Morning/Evening Differences in Somatosensory Inputs for Postural Control

Abstract

The underlying processes responsible for the differences between morning and afternoon measurements of postural control have not yet been clearly identified. This study was conducted to specify the role played by vestibular, visual, and somatosensory inputs in postural balance and their link with the diurnal fluctuations of body temperature and vigilance level. Nineteen healthy male subjects (mean age: 20.5 ± 1.3 years) participated in test sessions at 6:00 a.m. and 6:00 p.m. after a normal night's sleep. Temperature was measured before the subjects completed a sign cancellation test and a postural control evaluation with eyes both open and closed. Our results confirmed that postural control improved throughout the day according to the circadian rhythm of body temperature and sleepiness/vigilance. The path length as a function of surface ratio increased between 6:00 a.m. and 6:00 p.m. This is due to a decrease in the centre-of-pressure surface area, which is associated with an increase in path length. Romberg's index did not change throughout the day; however, the spectral analysis (fast Fourier transform) of the centre-of-pressure excursions (in anteroposterior and mediolateral directions) indicated that diurnal fluctuations in postural control may occur via changes in the different processes responsible for readjustment via muscle contractions.

Integrating postural and vestibular dimensions to depict impairment in moderate‐to‐severe obstructive sleep apnea syndrome patients

“…As noted previously (Beraneck and Idoux, 2012), the integration of information from the visual, vestibular and somatosensory receptors and motor coordination are processes known to require attention and vigilance (Bougard and Davenne, 2014;Fabbri et al, 2006;Gomez et al, 2008), especially when information from any of the sensory systems is not reliable (Redfern et al, 2001a). Hence, OSAS patients' chronic sleep restriction and related attention and vigilance decrease may lead to slower or inappropriate sensory integration (Beraneck and Idoux, 2012;Bougard and Davenne, 2014).…”

“…Hence, OSAS patients' chronic sleep restriction and related attention and vigilance decrease may lead to slower or inappropriate sensory integration (Beraneck and Idoux, 2012;Bougard and Davenne, 2014). In turn, this process could also result in affecting the ability underlying the most efficient adjustments of movements involved in postural sway regulation (Beraneck and Idoux, 2012;Bougard and Davenne, 2014).…”

“…All this sensorial information is processed in the cerebellum, enabling the centre of gravity to be supported and maintained by postural muscle contractions (Nashner, 1985). From this perspective, through the use of static posturography (and related implementations) (Bougard and Davenne, 2014;Nashner, 1985), evaluation of the possible contributions of vestibular, visual and somatosensory inputs to postural control throughout the day and its relationship with circadian rhythm is of great interest. In particular, considering time-of-day effects, the decrease during the day within the low-frequency band of postural sway spectrum (Nagy et al, 2004), confirms that the visuo-vestibular system is highly affected by circadian rhythms and that the sensitivity of visual (De Gennaro et al, 2001) and especially of vestibular (Wolf et al, 1990) systems may improve throughout the day (Bougard and Davenne, 2014).…”

“…Although there is still debate on this approach, and the results of previous clinical otoneurological assessments in OSAS groups were proved to be within a normality range (Kayabasi et al, 2015;Nagy et al, 2007), studies based on sleep deprivation paradigms (which modify the level of sleepiness/vigilance) have reported that the vestibular system would be the sensory input most affected by an increase in the length of awake time (Avni et al, 2006;Bougard and Davenne, 2014;Liu et al, 2001;Morad et al, 2007). Moreover, it has been shown that sleep deprivation in humans may induce an alteration in the posterior parietal cortex (Drummond and Brown, 2001), which plays a crucial role in processing vestibular information in relation to space representation and the regulating vestibulo-ocular reflex (VOR) (Quarck et al, 2006).…”

Time-of-Day Effects on Dynamic Postural Control

“…1 I．はじめに 高齢者における転倒は，日中のみでなく夜間から早朝 にも多く発生する 1,2) ．その原因には不眠症 3) ，起立性 低血圧 4) ，抑鬱 5) などが考えられているが，平衡機能自 体が概日リズムや覚醒状態に依存するという報告も散見 される [6][7][8][9][10][11][12][13][14] ．26 時間の睡眠遮断における経時的な重心…”