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Exploration of Circadian Rhythms in Patients with Bilateral Vestibular Loss.

Martin T, Moussay S, Bulla I, Bulla J, Toupet M, Etard O, Denise P, Davenne D, Coquerel A, Quarck G - PLoS ONE (2016)

Bottom Line: Nine patients presenting a total idiopathic BVL and 8 healthy participants were compared.Sleep efficiency was reduced in patients compared to control participants.Salivary cortisol levels were higher in patients compared to healthy people at any time of day.

View Article: PubMed Central - PubMed

Affiliation: UNICAEN, COMETE, 14032 Caen, France.

ABSTRACT

Background: New insights have expanded the influence of the vestibular system to the regulation of circadian rhythmicity. Indeed, hypergravity or bilateral vestibular loss (BVL) in rodents causes a disruption in their daily rhythmicity for several days. The vestibular system thus influences hypothalamic regulation of circadian rhythms on Earth, which raises the question of whether daily rhythms might be altered due to vestibular pathology in humans. The aim of this study was to evaluate human circadian rhythmicity in people presenting a total bilateral vestibular loss (BVL) in comparison with control participants.

Methodology and principal findings: Nine patients presenting a total idiopathic BVL and 8 healthy participants were compared. Their rest-activity cycle was recorded by actigraphy at home over 2 weeks. The daily rhythm of temperature was continuously recorded using a telemetric device and salivary cortisol was recorded every 3 hours from 6:00AM to 9:00PM over 24 hours. BVL patients displayed a similar rest activity cycle during the day to control participants but had higher nocturnal actigraphy, mainly during weekdays. Sleep efficiency was reduced in patients compared to control participants. Patients had a marked temperature rhythm but with a significant phase advance (73 min) and a higher variability of the acrophase (from 2:24 PM to 9:25 PM) with no correlation to rest-activity cycle, contrary to healthy participants. Salivary cortisol levels were higher in patients compared to healthy people at any time of day.

Conclusion: We observed a marked circadian rhythmicity of temperature in patients with BVL, probably due to the influence of the light dark cycle. However, the lack of synchronization between the temperature and rest-activity cycle supports the hypothesis that the vestibular inputs are salient input to the circadian clock that enhance the stabilization and precision of both external and internal entrainment.

No MeSH data available.


Related in: MedlinePlus

Salivary cortisol levels.Salivary cortisol profiles are shown for Patients (black) and Controls (grey). * indicates a significant effect of time of day. § indicates a significant difference between groups.
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pone.0155067.g001: Salivary cortisol levels.Salivary cortisol profiles are shown for Patients (black) and Controls (grey). * indicates a significant effect of time of day. § indicates a significant difference between groups.

Mentions: On average, both groups displayed similar profiles of salivary cortisol, but the mean cortisol level was significantly higher in the patient group (3.49 ± 1.85 pg/mL compared to 2.68 ± 1.55 pg/mL;p = 0.02) and the patient group presented a higher cortisol value than the control group at all times of day (p = 0.001; Table 4). Higher values were recorded during the 6:00 AM session test (5.95 ± 2.17 pg/mL for patients; 5.17± 1.22 pg/mL for controls; p<0.001) compared to other session tests, and lower values were reported during the 12:00, 3:00, 6:00 and 9:00 PM session tests (Fig 1).


Exploration of Circadian Rhythms in Patients with Bilateral Vestibular Loss.

Martin T, Moussay S, Bulla I, Bulla J, Toupet M, Etard O, Denise P, Davenne D, Coquerel A, Quarck G - PLoS ONE (2016)

Salivary cortisol levels.Salivary cortisol profiles are shown for Patients (black) and Controls (grey). * indicates a significant effect of time of day. § indicates a significant difference between groups.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4920359&req=5

pone.0155067.g001: Salivary cortisol levels.Salivary cortisol profiles are shown for Patients (black) and Controls (grey). * indicates a significant effect of time of day. § indicates a significant difference between groups.
Mentions: On average, both groups displayed similar profiles of salivary cortisol, but the mean cortisol level was significantly higher in the patient group (3.49 ± 1.85 pg/mL compared to 2.68 ± 1.55 pg/mL;p = 0.02) and the patient group presented a higher cortisol value than the control group at all times of day (p = 0.001; Table 4). Higher values were recorded during the 6:00 AM session test (5.95 ± 2.17 pg/mL for patients; 5.17± 1.22 pg/mL for controls; p<0.001) compared to other session tests, and lower values were reported during the 12:00, 3:00, 6:00 and 9:00 PM session tests (Fig 1).

Bottom Line: Nine patients presenting a total idiopathic BVL and 8 healthy participants were compared.Sleep efficiency was reduced in patients compared to control participants.Salivary cortisol levels were higher in patients compared to healthy people at any time of day.

View Article: PubMed Central - PubMed

Affiliation: UNICAEN, COMETE, 14032 Caen, France.

ABSTRACT

Background: New insights have expanded the influence of the vestibular system to the regulation of circadian rhythmicity. Indeed, hypergravity or bilateral vestibular loss (BVL) in rodents causes a disruption in their daily rhythmicity for several days. The vestibular system thus influences hypothalamic regulation of circadian rhythms on Earth, which raises the question of whether daily rhythms might be altered due to vestibular pathology in humans. The aim of this study was to evaluate human circadian rhythmicity in people presenting a total bilateral vestibular loss (BVL) in comparison with control participants.

Methodology and principal findings: Nine patients presenting a total idiopathic BVL and 8 healthy participants were compared. Their rest-activity cycle was recorded by actigraphy at home over 2 weeks. The daily rhythm of temperature was continuously recorded using a telemetric device and salivary cortisol was recorded every 3 hours from 6:00AM to 9:00PM over 24 hours. BVL patients displayed a similar rest activity cycle during the day to control participants but had higher nocturnal actigraphy, mainly during weekdays. Sleep efficiency was reduced in patients compared to control participants. Patients had a marked temperature rhythm but with a significant phase advance (73 min) and a higher variability of the acrophase (from 2:24 PM to 9:25 PM) with no correlation to rest-activity cycle, contrary to healthy participants. Salivary cortisol levels were higher in patients compared to healthy people at any time of day.

Conclusion: We observed a marked circadian rhythmicity of temperature in patients with BVL, probably due to the influence of the light dark cycle. However, the lack of synchronization between the temperature and rest-activity cycle supports the hypothesis that the vestibular inputs are salient input to the circadian clock that enhance the stabilization and precision of both external and internal entrainment.

No MeSH data available.


Related in: MedlinePlus