Margaret L. Walker, United States of America
Emory University Department of NeurologyAuthor Of 1 Presentation
GAMMA SENSORY FLICKER FOR PATIENTS WITH PRODROMAL ALZHEIMER’S DISEASE: A FEASIBILITY TRIAL
Abstract
Aims
We and collaborators discovered that flickering lights and sound at gamma frequency (40Hz) reduces Alzheimer’s Disease (AD) pathology and alters immune cells and signaling in mice. To determine the feasibility of this intervention in humans we tested the safety, tolerability, and daily adherence of extended audiovisual gamma Flicker stimulation and explored biological effects.
Methods
Ten patients with mild cognitive impairment due to underlying AD received 1-hour daily gamma Flicker using audiovisual stimulation for 4 or 8 weeks at home with a delayed start design. Primary outcomes were safety, tolerance, and daily adherence to gamma Flicker stimulation. Exploratory biological outcomes were also assessed including neural entrainment, amyloid beta and tau pathology, cytokines and immune factors, and default mode network functional connectivity at baseline and after 4 and 8 weeks.
Results
Gamma sensory stimulation resulted in no severe adverse events related to treatment. Of 17 screened and enrolled subjects, 16 found the stimulation tolerable even at high intensities. Average adherence rates during the study were 95.5% with all subjects having adherence rates greater than 88%. All participants’ neural activity entrained to stimulation. While this study was not powered to conclusively assess biological changes following gamma Flicker, we found preliminary evidence that gamma Flicker strengthened functional connectivity between nodes in the default mode network and altered cytokines and immune factors in the cerebral spinal fluid.
Conclusions
These findings show that prolonged gamma sensory Flicker is safe, tolerable, and feasible with preliminary indications of immune and network effects, supporting further study of gamma stimulation in AD.