Peer Reviewed

Symptom Reduction in MdDS with Attenuation of the Velocity Storage Contribution

New Research

Below is a summary of a recent study into Mal de débarquement syndrome (MdDS) and how to reduce symptoms for people with this condition.

Symptom Reduction in MdDS with Attenuation of the Velocity Storage Contribution

Mal de débarquement syndrome (MdDS) is an under-recognized and little-understood chronic vestibular disorder primarily characterized with a phantom sensation of oscillatory self-motion or gravitational pull. MdDS typically onsets after prolonged exposure to passive motion of a transport vehicle, and is associated with a failure to readjust to a stable environment after adapting to being in motion. MdDS can be difficult to treat, but the chance of a positive outcome has improved recently with the discovery that a central vestibular function, known as velocity storage, may be ill-adapted in patients with this condition. Velocity storage is a center of multimodal sensory integration that contributes to eye and postural reflexes and spatial perception. As such, a visual-vestibular therapy technique aimed to correct the spatial orientation action of velocity storage is becoming recognized as an effective treatment for MdDS. However, this treatment may not prevent subsequent symptom relapse triggered by re-exposure to prolonged passive motion or provocative visual stimuli.

Presently, it was postulated that decreasing, as opposed to correcting, the ill-adapted velocity storage contribution in the brain pathways could also reduce symptoms of MdDS. Velocity storage may be useful in some contexts when correctly functioning, but having little velocity storage capacity by itself is not a known cause of functional impairment. To decrease the contribution of velocity storage, the investigators applied a visual-vestibular therapy technique modified from one that was originally developed for reducing proneness to motion sickness.

To contrast the effects of the two treatment approaches, 43 patients with MdDS were randomly assigned to two groups and followed for 6 months. Confirming previous studies, most patients (80%) in the group that underwent the spatial readaptation treatment initially experienced a substantial improvement in their symptoms, but the treatment did not prevent a symptom return in the long term. The new therapy technique also demonstrated a significant treatment effect, although with a much smaller initial impact. Just nearly one-half of the patients (43%) in the group that underwent the new treatment reported a substantial improvement in their symptoms. Remarkably, however, most of the responders to this treatment continued to experience reduced symptoms in the long term. Therefore, if initially effective, the treatment also had a long-term preventative effect against symptom relapse.

In summary, the study suggests that decreasing the presumably ill-adapted velocity storage contribution in the brain pathways can reduce symptoms of MdDS in some patients and that the treatment has a lasting effect. This new treatment approach shows promise as a long-term remedy for MdDS that can complement the spatial readaptation approach.

Source: Maruta J, Cho C, Raphan T, Yakushin SB. Front Rehabil Sci. 2024 Feb 29;5:1331135