Have you ever suffered from a traumatic brain injury? It doesn’t have to be extraordinarily severe – maybe perhaps just a concussion? Believe it or not, there is a strong link between traumatic brain injury (TBI) and sleep. Following a TBI, people report feeling like they have poorer sleep (e.g., more awakenings). Additionally, people seem to need more sleep, perhaps because sleep is helping the brain heal. But what about sleep apnea? Might there be an increase or even decrease in sleep apnea incidence following a TBI?
An investigation using a large number of post-combat soldiers asked this very question. This study, based at Walter Reed (a hospital for veterans), included soldiers who had experienced mild, moderate, or severe TBI. Importantly, although these were soldiers, most experienced only mild TBIs, which are similar to run-of-the-mill concussions. Participants all underwent a clinical examination in which they were asked about their sleep disturbances. They also underwent an overnight sleep study so that they could be screened for sleep apnea presence and severity.
Results showed a very high percentage of TBI sufferers had insomnia (55%) and sleep apnea (44%). Interestingly, insomnia was more common in those who had suffered from TBI following a blast injury, and sleep apnea was more common in those who suffered from a blunt head trauma.
Insomnia is perhaps not surprising in this population, given that many were diagnosed with PTSD and/or depression and many were taking medications for psychological disorders. The presence of sleep apnea, surprisingly, was very, very high in this sample. But what is missing? If you said a control group, you are correct. Perhaps individuals coming home from a war zone are much more likely to suffer from insomnia than normal individuals (even if they have not suffered from a TBI), and insomnia rate may be comparable to those seen here. Being at war could increase the risk for sleep apnea. Although this is unlikely, only by using a control group could a true assessment of sleep disorders after TBI be made.
Source: Collen, J., Orr, N., Lettieri, C. J., Carter, K., & Holley, A. B. (2012). Sleep disturbances among soldiers with combat-related traumatic brain injury. CHEST Journal, 142(3), 622-630.