Mal de Débarquement Syndrome (MdDS) is an under-recognized balance disorder, which is manifested by persistent false sensations of oscillatory self-motion (rocking/swaying) and/or pulling in a specific direction (gravitational pull). Patients with MdDS typically experience additional presumably secondary symptoms, such as heightened sensitivity to visual motion (visually induced dizziness, VID), physical motion (motion sickness, MS), and other debilitating physical, cognitive, or affective problems. MdDS was previously considered intractable, and only recently was a breakthrough made in the clinical laboratory with an introduction of a visual-vestibular therapy protocol, yielding a significant long-term improvement of symptoms, including complete remission, in about 50% of patients. However, the approach is limited in several ways. Firstly, there is a practical limitation in implementing the treatment protocol, which requires a specialized set-up for visual stimulation in a dedicated room. This research will address this limitation by testing the utility of virtual reality technology to implement the treatment protocol. Secondly, patients often retain residual symptoms of VID and MS susceptibility, which often act as a trigger for the recurrence of MdDS. This limitation will be addressed by supplementing the original approach with an additional treatment focusing on VID or MS susceptibility. Thirdly, although the original protocol focused on reducing rocking/swaying sensations, gravitational pull often co-occurs with such sensations, and some experience only that motion sensation. This limitation will be addressed by modifying the original protocol. Two hundred patients with MdDS will be recruited for the study. Bias will be controlled by randomized group assignment and the use of placebo treatments. Patients will be treated for 1-2 hours a day for 5 days. Patients will be followed for up to 6 months. The proposed study will facilitate improved outcomes for MdDS by broadening its treatment options.

Objectives This study aims to improve outcomes of MdDS by broadening its treatment options. Specifically, to improve access to the VOR readaptation treatment, the investigators will test the efficacy of VR goggles in generating visual motion to treat MdDS. If proven to be effective, MdDS patients can be treated locally in many vestibular therapy offices, not only for initial treatment but also for remedial or follow-up treatment when symptoms return. To improve long-term outcomes of MdDS, the investigators will evaluate the efficacy of the treatment of a complementary approach combined with VOR readaptation. The investigators hypothesize that an additional intervention that reduces (habituates) the velocity storage capacity will decrease sensitivity to physical movement and improves MdDS symptoms as well as limits symptom recurrence. In addition the investigators hypothesize that desensitization to visual stimuli can reduce visually induced dizziness frequently observed in patients with MdDS. The investigators will verify whether these complementary treatments will provide a better outcome compared to the readaptation treatment by itself. Lastly, to broaden the scope of the VOR readaptation treatment, the study will address the false sensation of gravitational pull commonly reported by patients. The investigators also hypothesize that a visual motion stimulus without cross-axis head motion can reduce this sensation.

Specific Aims Specific Aim 1: Evaluate the efficacy of VR goggles for VOR readaptation. One hundred patients with oscillatory self-motion sensations will be randomly assigned to undergo VOR readaptation with full-field OKS (Group 1, n=50) or VR goggles (Group 2, n=50). Immediate and up to six-month follow-up results will be compared.

Specific Aim 2: Evaluate the efficacy of habituation and visual desensitization combined with VOR readaptation. Sixty patients with oscillatory self-motion sensations will be randomly assigned to undergo VOR readaptation with full-field OKS combined with a habituation (Group 3, n=30) or visual desensitization (Group 4, n=30) protocol. Immediate and up to six-month follow-up results will be compared to those of Group 1.

Specific Aim 3: Treatment of gravitational pull sensation. The investigators estimate that 40 of 200 patients screened for this study will have a phantom sensation dominated by gravity pull, 20 with only that sensation. These patients will be randomly assigned to undergo OKS in a full-field (Group 5, n=20) or VR setting (Group 6, n=20). Immediate and up to six-month follow-up results will be compared.

How Research Will Be Introduced to Participants:

The study will be introduced to potential participants through public announcements such as ClinicalTrials.gov, referrals from clinicians, or direct contact by investigators to individuals who previously requested to be contacted for the opportunity to participate in an MdDS treatment study.

How Participants Will Be Screened:

Informed consent form will be emailed to individuals interested in study participation. Individuals will be contacted by the investigators over the phone and consented for study participation. Consented potential participants will receive intake forms via email with questions regarding the history and symptom characteristics of MdDS, age, sex, and general medical history. Investigators will review the returned intake forms to determine eligibility for study participation based on the inclusion/exclusion criteria described separately and a telephone interview for confirmation and clarification of the candidate's MdDS symptoms. A nystagmography test will then be requested to verify normal inner ear and central vestibular functioning. When candidates do not qualify for the study, screening data will be de-identified, and only those about MdDS symptom presentation, age, sex, and the reason for exclusion will be kept. Intake form and the nystagmography report of the candidates will be securely transferred to NYU for Dr. Catherine Cho to review. Dr. Cho will then conduct a telephone interview with each candidate, and provide PI with confirmation or denial of candidate eligibility, after which the information reviewed by Dr. Cho will be destroyed.

Inclusion Criteria:

• Conformable diagnosis of Mal de Débarquement Syndrome including significant improvement of symptoms with passive motion.

Exclusion Criteria:

• A history of abnormal inner ear or central vestibular function indicated by abnormal nystagmography test (abnormal saccades or pursuit, VOR suppression index <85%, no caloric response, decay time constant of response to rotation less than 10 seconds, spontaneous nystagmus).
• Confounding neurological disorders (e.g., multiple sclerosis, Parkinson's, epilepsy, blindness etc.).
• A history of leg, spine, or other injuries that affect their ability to stand or walk without assisting support.
• High level of anxiety as indicated by State-Trait Anxiety Inventory (≥75) and the Beck Anxiety Inventory (≥55).
• Claustrophobia.
• Patients previously treated with VOR readaptation technique are excluded.

All of the individual participant data collected during the trial, after deidentification.

Immediately following publication. No end date.

Investigators whose proposed use of the data has been approved by an independent review committee ('learned intermediary') identified for this purpose.

Any purpose. Proposals should be directed to sergei.yakushin@mssm.edu. To gain access, data requestors will need to sign a data access agreement. Data will be available for 5 years at a third party website (tbd).

The group assignment will be based on a random drawing of numbers prepared by Dr. Maruta, to the outcome of which he will be blinded. Dr. Cho (NYU) will interview each participant over the phone prior and at the completion of the final 6-month follow-up to independently record symptom severity scores as reported by the participants. Dr. Cho will be blinded to the type of the treatment that the participants received. Dr. Maruta will perform analyses of objective (posture, rotational test, VNG) and subjective (DHI, SVQ, VVAS, HADS, STAI etc.) data obtained during the treatment and at follow-ups. Dr. Maruta will be blinded to the participants' identity and the type of treatment received.