Original ArticleSleepiness and fatigue following traumatic brain injury
Introduction
Regarded as a “silent epidemic,” traumatic brain injury (TBI) is a major public health issue with an incidence of 1,565,000 in the US in 2003 [1]. Although the vast majority of injuries are classified as mild, more severe TBI is associated with poorer outcome, as illustrated by a 43.3% long-term disability rate among injuries necessitating hospitalization [2]. In addition to more noticeable consequences in the physical, psychiatric, and cognitive domains, sleepiness, fatigue, and sleep disturbances are increasingly recognized as prevalent and persistent outcomes following TBI.
According to recent reviews, 30–70% of TBI survivors report sleep–wake disturbances [3]. Excessive sleepiness is one of the most common ones, both as a self-reported complaint assessed by questionnaires and as an objective physiological symptom measured by daytime polysomnography [4], [5], [6]. Sleepiness may present as a stand-alone symptom or as part of a sleep disorder such as sleep apnea, narcolepsy, or post-traumatic hypersomnia [3], [7]. In many cases, sleep–wake disturbances are directly related to the brain trauma, persist for months or years after the injury, and may impede the recovery process and return to premorbid functioning [3], [8], [9]. Fatigue is also a very common symptom following TBI, with prevalence estimates ranging from 43% to 73% by self-report [10]. Fatigue is chronic in many cases, remaining as prevalent several years after the TBI [11], [12], and has been linked to impairments in quality of life, instrumental activities of daily living, and social functioning [11], [13].
Despite overlapping features leading patients, clinicians and researchers alike to confuse them, sleepiness and fatigue are distinct concepts [14], [15]. For instance, sleepiness can be defined as the “inability to maintain a desired level of alertness or wakefulness during the day” [16] while “central” (as opposed to peripheral or muscular) fatigue is a multifaceted phenomenon which has been described as the “failure to initiate or sustain attentional tasks (“mental fatigue”) and physical activities (“physical fatigue”) requiring self motivation” [17]. Further complicating their differentiation is the fact that both sleepiness and fatigue can be present in specific populations and both can be exacerbated by underlying sleep disorders. Thus, it is crucial to investigate these phenomena concurrently in order to better understand their common and unique manifestations and ultimately orient treatment plans. Only a few studies have done so in individuals with TBI. An investigation of 76 consecutive TBI patients conducted six months after the injury suggested that sleepiness, fatigue and hypersomnia were the most prevalent sleep–wake disturbances [18]. The same sample was re-assessed three years post-injury, showing an increase in the prevalence of fatigue and a decrease in the prevalence of sleepiness [8]. Chaumet et al. observed that, while subjective fatigue correlated with sleepiness in TBI individuals at least six months after their injury, the levels of both objective and subjective sleepiness were within the normal range and did not significantly differ from those of healthy controls [19].
Despite emerging scientific literature in recent years, little is known, still, regarding the nature, course, and correlates of sleepiness and fatigue following TBI, especially after more severe injuries. Indeed, most published studies have been conducted on samples including mild TBIs only or combined with moderate/severe TBIs despite the well documented discrepancies in expected short- and long-term outcomes between these severity levels. This study aimed to (1) compare individuals with moderate/severe TBI assessed at least one year post-injury to matched healthy controls on measures of sleepiness, fatigue, and sleep, and (2) explore correlates of sleepiness and fatigue separately for each group.
Section snippets
Methods
The study protocol was approved by the Institutional Research Ethics Boards of the Institut de réadaptation en déficience physique de Québec and the Centre de recherche Université Laval Robert-Giffard, both affiliated with Université Laval, Québec, Canada.
Sample description
Table 1 presents between-group comparisons on participants’ characteristics and Table 2 presents sociodemographic and clinical characteristics for each TBI participant. Groups were comparable on age, education, and gender, validating the matching procedure. TBI and CTL groups were not significantly different on body mass index (BMI) and marital status. Participants with TBI were significantly less likely than CTLs to be currently working or studying and more likely to be on long-term medical
Discussion
This study explored the presence and severity of sleepiness and fatigue 1–11 years following moderate to severe TBI. Results revealed that subjective fatigue was higher in the TBI group compared to the CTL group. TBI participants were very alert and did not differ from CTLs on objective and on most subjective measures of sleepiness, but reported a greater impact of sleepiness on daily functioning, spent more time in bed, and napped more frequently and for a longer time during the day compared to
Conflict of interest
The ICMJE Uniform Disclosure Form for Potential Conflicts of Interest associated with this article can be viewed by clicking on the following link: doi:10.1016/j.sleep.2012.02.010.
Acknowledgements
This study was supported by a doctoral fellowship awarded to Simon Beaulieu-Bonneau, M.Ps., by the Canadian Institutes of Health Research. We are grateful to Hans Ivers, Ph.D., for statistical support, and to Marie-Christine Ouellet, Ph.D., for comments on the manuscript.
References (49)
- et al.
Excessive daytime sleepiness in adults with brain injuries
Arch Phys Med Rehabil
(2001) - et al.
Fatigue and basal ganglia
J Neurol Sci
(2000) - et al.
Assessment of coma and impaired consciousness. A practical scale
Lancet
(1974) - et al.
The Multidimensional Fatigue Inventory (MFI): psychometric qualities of an instrument to assess fatigue
J Psychosom Res
(1995) - et al.
Self-reported changes to nighttime sleep after traumatic brain injury
Arch Phys Med Rehabil
(2006) - et al.
Sleep apnea in adults with traumatic brain injury: a preliminary investigation
Arch Phys Med Rehabil
(2001) - et al.
Incidence of traumatic brain injury in the United States, 2003
J Head Trauma Rehabil
(2006) - et al.
Incidence of long-term disability following traumatic brain injury hospitalization, United States, 2003
J Head Trauma Rehabil
(2008) - et al.
Traumatic brain injury and sleep disturbance: a review of current research
J Head Trauma Rehabil
(2009) - et al.
Prevalence and consequences of sleep disorders in traumatic brain injury
J Clin Sleep Med
(2007)
Sleep disorders in chronic traumatic brain injury
J Clin Sleep Med
Sleep disorders in patients with traumatic brain injury: a review
CNS Drugs
Sleep–wake disturbances 3 years after traumatic brain injury
J Neurol Neurosurg Psychiatry
Rehabilitation is compromised by arousal and sleep disorders: results of a survey of rehabilitation centres
Brain Inj
Fatigue and traumatic brain injury
Ann Readapt Med Phys
Fatigue following traumatic brain injury: frequency, characteristics, and associated factors
Rehabil Psychol
Measurement and prediction of subjective fatigue following traumatic brain injury
J Int Neuropsychol Soc
Fatigue after traumatic brain injury and its impact on participation and quality of life
J Head Trauma Rehabil
Fatigue and sleep
Clinical complaints of daytime sleepiness and fatigue: how to distinguish and treat them, especially when they become ‘excessive’ or ‘chronic’?
Acta Neurol Belg
The International Classification of Sleep Disorders
Sleep–wake disturbances 6 months after traumatic brain injury: a prospective study
Brain
Is there a link between alertness and fatigue in patients with traumatic brain injury?
Neurology
Orientations ministérielles pour le traumatisme craniocérébral léger 2005–2010 [Ministerial guidelines for the management of mild traumatic brain injury 2005–2010]
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