Nav: Home

Level of unconsciousness in brain damaged patients related to body temperature

April 20, 2017

Circadian rhythms may play a crucial role in the recovery of consciousness of patients with severe brain injuries, a study published in Neurology.

In the first ever study of its kind, researchers from the University of Surrey and the University of Salzburg, Austria, examined circadian body temperature variations of 18 patients suffering from severe brain injuries and the potential link to consciousness. Circadian rhythms are an approximate 24-hour cycle governed by the body's internal clock and they determine a number of physiological processes in the body including core body temperature, which fluctuates throughout the day.

To assess the body temperature of patients, researchers used four external skin sensors to monitor the circadian rhythm, which was found to range between 23.5 hours and 26.3 hours. The level of consciousness of each patient was evaluated through the Coma Recovery Scale-Revised, which among others measures responsiveness to sound or a patient's ability to spontaneously open eyes without or only with stimulation by the examiner.

Researchers discovered that patients who scored better on the Coma Recovery Scale-Revised, especially, those patients with a stronger arousal had body temperature patterns that were more closely aligned with a healthy 24-hour rhythm. This finding demonstrates a newly discovered relationship between circadian body temperature variation and the level of consciousness of a patient with severe brain damage. This finding suggests that patient's consciousness levels should be assessed during time windows when their circadian rhythm predicts them to be more responsive.

The effects of bright light stimulation on patients with severe brain injuries was also investigated during this study. To measure its effectiveness, eight patients received bright light stimulation, three times per day for one hour over the course of one week. After one week, improvements were found in the level of consciousness of two patients, whose condition improved from vegetative state/unresponsive wakefulness to a minimally conscious state. Interestingly, in these two patients, a shift in their circadian body temperature, closer to a healthy 24-hour rhythm was also recorded.

Co-investigator of the paper Dr Nayantara Santhi from the Surrey Sleep Research Centre, University of Surrey, said:

"Prior to our study little was known about the circadian rhythms of patients with brain injuries. What we have learnt is that the circadian body temperature holds vital clues to the state of consciousness of patients which could potentially enable doctors to tailor medical treatment more effectively.

"Circadian rhythms hold the secret to the workings of the body and we will be looking further into this in future research."

Lead author of the paper Dr Christine Blume, from the University of Salzburg, said:

"Our study suggests that the closer the body temperature patterns of a severely brain injured person are to those of a healthy person's circadian rhythm, the better they scored on tests of recovery from coma, especially when looking at arousal, which is necessary for consciousness.

"Circadian variations is something doctors should keep in mind when diagnosing patients, especially the time of the day when patients are tested could be crucial. Also, it may be important to create an environment that mimics the normal light-dark cycle to support a healthy circadian rhythm."
-end-


University of Surrey

Related Circadian Rhythms Articles:

Youth with abnormal heart rhythms more likely to have ADHD, anxiety, depression
Children and adolescents with abnormal heart rhythms are more likely to have ADHD, anxiety and depression compared to their counterparts with either other select chronic childhood illnesses or no chronic medical conditions, according to new research.
What drives circadian rhythms at the poles?
Circadian clocks coordinate the organism to the alternating cycles of day and night.
Chronobiology: Sleep and synaptic rhythms
Chronobiologists at Ludwig-Maximilians-Universitaet (LMU) in Munich, Germany, show in two articles in the journal Science how critical the sleep-wake cycle is for protein and phosphorylation dynamics in synapses to ultimately regulate its activity.
Mathematical model explores daily rhythms in pain sensitivity
A new computational model successfully predicts how daily pain sensitivity rhythms affect pain processing, both in healthy adults and in people with neuropathic pain.
Chronic disruptions to circadian rhythms promote tumor growth, reduce efficacy of therapy
In a study published today in the journal PLOS Biology, researchers at Penn Medicine show circadian disruptions trigger an increase in cell proliferation that, ultimately, shifts the cell-cycle balance and stimulates the growth of tumors in mice.
BPA exposure during pregnancy can alter circadian rhythms
Exposure to the widely used chemical bisphenol A (BPA) during pregnancy, even at levels lower than the regulated 'safe' human exposure level, can lead to changes in circadian rhythms, according to a mice study to be presented Monday at ENDO 2019, the Endocrine Society's annual meeting in New Orleans, La.
New role for brain's support cells in controlling circadian rhythms
An Medical Research Council funded study published today in the journal Science, has found that astrocytes, previously thought of as just supporting neurons in regulating circadian rhythms, can actually lead the tempo of the body's internal clock and have been shown for the first time to be able to control patterns of daily behaviour in mammals.
Disrupted circadian rhythms may drive anxiety and exacerbate brain disorders
Sleep disruptions are associated with many brain disorders, including anxiety, dementias, and traumatic brain injury.
VIP neurons shift daily rhythms
Neurons in the brain's master clock that adjust their activity in response to light have a key role in the resetting of an animal's daily cycle, finds a study of male and female mice published in JNeurosci.
The rhythms of the night?
New research published in The Journal of Physiology has illuminated the effects of night-time light exposure on internal body clock processes.
More Circadian Rhythms News and Circadian Rhythms Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Accessing Better Health
Essential health care is a right, not a privilege ... or is it? This hour, TED speakers explore how we can give everyone access to a healthier way of life, despite who you are or where you live. Guests include physician Raj Panjabi, former NYC health commissioner Mary Bassett, researcher Michael Hendryx, and neuroscientist Rachel Wurzman.
Now Playing: Science for the People

#544 Prosperity Without Growth
The societies we live in are organised around growth, objects, and driving forward a constantly expanding economy as benchmarks of success and prosperity. But this growing consumption at all costs is at odds with our understanding of what our planet can support. How do we lower the environmental impact of economic activity? How do we redefine success and prosperity separate from GDP, which politicians and governments have focused on for decades? We speak with ecological economist Tim Jackson, Professor of Sustainable Development at the University of Surrey, Director of the Centre for the Understanding of Sustainable Propserity, and author of...
Now Playing: Radiolab

An Announcement from Radiolab