Optimizing Sleep Disorder Diagnosis in Underserved Regions: Insights from Video-Polysomnography Analysis in Southern Brazil.

Video-polysomnography (VPSG) is indicated for cases of nocturnal motor behaviors, particularly rapid eye movement (REM) sleep behavior disorder (RBD), and different sleep complaints in the context of neurological disease, particularly neurodegenerative disease. In a location with limited VPSG availability, referral and poststudy diagnoses were reviewed to help create flow protocols for sleep centers in economically-disadvantaged areas. A total of 115 VPSG studies conducted at a public university-affiliated hospital in Porto Alegre, Southern Brazil, were divided into groups related to sleep complaints that were primarily motor (M; n  = 54) or non-motor (NM; n  = 61). Abnormal motor activity was more common in the M group, suggesting that clinical history was sensitive in identifying motor behaviors. However, while most M group referrals were related to RBD suspicion ( n  = 43; 79.6%), less than half of these were confirmed ( n  = 21; 48.8%). There was a high ( n  = 38; 70.4%) prevalence of obstructive sleep apnea (OSA) in the M group, with 14 (25.9%) subjects fully meeting the criteria for moderate-to-severe OSA. In cases of suspected RBD ( n  = 43), the rate of moderate-to-severe OSA ( n  = 20; 46.5%) was nearly the same as the rate of positive RBD diagnosis ( n  = 21; 48.8%). Prevalence of any severity OSA ( n  = 35; 81.4%) exceeded positive or incomplete findings for RBD ( n  = 28; 65.1%). The findings suggest that the suspicion accuracy for OSA and RBD could improve through more thorough history-taking in the prediagnostic workup. In world regions with limited VPSG availability, clinicians must recognize the likelihood of sleep apnea related to nocturnal motor activity. We suggest prioritizing type 1 polysomnography (PSG) to treat or exclude OSA rather than starting an empirical treatment for RBD while waiting for a VPSG study.