A Systematic Review of Sleep in Patients with Disorders of Consciousness: From Diagnosis to Prognosis

Abstract

With the development of intensive care technology, the number of patients who survive acute severe brain injury has increased significantly. At present, it is difficult to diagnose the patients with disorders of consciousness (DOCs) because motor responses in these patients may be very limited and inconsistent. Electrophysiological criteria, such as event-related potentials or motor imagery, have also been studied to establish a diagnosis and prognosis based on command-following or active paradigms. However, the use of such task-based techniques in DOC patients is methodologically complex and requires careful analysis and interpretation. The present paper focuses on the analysis of sleep patterns for the evaluation of DOC and its relationships with diagnosis and prognosis outcomes. We discuss the concepts of sleep patterns in patients suffering from DOC, identification of this challenging population, and the prognostic value of sleep. The available literature on individuals in an unresponsive wakefulness syndrome (UWS) or minimally conscious state (MCS) following traumatic or nontraumatic severe brain injury is reviewed. We can distinguish patients with different levels of consciousness by studying sleep patients with DOC. Most MCS patients have sleep and wake alternations, sleep spindles and rapid eye movement (REM) sleep, while UWS patients have few EEG changes. A large number of sleep spindles and organized sleep–wake patterns predict better clinical outcomes. It is expected that this review will promote our understanding of sleep EEG in DOC.

Neuroimaging and neurophysiological diagnosis and prognosis in paediatric disorders of consciousness

“…Moreover, they confirmed that the higher the global complexity of the polysomnography signal in UWS (e.g. prevalence of slow‐wave activity [SWA] vs mixed frequency EEG with rhythmic theta anterior activity), the better the functional outcome for the patient, as demonstrated previously in the adult population 21 …”

“…prevalence of slow-wave activity [SWA] vs mixed frequency EEG with rhythmic theta anterior activity), the better the functional outcome for the patient, as demonstrated previously in the adult population. 21 In line with this research, Mouthon et al 22 collected data on sleep in children with DOC, this time focusing on SWA. High-density EEGs during sleep were recorded twice at different time intervals in 10 typically developing children, five children with acquired brain injury but no DOC, and five children with DOC after acquired brain injury (four in MCS and one emergent from MCS, diagnosed daily with the CRS-R).…”

The Integration of Assistive Technology and Virtual Reality for Assessment and Recovery of Post-coma Patients With Disorders of Consciousness: A New Hypothesis

“…Thus, empirical evidences of P300 or mismatch negativity are usually viewed as basic signs of awareness or consciousness with meaningful implications for the recovery process (Estraneo et al, 2022 ; Pruvost-Robieux et al, 2022 ). Recent reviews (Pan et al, 2021 ; Aubinet et al, 2022 ) critically discussed the use of event-related potentials and emphasized the strengths to use multiple measures to enhance the significance of the findings (Calabrò et al, 2021 ).…”

Sleep and Circadian Disturbance in Disorders of Consciousness: Current Methods and the Way towards Clinical Implementation

“…MCS can be further categorized into MCS+ and MCS-based on the preservation or loss of language related functions 16 . It has been argued that MCS patients potentially show increasingly normal sleep architecture 5 .…”