The main device class used in this study will be an app that was designed by one of the investigators. The app is called WAVES and can be run on either an Android or iOS platform. The program presents a split screen of flashing lights with a different frequency on each half screen. The frequency of the lights can be changed according to either standard parameters or parameters set by EEG metrics. Audio stimulation will also be added in a second phase of the study. The audio stimulation consists of clicks given to each ear at different frequencies.~The study will have several stages. The participants will be told what stage of the project they will be participating in.~Stage 1: Open-label feasibility-this stage will include about 10-15 individuals who will be test participants for new protocols. This may include change in frequency of stimulation around a new baseline such as the individual theta frequency or the individual alpha frequency. All session parameters will be restricted, e.g. no more than 40-minutes of total stimulation per session.~Stage 2: Sham controlled single-blind randomized onsite. This stage will include participants who receive up to 40-minutes of visual stimulation given either through a protocol determined in Stage 1 as an effective paradigm or as random frequency stimulation. The participants will be blinded to study allocation. The principal investigator will not be blinded in order to have tighter oversight on safety.~Stage 3: Sham controlled double-blind randomized at home with cross over study. This stage will involve sending the participants home with a smartphone app and pre-fitted head mounted virtual reality frame. The participants will receive a kit that contains the accessories and smartphone. Allocation will be 1:1 real to sham stimulation. After a preset trial duration (generally 2-weeks) the participants who were give sham stimulation will be cross-overed to real stimulation. The individuals who underwent real stimulation will be cross-overed to sham stimulation for 2 weeks. Both will then be given the option of doing 2 weeks of open label stimulation and then tapered to off over 2 weeks. This will provide an assessment of stimulation efficacy of 2 weeks vs 4 weeks as well as the sham response rate. Each week of sessions entails 5-10 sessions per week.~The participants will be completing online study questionnaires through a personalized weblink on RedCap or SurveyMonkey.~EEG recordings will be made at baseline, conclusion, and in between sessions to monitor the correlation between symptoms and EEG features.
This study will be recruiting individuals with Mal de Debarquement Syndrome (MdDS), a disorder caused by entrainment to oscillating motion that leads to persistent oscillating vertigo. The typical triggers for MdDS are sea and air travel. Prior studies on MdDS have shown that functional connectivity measured by both EEG and fMRI decreases when symptoms of MdDS improve. This study seeks to use asynchronous visual and auditory stimulation provided through a smart-phone app (WAVES) administered through virtual reality goggles to modulate the vertigo in MdDS with the hypothesis that these stimuli can desynchronize functional connectivity.