Abstract
Background: Maintaining postural control requires the continuous integration of different
peripheral inputs that may be altered by sleepiness. The objective of this study was to assess
the effects of 24 hours sleep deprivation on postural stability.
Methods: healthy subjects underwent 24 hours supervised sleep deprivation after a week of
stable sleep schedule. Stability was assessed using a posturographic platform allowing to
determine the center of foot pressure (CoP) oscillations in mediolateral (ML) and
anteroposterior (AP) axis and thereby total XY displacement, the surface area and the mean
speed of CoP displacement. Measurements were performed in the morning before sleep
deprivation and every two hours during the night. Vigilance and fatigue were evaluated at the
same intervals using the Psychomotor Vigilance Test (PVT), and the Karolinska sleepiness
scale (KSS).
Results: 30 volunteers (7 men and 23 women, aged 22±2 yo, BMI 18.5-25kg/m2) were
included in the study. When comparing pre-and post-sleep deprivation morning stability
parameters, there was significant deterioration in the majority of the postural variables: CoP
area (P<0.05), AP (P<0.01) and total displacement (P<0.05) as well as in some PVT’s
variables: reaction time (P<0.001), lapses (P<0.05) and in subjective sleepiness (P<0.001).
During the sleep deprivation night, there was a progressive and parallel deterioration of the
stability and vigilance parameters that reached its maxima at 4 a.m., followed by a mild
improvement at 6 a.m.
Conclusions: Postural control is significantly altered by 24 hours sleep deprivation and seems
to fluctuate in a similar pattern as vigilance and subjective sleepiness.