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Presentazione fatta da V. Catania a Innovabiomed 2021.

The aim of this study was to define the time structure of leg movements during sleep occurring with an intermovement interval (onset-to-onset) shorter than 10 s in patients with restless legs syndrome and controls, and to compare it to the structure of movements with intervals of 10-90 s or >90 s. Polysomnographic recordings of 141 untreated patients and 68 age-matched normal controls were analysed. All movements were detected and classified into three categories, separated by intervals of 90 s. The number of movements included in each category was significantly higher in patients than in controls. The movements with an interval of >90 s occurred steadily during the night, whereas the hourly distribution of movements with intervals of 90 s. The time structure features of the three categories of movements considered in this study were found to be clearly different. This, together with previous observations on the differential effects of dopamine agonists on movements with different intervals, suggests that movements with intervals of 90 s are regulated by neurotransmitter mechanisms different from those modulating movements with an interval of 10-90 s.

The aim of this study was to evaluate the effects of a simple method of noise reduction before the calculation of the REM sleep atonia index (AI) on a large number of recordings from different normal controls and patient groups.Eighty-nine subjects were included: 25 young controls, 10 aged controls, 31 untreated patients with idiopathic REM sleep behavior disorder (iRBD), 8 treated patients with iRBD, 10 patients with multiple system atrophy (MSA) and 5 patients with obstructive sleep apnea syndrome (OSAS). The average amplitude of the rectified submentalis muscle EMG signal was then obtained for all 1-s mini epochs of REM sleep. The new correction method was implemented by subtracting from each mini epoch the minimum value found in a moving window including the 60 mini epochs surrounding it.Two arbitrary thresholds were established at AI0.8 and 0.8AI0.9; all young controls presented AI0.9; this was not true for aged controls, 3 of whom presented 0.8AI0.9 but none had AI0.8; on the contrary 74.4% of all iRBD showed AI0.9, with 38.5% of the whole group having AI0.8 and only 25.6% with AI0.9. All MSA patients showed AI0.8.After the introduction of this new method for noise reduction, REM sleep AI index values lower than 0.8 were strongly indicative of altered (reduced) chin EMG atonia during REM sleep; values of AI between 0.8 and 0.9 indicated a less evident involvement of atonia, and values above 0.9 characterized the majority of normal recordings.

The objective of this study was to describe in detail the heart rate changes accompanying short-interval leg movements during sleep, periodic leg movements during sleep, and isolated leg movements during sleep in children and adolescents with restless legs syndrome, and to compare them with the same findings in adults with restless legs syndrome. We analysed time series of R-R intervals synchronized to the onset of short-interval leg movements during sleep, periodic leg movements during sleep or isolated leg movements during sleep that entailed an arousal during non-rapid-eye-movement sleep. We assessed cardiac activation based on the heart rate changes with respect to baseline during non-rapid-eye-movement sleep without leg movements. All types of leg movements recorded during sleep were accompanied by important heart rate changes also in children, with an overall impact similar to that observed in adults. In all age groups, heart rate changes accompanying short-interval leg movements during sleep were constituted by a tachycardia, without a subsequent relative bradycardia, that was instead evident for periodic leg movements during sleep and isolated leg movements during sleep. Moreover, an age-related decline of the relative bradycardia following the heart rate increase, in association with periodic leg movements during sleep and isolated leg movements during sleep, was observed. Our findings show that important heart rate changes accompany all leg movements during sleep at all ages in restless legs syndrome, with significant age-related differences. This information represents an important contribution to the ongoing scientific debate on the possibility and opportunity to treat periodic leg movements during sleep.