The SOMIRBD study one year later: feasibility, acceptability, and preliminary findings of a web-based screening model...

Isolated rapid eye movement sleep behavior disorder (iRBD), affecting 1% of the general population, is a strong prodromal marker of α-synucleinopathies, but remains underdiagnosed. Scalable screening strategies may facilitate the identification of individuals requiring specialist assessment. We report preliminary findings from the SOMIRBD study, focusing on the feasibility and acceptability of web-based screening, the characteristics of the screened population, and initial clinical assessment outcomes.

SOMIRBD is an ongoing longitudinal, population-based study recruiting healthy adults aged ≥18 years through a web-based questionnaire. The questionnaire included demographic and clinical information, the RBD Screening Questionnaire (RBDSQ), Epworth Sleepiness Scale (ESS), and selected prodromal markers of α-synucleinopathies. Participants scoring ≥5 on the RBDSQ were invited to undergo neurological and neuropsychological assessment.

Of 166 individuals accessing the survey, 150 provided informed consent, and 145 completed the questionnaire. Mean age was 42.2 ± 17.2 years, and 65.5% were women. Questionnaire acceptability was high (mean appreciation score, 4.7 ± 0.5/5). Forty-six participants (31.7%) had RBDSQ scores ≥5, while 32 (22.7%) had excessive daytime sleepiness (ESS>10). RBDSQ positivity was associated with excessive daytime sleepiness (33.3% vs. 17.7%; χ² = 4.26, p = 0.039). Fourteen of 46 RBDSQ-positive participants underwent clinical and cognitive assessment. One participant was classified as cognitively impaired. The mean PSQI score was 6.54 ± 2.40, with 61.5% of participants exceeding the conventional cutoff for poor sleep quality (PSQI>5). Clinical iRBD was diagnosed in two (14.3% of those assessed; 4.3% of all RBDSQ-positive participants), and both were cognitively unimpaired.

Preliminary findings support the feasibility and acceptability of web-based population screening for iRBD. However, the limited specificity of RBDSQ positivity highlights the need to integrate questionnaire-based screening with additional clinical and neurological information. Ongoing recruitment and longitudinal follow-up will enable the development of improved strategies for identifying individuals at increased risk of α-synucleinopathies.