The following is a summary of “Validation of the RBD Symptom Severity Scale in the North American Prodromal Synucleinopathy Consortium,” published in the January 2024 issue of Neurology by Choudhury et al.

For assessing the severity of REM sleep behavior disorder (RBD), where vivid dreams trigger physical movements, researchers rely on the RBD Symptom Severity Scale (RBDSSS).

Researchers conducted a retrospective study within the North American Prodromal Synucleinopathy (NAPS) Consortium to evaluate the psychometric and clinimetric properties of the RBDSSS in patients with RBD.

They involved NAPS participants with polysomnogram-confirmed RBD and their bedpartners. Both participant and bedpartner versions of the RBDSSS were completed. 8 RBDSSS questions gauge dreams, sounds, movements, and injury risks. Participant scores (max 54) and bedpartner scores (max 38) were obtained by multiplying the frequency and severity scores for each question. During a clinical interview, a physician assessed the Clinical Global Impression Scale of Severity (CGI-S) and RBD symptom frequency. Descriptive, correlational, and item response analyses were conducted for scale validation.

The results showed 261 participants, RBDSSS-PT (participant) scored a median of 10 (4–18), while RBDSSS-BP (bedpartner) had a median score of 8 (4–15). The median CGI-S was 3 (3–4), suggesting moderate severity. Women with RBD showed lower RBDSSS-BP scores (6 vs 9, P=0.02), with no sex differences observed in RBDSSS-PT scores (8 vs 10.5, P=0.615). Positive correlations were observed between RBDSSS-PT vs. RBDSSS-BP (Spearman r_s = 0.561), RBDSSS-PT vs CGI-S (r_s = 0.556), and RBDSSS-BP vs CGI-S (r_s = 0.491, all P<0.0001). Item response analysis showed a high discriminatory value (range 1.40–2.12) for both RBDSSS-PT and RBDSSS-BP (1.29–3.47).

Investigators concluded that RBDSSS was validated as a reliable and valid tool for measuring RBD symptom severity.

Source: neurology.org/doi/10.1212/WNL.0000000000208008