Sleep disorders tend to be classified as insomnia, excessive sleep, or excessive daytime sleepiness (EDS) (Elovic et al. 2005; Ouellet et al. 2015). It is believed that, in individuals with ABI, sleep complaints correlate with higher Glasgow Coma Scores (GCS >7) at time of injury, better immediate memory, pre-ABI presence of fatigue, a history of substance abuse, older age and female gender (Thaxton & Patel 2007). There are few studies that have investigated sleep disorders and their effects on rehabilitation post ABI (Baumann et al. 2007; Clinchot et al. 1998). It has been suggested that those who sustain a more severe TBI may underreport poor sleep, while those with a mild injury may be more aware of the changes in their sleep patterns and over report any changes that have occurred as a result of the injury (Elovic et al. 2005). Castriotta et al. (2007) found that 47% of individuals with TBI reported EDS. In a Canadian study, Ouellet et al. (2006) found, using subjective measures, that approximately 50% of their TBI sample (total n=452) reported symptoms of insomnia and those that did not report insomnia as a problem were sleeping more than before the injury. Individuals with insomnia reported having sleep difficulties 5.7 times per week (Ouellet et al. 2006). It was also noted that more than half of the individuals who reported having sleep difficulties were not being treated for the condition (Ouellet et al. 2006).
The studies in the table above show that there are many different sleep disorders experienced by patients with brain injury including daytime sleepiness (Imbach et al. 2016; Imbach et al. 2015; Kempf et al. 2010; Ponsford et al. 2013; Sinclair et al. 2014), poor sleep quality, insomnia (Cantor et al. 2012; Gardani et al. 2015; Kempf et al. 2010; Ponsford et al. 2013; Verma et al. 2007), sleep disorganization (Nakase-Richardson et al. 2013), sleep wake disturbance, and hypersomnia (Gardani et al. 2015; Kempf et al. 2010). Daytime sleepiness and the increased need for sleep remains a problem in the short and long term following a brain injury (Imbach et al. 2016; Imbach et al. 2015). Even more problematic is the finding that individuals underestimate their sleep disturbances, as they report significantly less problems of excessive daytime sleepiness on subjective compared to objective measures (Imbach et al. 2016; Imbach et al. 2015).
Individuals with sleep disturbances have longer length of stay in hospital (Duclos et al. 2014; Nakase-Richardson et al. 2013; Sandsmark et al. 2016). Further, increased injury severity is associated with more disturbances in sleep and wake cycles (Duclos et al. 2014). Sandsmark et al. (2016) found that sleep disturbances recorded through electrophysiological measures were associated with unfavourable outcomes and fewer opportunities for rehabilitation. Nakase-Richardson et al. (2013) discovered that the duration of post-traumatic amnesia was longer when moderate to severe sleep disorders were present. Gardani et al. (2015) report that in severe brain injuries, insomnia and sleep quality are associated with anxiety during subacute-chronic rehabilitation. Moreover, Cantor et al. (2012) found that at one year insomnia was associated with the presence of anxiety, major depression, and poor sleep quality. Whereas, at two years, the presence of anxiety, higher discharge cognitive Functional Independence Measure scores and poorer sleep quality were predictors of insomnia (Cantor et al. 2012). Fichtenberg et al. (2000) also noted the association between insomnia, pain disturbance, and depression. A study by Wiseman-Hakes et al. (2013) supported the concept that sleep disturbances associated with TBI exacerbate cognitive, communication and mood deficits that are trauma-related. Dealing with sleep disturbances is necessary for optimal recovery.