various other neurological disorders, including epilepsy and multiple sclerosis. Singer is now leading a new clinical trial to test her flicker technology on patients with epilepsy. In previous studies, Singer and her team showed that the lights and sounds, administered through goggles and headphones, had positive effects on patients.Headphones can have positive effects, as shown in animal studies and early human trials. A recent clinical trial for individuals with epilepsy revealed the precise impact of headphones and an unexpected discovery. The treatment was found to reduce interictal epileptiform discharges (IEDs) in the brain, which are large, intermittent electrophysiological events observed between seizures in epilepsy patients. These events manifest as sharp spikes on an EEG readout. This finding is both interesting and encouraging.Singer, who holds the McCamish Foundation Early Career Professor position in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, emphasized the significance of IEDs occurring not only in epilepsy but also in conditions like autism, multiple sclerosis, and Alzheimer’s. These abnormal electrical discharges can disrupt normal brain function and lead to memory impairment. The research findings by Singer and her team were recently published in Nature Communications.
The brain contains complex patterns of electrical activity known as brain waves or oscillations that are responsible for our cognitive functions.
Memories, thoughts, and emotions are all made up of oscillations in the brain. Singer is interested in using these oscillations for therapeutic purposes.
When exposed to specific frequencies of light and sound, the flicker treatment can prompt gamma oscillations in mice. This helps the brain activate microglia, which are responsible for removing beta amyloid. Beta amyloid is believed to be a key factor in Alzheimer’s pathology. The researchers are also studying the brain activity during treatment to confirm its effectiveness.
The trial patients were supervised by physician Jon Willie at the Emory University Hospital Epilepsy Monitoring Unit. (Willie is)ie, co-corresponding author of the study with Singer, is now at Washington University in St. Louis.) They were waiting for surgery to remove a part of the brain where seizures occur. Before that could happen, they had to undergo intracranial seizure monitoring — recording electrodes are placed in the brain to pinpoint the seizure onset zone and determine exactly which tissue should be removed. Then, patients and their care team wait for a seizure to happen. It can take days.”
“In human studies, we’ve used noninvasive methods like functional MRI or scalp EEG, but they have real downsides in terms of resolution,” Singer said. “Working withThe discovery of the potential impact on these patients was a significant breakthrough. These individuals suffer from epilepsy that does not respond to treatment, indicating that medications are ineffective for them.”
Path to Recovery
Researcher Singer’s team enrolled 19 patients in the study. The primary author of the research, Lou Blanpain, who was previously a Ph.D. student in Singer’s lab and is currently a medical student at Emory, administered flicker stimulation and used recording equipment on each patient.
“Since these patients already had implanted recording probes for clinical purposes, we were able to directly record brain activity,” Singer explained. “We have never been able to obtain recordings of this quality during flicker stimulation before.”
Previous studies have shown that flicker therapy can modulate the visual and auditory brain regions that are responsive to stimuli. However, a new study found that it also affects deeper brain regions such as the medial temporal lobe and prefrontal cortex, which are important for memory. Additionally, the study discovered that IEDs (inhibitory/excitatory dynamics) were decreasing across the brain in areas that had not been fully explored before. This has significant implications for the potential therapeutic use of flicker therapy in Alzheimer’s patients and suggests that it may have broader applications beyond primary sensory regions.
In future studies, we will explore other medical conditions and potential consequences.
