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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

Body temperature rhythms and phase.(A) Circadian rhythm of gastrointestinal temperature: Mean values (-) and SD (grey line) recorded every 60 s is shown for Patients (upper panel) and Controls (lower panel). The dashed blue lines represent modeling using the COSINOR method. Dark frame represents the sleeping period in the laboratory. (B) Individual acrophases of temperature in Controls (◇) and Patients (●). The 6th control participant was removed from the analyses. The F-test revealed a larger variability (p<0.05) in the time of acrophase in Patients compared to Controls.
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pone.0155067.g003: Body temperature rhythms and phase.(A) Circadian rhythm of gastrointestinal temperature: Mean values (-) and SD (grey line) recorded every 60 s is shown for Patients (upper panel) and Controls (lower panel). The dashed blue lines represent modeling using the COSINOR method. Dark frame represents the sleeping period in the laboratory. (B) Individual acrophases of temperature in Controls (◇) and Patients (●). The 6th control participant was removed from the analyses. The F-test revealed a larger variability (p<0.05) in the time of acrophase in Patients compared to Controls.

Mentions: Thus both patients and control participants displayed thus a diurnal temperature rhythm in accordance with the literature, with higher values in the afternoon. When COSINOR analysis was applied to all temperature data, the estimates confirmed the visual impression (see Fig 2): both curves did not differ strongly, but the acrophase was subject to a group effect (see Table 6). The estimated acrophase of the control group had a value of 17.49 (i.e., 5:29PM), whereas the acrophase of the patient group was significantly advanced by 1.22 (i.e., 1 h 13 min), in patients (4:16 PM). The comparison of individual circadian parameters revealed a larger variability of observed acrophase (Fig 3) in the patient group compared to the control group, with individual acrophases ranging from 2:24 PM to 9:25 PM (F test; p<0.05).


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)

Body temperature rhythms and phase.(A) Circadian rhythm of gastrointestinal temperature: Mean values (-) and SD (grey line) recorded every 60 s is shown for Patients (upper panel) and Controls (lower panel). The dashed blue lines represent modeling using the COSINOR method. Dark frame represents the sleeping period in the laboratory. (B) Individual acrophases of temperature in Controls (◇) and Patients (●). The 6th control participant was removed from the analyses. The F-test revealed a larger variability (p<0.05) in the time of acrophase in Patients compared to Controls.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0155067.g003: Body temperature rhythms and phase.(A) Circadian rhythm of gastrointestinal temperature: Mean values (-) and SD (grey line) recorded every 60 s is shown for Patients (upper panel) and Controls (lower panel). The dashed blue lines represent modeling using the COSINOR method. Dark frame represents the sleeping period in the laboratory. (B) Individual acrophases of temperature in Controls (◇) and Patients (●). The 6th control participant was removed from the analyses. The F-test revealed a larger variability (p<0.05) in the time of acrophase in Patients compared to Controls.
Mentions: Thus both patients and control participants displayed thus a diurnal temperature rhythm in accordance with the literature, with higher values in the afternoon. When COSINOR analysis was applied to all temperature data, the estimates confirmed the visual impression (see Fig 2): both curves did not differ strongly, but the acrophase was subject to a group effect (see Table 6). The estimated acrophase of the control group had a value of 17.49 (i.e., 5:29PM), whereas the acrophase of the patient group was significantly advanced by 1.22 (i.e., 1 h 13 min), in patients (4:16 PM). The comparison of individual circadian parameters revealed a larger variability of observed acrophase (Fig 3) in the patient group compared to the control group, with individual acrophases ranging from 2:24 PM to 9:25 PM (F test; p<0.05).

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