How (and Why) Traumatic Brain Injury Harms Sleep
As many as 70 percent of individuals suffer from sleep disturbances after a traumatic brain injury (TBI). Although many will experience a complete recovery, disrupted sleep can often go untreated — and this can impede recovery and reduce quality of life. As a result, researchers undertook a meta-analysis of studies in an attempt to identify the characteristics of sleep disturbances associated with TBI. Their results were published in the Journal of Clinical Sleep Medicine in 2016.
Researchers only analyzed studies that were published in English and compared sleep function in adults with TBI with a control group. Studies were only included in the analysis if all participants in TBI groups were over the age of 16, had sustained a TBI or head injury that led to a loss of consciousness or posttraumatic amnesia, and were not in hospital when the study took place. Participants in control groups had to be described as either healthy or without a history of TBI, neurological illness, or sleep disturbances.
Sixteen studies were included in the analysis and involved 637 individuals with TBI and 567 individuals without TBI who served as controls. The average age of participants with TBI was 32 years and 71 percent were men. The average of age of those in the control groups was 32 years and 66 percent were men.
Of the included studies, 10 used polysomnography to measure sleep disturbances, two used actigraphy, two only measured how long it took participants to fall asleep (multiple sleep latency test), and two only measured how long participants were able to stay awake (maintenance of wakefulness test).
Objective sleep disturbances after traumatic brain injury
Researchers found that, compared to controls, those with TBI:
Had poorer sleep efficiency
Took longer to fall asleep
Got less sleep
Spent more time awake during the night
Spent less time in REM sleep
Subjective sleep disturbances after traumatic brain injury
When measuring sleep quality using questionnaires such as the Epworth Sleepiness Scale and Pittsburgh Sleep Quality Index, compared to controls, those with TBI reported:
Poorer sleep quality
Taking longer to fall asleep
Shorter sleep duration
Poorer sleep efficiency
More daytime dysfunction
More sleep disturbance
More sleep medication
The sleep disorders associated with traumatic brain injury
Researchers pointed to previous research that identified the following sleep disorders as being common in those who have sustained a TBI:
Researchers found that individuals with mild TBI and moderate to severe TBI both experienced less overall sleep, poorer sleep efficiency, and spent more time awake during the night compared to controls.
Interestingly, those with mild TBI tended to take longer to fall asleep and spent less time in REM sleep compared to those with moderate to severe TBI. Researchers suggested this may be because individuals with mild TBI tend to retain more self-awareness.
Why is TBI associated with sleep disturbances?
The authors of the study pointed out that TBI is often associated with an increased need for sleep, which may explain the complaints of sleepiness from those with head injuries.
They also stated that brain injuries can affect hypocretin production, which can lead to daytime sleepiness and even narcolepsy. Such injuries can also reduce melatonin secretion at night which can lead to reduced REM sleep.
Researchers also suggested that the location of a head injury may be more important than the overall severity of the injury when it comes to the effect on sleep; damage to regions associated with sleep regulation can lead to more sleep disturbances.
How to treat sleep disturbances caused by TBI
The authors of the study pointed out that few sleep treatments have proven effective in cases of TBI. Although benzodiazepines can provide short-term benefits, they are not recommended for long term use. With that being said, a recent study found cognitive behavioral therapy for insomnia led to significant sleep improvements in those who had sustained a TBI.
A few words of caution
It’s important to point out that since this review couldn’t assess sleep quality before the occurrence of the TBI it could not imply causality between the TBI event and any consequent sleep disturbances. Additionally, the common use of medication as a result of a TBI may also contribute to the sleep issues experienced by those with a head injury.
Still, the authors of this study believed the association was strong enough to suggest that physicians monitor and address sleep disturbances in treatment programs following traumatic brain injury.