PERIODIC LEG MOVEMENTS DURING SLEEP AND SLEEP DISTURBANCES IN ELDERS

Background. Periodic limb movements in sleep (PLMS) are an increasingl y pervasive disturbance for aging adults. The aims of this experiment were: (a) to describe the index of periodic limb movements in sleep (m yoclonus index [MI] in elderly subjects with complaints of poor sleep or depression (N = 22; 68 +/- 5.5 SD years); and (b) to correlate MI w ith sleep history, depression scores, and objective and subjective ind ices of sleep. Method. Sleep and leg movements were assessed for 5 con secutive nights. Between-subjects, nonparametric correlations were exa mined between mean MI and sleep history, depression scores, and object ive and subjective sleep characteristics. Associations among within-su bject night-to-night variabilities of MI, objective, and subjective va riables were examined with repeated measures ANCOVA, entering MI as a covariate. Results. A remarkably high level of MI was found (median 25 .8 events per hour; 86% of subjects > 5). Nevertheless, no association s were found between MI and sleep disturbance measures. Conclusion. Th ese results extend previous reports that PLMS are remarkably persuasiv e in elderly volunteers and support other reports questioning whether there is a distinct PLMS syndrome.