Posturography as an indicator of fatigue due to sleep deprivation

Fatigue is one of the main causes for accidents in transportation. This study was designed to assess the efficacy of a short objective posturographic test as an indicator of fatigue due to sleep deprivation.

To assess the efficiency of a short objective posturographic test as an indicator of fatigue due to sleep deprivation.

Postural control was measured using four-plate posturograhy with eyes open and eyes closed. Over a period of 26 h of sleep deprivation (from 08:00 to 10:00 the following day) 12 subjects were studied 10 times. The posturographic data were correlated with a subjective fatigue assessed by means of the Stanford Sleepiness Score.

Stability and sway intensity while eyes were closed showed a statistically significant circadian pattern with a peak at early morning hours and a recovery at 10:00 the following day. When eyes were open, only changes within the medium-low frequency band (0.1-0.05 Hz), believed to be linked with vestibular function, reached statistical significance. The Subjective Feeling Scale pattern was similar to the postural parameters, but with an absence of recovery at 10:00 the following day. Excluding this point, significant correlations were found between posturography with eyes closed and this scale.

Fatigue caused by sleep deprivation can be objectively assessed by a short, non-invasive, postural test. The vestibular function appears to be relatively more strongly affected by fatigue than the visual and somato-sensory sub-systems. Occlusion of vision appears to enhance the effect of fatigue on postural performance. Our results may imply that this test could be used as an efficient screening tool for detection of fatigue.