The burden of rapid eye movement (REM) sleep behaviour disorder is well documented, however the significance of isolated REM sleep without atonia is unclear. We evaluated the prevalence and predictors of RSWA in a sleep clinic population. We analysed data in three groups—patients meeting American Academy of Sleep Medicine (AASM) criteria for loss of REM atonia (RSWA), elevated REM EMG activity which did not meet AASM criteria (Elevated REM EMG) and those with no elevated REM EMG activity (normal). Analysis included 511 diagnostic sleep studies over 6 months. RSWA was identified in 36 (5.8%) and elevated REM EMG activity in 44 (8.6%) patients. The RSWA group, compared with the normal group, had a higher use of medications (anti-depressants, beta blockers and anti-cholinesterase inhibitor) OR 2.05 (95% CI 1.0–4.1), p = 0.04. Periodic limb movement indices in REM were different between groups: RSWA mean (95% CI) = 22.5/h, (11.0–33.9), elevated REM EMG = 8.6/h, (5.1–12.2), normal mean = 0.9/h (0.6–1.3), p < 0.0001. On multivariable analysis, male gender was also associated with RSWA OR 4.1 (95% CI 11.4–13). Body mass index (BMI) and apnoea–hypopnea index (AHI) were higher in the normal group. There were no between-group differences in age, Epworth Sleepiness Scale, Hospital Anxiety/Depression Scale scores. At our institution, there is a relatively high prevalence of RSWA and predictors include medication use, elevated REM PLMi and male gender. There is also a group of patients with elevated REM EMG activity who demonstrate similar characteristics to those meeting AASM criteria, who warrant further characterisation.

快速眼动 (REM) 睡眠行为障碍的负担有据可查，但无张力障碍的单独 REM 睡眠的意义尚不清楚。我们评估了睡眠诊所人群中 RSWA 的患病率和预测因素。我们分析了三组数据——符合美国睡眠医学会 (AASM) 的 REM 肌张力丧失 (RSWA) 标准的患者、不符合 AASM 标准的 REM EMG 活动升高（REM EMG 升高）以及 REM EMG 活动没有升高的患者（普通的）。分析包括超过 6 个月的 511 项诊断性睡眠研究。在 36 名 (5.8%) 患者中发现 RSWA，在 44 名 (8.6%) 患者中发现 REM EMG 活动升高。与正常组相比，RSWA 组使用更高的药物（抗抑郁药、β 受体阻滞剂和抗胆碱酯酶抑制剂）或 2.05（95% CI 1.0-4.1），p = 0.04。REM 的周期性肢体运动指数在组间不同：RSWA 平均值 (95% CI) = 22.5/h，(11.0–33.9)，REM EMG 升高 = 8.6/h，(5.1–12.2)，正常平均值 = 0.9/h ( 0.6–1.3)，p  < 0.0001。在多变量分析中，男性也与 RSWA OR 4.1 相关（95% CI 11.4-13）。正常组的体重指数（BMI）和呼吸暂停低通气指数（AHI）较高。年龄、Epworth 嗜睡量表、医院焦虑/抑郁量表评分没有组间差异。在我们机构，RSWA 的患病率相对较高，预测因素包括药物使用、REM PLMi 升高和男性。还有一组 REM EMG 活动升高的患者表现出与符合 AASM 标准的患者相似的特征，需要进一步表征。