Sleep related injury and its correlates in isolated rapid eye movement sleep behavior disorder

To evaluate factors associated with sleep related injury (SRI) and persistent SRI (pSRI) in patients with isolated rapid eye movement sleep behavior disorder (iRBD).

This is a retrospective cohort study. A total of 388 patients with iRBD were involved for a comprehensive review of sleep related injuries. SRI is defined as a lifetime history of injurious behaviors to self and/or bed partner, and pSRI is considered if injurious symptoms continued to occur frequently (≥1/month). Correlations of SRI/pSRI with clinical, lifestyle and polysomnographic characteristics were analyzed.

Lifetime SRI was reported in 322 (83 %) patients (66.3 ± 8.5 years old, male 77.0 %), with 19.3 % having severe injuries, including fractures (2.5 %) and subdural hemorrhage (1.2 %), while 7.5 % required medical attendance. SRI was related to more severe depressive features (P_adj = 0.017), current alcohol drinking (P_adj = 0.014) and higher mentalis phasic and tonic EMG activity (P_adj = 0.042 and 0.048). After a mean follow-up of 5.1 years, 18.2 % of SRI patients (38/209) had pSRI despite intense treatment. Frequent nightmare at baseline (OR [95 % CI] = 1.43 [1.01, 2.03]), restless leg syndrome (OR [95 % CI] = 5.68 [1.42, 22.64]) and adult-onset sleepwalking (OR [95 % CI] = 2.52 [1.10, 5.76]) were associated with an increased risk of pSRI.

SRI is common in patients with iRBD and 18 % had pSRI despite intensive treatment, emphasizing the importance of bedside safety. The identification of risk factors for SRI and pSRI underscores the need for systematic clinical screening and targeted interventions for at-risk patients.