Periodic limb movements and heart rate changes.

Periodic limb movements (PLM) during sleep are believed to be under the control of the sympathetic nervous system and may cause interrupted sleep and daytime sleepiness. The present case highlights the close relationship between PLM and significant heart rate changes independent of the presence of arousals. Thus, in addition to the already known deleterious effect on sleep continuity, moderate-severe PLM may also affect cardiovascular health.