traumatic brain injury (TBI), people experience major sleep problems.
- The thinking abilities and
level of consciousness go hand-in-hand with improvements in sleep patterns.
people did not attain a certain level of consciousness to keep them aware and
awake, they did not generate good sleep-wake cycle.
sleep cycles improved, people gave appropriate response to stimuli and their
ability to recall the tasks improved.
Recovering from a traumatic brain injury
improvement in sleep patterns go hand-in-hand. Traumatic brain
injury (TBI), leads to major sleep problems
including changes in sleep-wake cycle
A new study by a
research team from the University of Montréal suggests that recovering from these two conditions occurs in parallel.
‘Recovery after a traumatic brain injury can be assessed by monitoring the patient’s sleep-wake cycle.’
"These results suggest that
monitoring a person's sleep-wake cycle may be a useful tool for assessing their
recovery after TBI," said study author Nadia Gosselin, PhD, of the
University of Montréal in Québec, Canada. "We found that when someone
sustained a brain injury and had not recovered a certain level of consciousness
to keep them awake and aware of their surroundings, they were not able to
generate a good sleep-wake cycle. But as they recovered, their quality of sleep
Traumatic Brain Injury
Head injury or traumatic brain
injury (TBI) occurs due to sudden trauma to the head or brain, resulting in
brain damage. It is the leading cause for disability among children and young
Although traumatic head injury can
affect people of all ages, young adults between the age of 15 and 24 years and
those above 75 years face an increased risk of head injury.
Every year, approximately 1.4
million people experience a head injury, out of which about 50,000 individuals
die. Annual hospital admissions due to TBI are more than 230,000 people.
TBI is usually caused when an external
force is sufficient enough to cause movement of the brain within the skull or
causes the skull to break, thereby inducing a direct injury to the brain.
A majority of the head injuries,
about 50%, are as a result of road traffic accidents involving motorbikes,
automobiles and bicycles.
In persons above the age of 75
years, falls account for a major proportion of head injuries.
Other less common causes of TBI
include violence, such as gunshots, firearm assaults, and child abuse, which
accounts for approximately 20%. Sports injuries are responsible for 3% of head
A good sleep-wake cycle is
said to be achieved when a person is alert and active
during the day and gets uninterrupted sleep at
It is also known as circadian rhythm
which is a biological process that
follows an internal cycle of approximately 24 hours.
Light will stimulate the production
of cortisol, serotonin, other hormones and neurotransmitters that gets a person
up and about and causes the blood pressure and body temperature to rise.
At sunset, the body receives another
of nature's cues and responds to dusk and ultimately the night's darkness. As
the sun goes down, the body will produce and secrete the hormone melatonin, and
blood pressure will drop as the body prepares for and eventually falls off to
This rhythm controls the timing,
quantity and quality of the hormones and neurotransmitters the body produces
and eventually secretes.
Testing the Link
To test their hypothesis, research team recruited 30 people, aged 17 to 58 years, who
suffered from moderate to severe TBI. Most of the patients
were admitted to the hospital in a coma stage
and all y received intensive care initially.
Twenty people suffered from motor vehicle accident related TBI. Seven people suffered
from fall related TBI. Two people had recreational or sports
injuries and one person had received a
blow to the head.
They were hospitalized for an
average of 45 days and the study began on an average of 21 days into a person's stay.
Patients wore an activity monitor
on their wrist for sleep recording and they were monitored
daily for an average of 11 days for level of consciousness and cognitive
functions like thinking, using a Rancho Los Amigos (RAL)
, that ranges from levels 1 to 8.
In level 1 of the scale, the
patient appears asleep and does not respond to external stimuli and in level 8,
patient is awake, oriented and responds to external stimulus.
Findings of the
Findings showed a linear
relationship between improvement in the level of consciousness and thinking
abilities and different measures of quality of sleep.
One measure of sleep was the
daytime activity ratio that is the percentage of activity that occurs during
the day. The findings showed that activity occurs throughout
the day and night immediately following
reached an acceptable sleep-wake cycle, with a daytime activity ratio of at
least 80%, at the same point when they
emerged from a minimally conscious state.
At a score of 5 on
the Rancho Los Amigos scale, people still had inadequate sleep.
At this level, they were confused and gave inappropriate responses to stimuli but were able to follow simple commands.
When a score of 6 is attained on
the Rancho Los Amigos scale, sleep-wake cycles reached
adequate levels At this stage, though people depended
on external stimuli, they gave appropriate responses. They were able to
remember re-learned tasks, but could
not remember new tasks.
When adjusted for
the amount of time that had passed since the injury and the amount of
medications received by the patients, results did not vary.
"It's possible that there are
common underlying brain mechanisms involved in both recovery from TBI and
improvement in sleep," said Gosselin. "Still, more study needs to be
done and future research may want to examine how hospital lighting and noise
also affect quality of sleep for those with TBI."
The study is published in Neurology
, the medical journal of the American Academy of Neurology.
- Circadian Rhythm Sleep Disorders -
- Head injury / Brain Injury - (http://www.medindia.net/patients/patientinfo/headinjury_causes.htm)
Nadia Gosselin et al.
Parallel recovery of consciousness and sleep in acute traumatic brain injury. Neurology;