Association entre les mouvements périodiques des jambes au cours du sommeil et l’intégrité de la matière blanche cérébrale
Periodic leg movements during sleep (PLMS) are repeated and stereotyped nocturnal motor activity characterized by dorsiflexion of the toes and ankle. Recent studies showed a temporal association between PLMS and activation of the sympathetic nervous system, characterized by a repeated increase in blood pressure and heart rate. The PLMS might be involved in the genesis of cardiovascular damage and favor the occurrence of cerebral injuries via an arteriolosclerosis process. In the present study, thirty-seven healthy subjects aged between 55 and 82 years old were recorded for one night of in-laboratory polysomnography and participated to a brain magnetic resonance imaging (MRI) session. Regression analysis were performed between the four PLMS severity variables, namely the PLMS index (PLMSI), the average time interval between PLMS, the PLMS mean duration and the number of PLMS associated with a micro-arousal (PLMS-MA) and neuroimaging variables (white matter hyperintensities, white matter structure through diffusion tensor imaging (DTI) and gray matter volume through voxel-based morphometry (VBM).  Our results showed that a higher PLMSI and PLMS-ME have been associated with reductions in white matter integrity in fronto-temporo-parietal regions. Also, reduction in grey matter volume was associated with a longer time interval between PLMS in the middle frontal gyrus. Associations observed in our sample suggest that PLMS may modify the microstructure of the brain and affect cerebrovascular integrity in middle-aged and older individuals.
Hypertension artérielle Periodic leg movement during sleep Sleep Arteriolosclerosis Neuroimaging Hypertension White matter hyperintensities Diffusion tensor imaging Voxel-based morphometry