Feasibility and Acceptability of the Somnomat Casa Rocking Bed as a Stimulation Substitute for a Patient with Rhythmic Movement Disorder

Rhythmic Movement Disorder (RMD) is a parasomnia characterized by repetitive, rhythmic movements such as headbanging or body rocking. It typically occurs in infancy and early childhood, often disrupting sleep, and may occasionally persist into later childhood or, in rare cases, adulthood. Although its etiology remains poorly understood, RMD episodes may function as self-soothing behaviors to facilitate sleep. Current treatment options are limited, but vestibular stimulation, such as rocking, has shown potential to enhance sleep quality and reduce RMD symptoms. This study evaluated the feasibility, acceptability, and therapeutic potential of the Somnomat Casa, a robotic bed delivering vestibular stimulation, in a 14 -yearold male with RMD. Over a 22 -week protocol, including baseline, intervention, and washout phases, the bed applied varied frequencies $(0.25 \text{Hz}$ and 0.30 Hz) and directions (lateral and longitudinal) of rocking. Data collection included camera recordings to quantify RMD episodes, a specific Somnomat questionnaire to assess intervention acceptability, as well as sleep quality questionnaires and polysomnographies to capture sleep quality. The intervention demonstrated high acceptability, with the participant reporting improved sleep quality and willingness to continue using the bed. Peak RMD frequency decreased by 17 % during the final intervention compared to baseline, and temporal shifts in episode occurrence were observed during intervention phases. Polysomnography suggested potential changes in sleep architecture linked to vestibular stimulation. These findings support the Somnomat Casa as a promising non-pharmacological intervention for RMD, warranting further investigation in larger clinical trials.