Article

Standing postural stability relies on input from visual, vestibular,
proprioceptive and mechanoreceptive sensors. When the information from any of
these sensors is unavailable or disrupted, the central nervous system maintains
postural stability by relying more on the contribution from the reliable sensors,
termed sensory re-weighting. Alcohol intoxication is known to affect the
integrity of the vestibular and visual systems. The aim was to assess how
mechanoreceptive sensory information contributed to postural stability at 0.00%
(i.e. sober), 0.06% and 0.10% blood alcohol concentration (BAC) in 25 healthy
subjects (mean age 25.1 years). The subjects were assessed with eyes closed and
eyes open under quiet standing and while standing was perturbed by repeated,
random-length, vibratory stimulation of the calf muscles. Plantar cutaneous
mechanoreceptive sensation was assessed for both receptor types: slowly adapting
(tactile sensitivity) and rapidly adapting (vibration perception). The
correlation between recorded torque variance and the sensation from both
mechanoreceptor types was calculated. The recorded stability during alcohol
intoxication was significantly influenced by both the tactile sensation and
vibration perception of the subjects. Moreover, the study revealed a fluctuating
association between the subjects' vibration perception and torque variance during
balance perturbations, which was significantly influenced by the level of alcohol
intoxication, vision and adaptation. Hence, one's ability to handle balance
perturbations under the influence of alcohol is strongly dependent on accurate
mechanoreceptive sensation and efficient sensory re-weighting.
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Langue : ANGLAIS