Total sleep deprivation can increase vestibulo-ocular responses.

Area of Science:

• Neuroscience
• Vestibular System Research
• Sleep Science

Background:

• The impact of sleep deprivation on vestibular function remains unclear, with conflicting findings on postural balance and reflex changes.
• Previous research shows varied effects of sleep loss on vestibular reflexes, necessitating further investigation.

Purpose of the Study:

• To investigate the specific effects of sleep deprivation on the vestibulo-ocular reflex (VOR) using different rotational stimuli.
• To explore the potential role of cortical modulation in altered VOR responses following sleep deprivation.

Main Methods:

• Healthy subjects underwent horizontal eye movement recordings during earth-vertical axis rotation in darkness.
• Two conditions were tested: post-normal sleep and post-26-29 hours of sleep deprivation.
• Stimuli included a 60 degrees/s velocity step and sinusoidal rotation (0.2 Hz ±25 degrees/s).

Main Results:

• Sleep deprivation significantly increased VOR gain during the abrupt velocity step stimulus.
• No significant modification in VOR gain was observed during sinusoidal rotation after sleep deprivation.
• The difference in VOR response was attributed to the abrupt onset of the step stimulus versus continuous sinusoidal rotation.

Conclusions:

• Sleep deprivation differentially affects VOR responses depending on the nature of the vestibular stimulus.
• Abrupt vestibular stimuli, potentially engaging attentional networks involving the right temporoparietal cortex, show altered VOR gain after sleep deprivation.
• Findings suggest sleep deprivation-induced modulation of the right temporoparietal cortex influences VOR control during salient vestibular events.