Periodic leg movements during sleep and cerebral hemodynamic changes detected by NIRS.

OBJECTIVE: Periodic leg movements during sleep (PLMS) have been shown to be associated with changes in autonomic and hemispheric activities. Near infrared spectroscopy (NIRS) assesses hemodynamic changes linked to hemispheric/cortical activity. We applied NIRS to test whether cerebral hemodynamic alterations accompany PLMS.

METHODS: Three PLMS patients underwent nocturnal polysomnography coupled with cerebral NIRS. EEG correlates of PLMS were scored and NIRS data were analysed for the identification of correspondent hemodynamic changes.

RESULTS: PLMS were constantly associated with cerebral hemodynamic fluctuations that showed greater amplitude when associated to changes in EEG and were present also in absence of any visually detectable arousal or A phase in the EEG.

CONCLUSION: This is the first study documenting cerebral hemodynamic changes linked to PLMS.

SIGNIFICANCE: The clinical relevance of these observations remains to be determined.