Leg movements and periodic leg movements during sleep in the development across childhood and adolescence from 1 to 18 years.

OBJECTIVE

Age specific reference values of leg movements (LMS) and periodic leg movements (PLMS) in sleep considering their true periodicity to evaluate sleep pathologies, especially possible childhood RLS or PLMD.

METHODS

In a prospective first night study of 52 healthy children/adolescents divided into six age groups from 1 to 18 years, polysomnographies were conducted and scored considering AASM rules. The frequency of LMS and PLMS were evaluated for NREM, REM, total sleep time (TST), including attention to time structure (inter-leg movement intervals, time distribution during the night) and periodicity of LMS.

RESULTS

LMS and PLMS decreased with increasing age (P < 0.05). Children and adolescents older than 10 years had a PLMS index less than 5/h TST, in younger children the PLMS index was higher; 34.7% of total LMS and PLMS were accompanied by an EEG-arousal without age dependence. Periodicity index was low (median 0.2 decreasing with age to 0.1). Inter-leg movement intervals showed a decreasing incidence of shorter intervals with age. The course of LMS during the night displayed a lack of clear structure of distribution.

CONCLUSIONS

To evaluate pediatric motoric sleep disturbances it is necessary to consider the age dependence of LMS/PLMS and their true periodicity.