STUDY OBJECTIVES Sleep-related head jerks (SRHJ) are often considered as a physiological motor phenomenon, occurring mainly during rapid eye movement (REM) sleep. Their clinical relevance and links with other sleep parameters are unclear. We characterized the clinical and polysomnographic features of patients with excessive SRHJ and compare them to healthy controls and patients with isolated REM sleep behavior disorder (iRBD). METHODS Thirty patients (19 males, 27.5 y.o., 16.0-51.0) with a REM-HJ index >30/hour were identified over a period of five years. All had a video-PSG recording to characterize the SRHJ, to assess associations with other sleep parameters and to quantify phasic and tonic electromyographic activity during REM sleep, compared with 30 healthy controls and 30 patients with iRBD. RESULTS Five among the 30 patients had a primary complaint of involuntary nighttime head movements associated with sleepiness or non-restorative sleep. The mean REM-HJ index was 57.22/h ± 24.42, a non-periodic pattern, stable across the sleep cycles, and with a low between-test variability (for the 9 patients with two PSG assessments in untreated condition). REM-HJs were often associated with arousals (65.2%) and leg movements (38.1%) and less with respiratory events (9.6%), without association with increased phasic and tonic electromyographic activities. SRHJ were also found in 36.7% of controls and 56.7% of iRBD patients, but with a lower index in REM sleep (0.79/h ± 1.59 and 2.76/h ± 4.57). CONCLUSIONS Although SRHJ are frequent in the general population and with uncertain clinical significance, rare severe symptomatic forms should be individualized and eventually be categorized as a new sleep-related movement disorder, distinct from RBD and periodic leg movements.

中文翻译：

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睡眠相关的头部抽搐：走向一种新的运动障碍

研究目标 睡眠相关的头部抽搐 (SRHJ) 通常被认为是一种生理运动现象，主要发生在快速眼动 (REM) 睡眠期间。它们的临床相关性以及与其他睡眠参数的联系尚不清楚。我们描述了过度 SRHJ 患者的临床和多导睡眠图特征，并将其与健康对照和孤立的 REM 睡眠行为障碍 (iRBD) 患者进行了比较。方法 在五年内确定了 30 名 REM-HJ 指数 >30/小时的患者（19 名男性，27.5 岁，16.0-51.0 岁）。与 30 名健康对照者和 30 名 iRBD 患者相比，所有人都有视频 PSG 记录来表征 SRHJ，评估与其他睡眠参数的关联并量化 REM 睡眠期间的阶段性和强直性肌电活动。结果 30 名患者中有 5 名主诉与困倦或非恢复性睡眠相关的夜间不自主头部运动。平均 REM-HJ 指数为 57.22/h ± 24.42，是一种非周期性模式，在整个睡眠周期中保持稳定，并且测试间变异性较低（对于 9 名在未经治疗的情况下进行两次 PSG 评估的患者）。REM-HJs 通常与觉醒 (65.2%) 和腿部运动 (38.1%) 相关，与呼吸事件 (9.6%) 相关，与时相和强直肌电活动增加无关。在 36.7% 的对照组和 56.7% 的 iRBD 患者中也发现了 SRHJ，但 REM 睡眠指数较低（0.79/h ± 1.59 和 2.76/h ± 4.57）。结论 尽管 SRHJ 在一般人群中很常见并且临床意义不确定，