Effect of Periodic Limb Movements in Sleep on Sleep Structure in Stroke Patients

Abstract

Background Sleep disorder is a common complication of stroke with various clinical manifestations. Among them, periodic limb movements in sleep (PLMS) are characterized by repetitive and stereotyped limb movements during sleep. Due to limited clinical date, the pathogenesis of PLMS and their impact on prognosis of stroke are still in the exploratory stage. Studies about the effect of PLMS on sleep in stroke patients are few in worldwide. Objective To explore the sleep structure of stroke patients with PLMS. Methods From December 2020 to February 2022, a total of 81 stroke patients with sleep disorders were selected from the Second Affiliated Hospital of Zhengzhou University, in which polysomnography (PSG) was performed. The clinical information and PSG sleep monitoring data of patients were collected. According to the Periodic Limb Movement Index (PLMI) , the patients were divided into non-PLMS patients (control group, PLMI<15 times/h) and PLMS patients (experimental group, PLMI≥15 times/h) . The parameters between two groups were compared. These parameters include awake PLMI, sleep efficiency, proportion of stage N1 sleep in total sleep time, proportion of stage N2 sleep in total sleep time, proportion of stage N3 sleep in total sleep time, REM sleep in total sleep time, sleep apnea hypopnea index (AHI) , sleep latency, arousal index, and periodic limb movement arousal index (PLMAI) . Moreover, the correlation between PLMS and sleep structure and related parameters was analyzed. Results There were 42 cases in the control group and 39 cases in the experimental group. The awake PLMI, proportion of stage N1 sleep in total sleep time, proportion of stage N2 sleep in total sleep time, arousal index and PLMAI in experimental group were higher than those in control group (P<0.05) . However, the sleep efficiency and proportion of stage N3 sleep in total sleep time of experimental group were lower than those of control group (P<0.05) . There was no significant difference between two groups in sleep latency, AHI and REM stage sleep in total sleep time (P>0.05) . The results of Spearman rank correlation analysis showed that PLMS was positively correlated with awake PLMI, proportion of stage N2 sleep in total sleep time, sleep latency, arousal index, and PLMAI (rs values were 0.619, 0.250, 0.271, 0.312, 0.828, respectively; P values were <0.001, 0.024, 0.014, 0.005, <0.001) , which were negatively correlated with sleep efficiency (rs=-0.345, P=0.002) . Conclusion Stroke patients with PLMS have objective sleep disturbance and reduced sleep efficiency, and PLMS may be one of the signs of poor prognosis of stroke.

Keywords

• nocturnal myoclonus syndrome|periodic limb movements in sleep|periodic limb movement disorder|stroke|sleep structure