Understanding the influence of sleep, a modifiable behavior, in different neuropsychological populations

Open Access
- Author:
- Riegler, Kaitlin Elizabeth
- Graduate Program:
- Psychology
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- May 12, 2023
- Committee Members:
- Frank Hillary, Major Field Member
Nancy Dennis, Major Field Member
Semyon Slobounov, Outside Unit & Field Member
Peter Arnett, Chair & Dissertation Advisor
Kristin Buss (she/her), Program Head/Chair - Keywords:
- Sleep
Multiple Sclerosis
Concussion - Abstract:
- Poor sleep can have long-term consequences such as risk for cognitive impairments and worse outcomes later in life. Beyond formal sleep disorders, medical and psychiatric conditions such as disorders and injuries to the brain are associated with sleep disruption. Poor sleep has several negative consequences for healthy individuals and these consequences may be more pronounced in individuals more prone to experience sleep disturbances or who have medical or psychiatric conditions that contribute to sleep difficulties. For instance, two neuropsychological populations that may be particularly prone to sleep difficulties and disturbances are college athletes sustaining sport-related concussion (SRC) and persons with Multiple Sclerosis (PwMS). Individuals in both groups are also more likely to experience cognitive impairments and psychological sequalae, including depression and decreased quality of life (QoL). Therefore, understanding the combined effect of either concussion or MS and poor sleep on cognitive functioning and overall QoL is important, especially given that sleep is a modifiable behavior that may be targeted in treatment. The overarching goal of this three-paper dissertation is to examine sleep, a modifiable behavior, as a secondary symptom in two neuropsychological populations: SRC and MS. First, this dissertation examined the implications of insufficient sleep in athletes at baseline, and factors such as symptom reporting and neurocognitive performance at baseline associated with insufficient sleep, for risk of SRC. Results found that insufficient sleepers at baseline were nearly twice as likely to sustain an SRC than sufficient sleepers at baseline. Additionally, insufficient sleepers, whether or not they went on to sustain an SRC, reported a higher number of baseline symptoms compared to sufficient sleepers. When compared to either insufficient sleepers who did not go on to get an SRC or to sufficient sleepers that did go on to sustain an SRC, the insufficient sleep group that went on to sustain an SRC performed worse at baseline on a composite of attention/processing speed tasks. Second, this dissertation examined the relationship between sleep disturbances and outcomes following SRC and explored athlete and injury variables, including loss of consciousness, continuing to play after sustaining SRC, and history of prior concussions, that may be related to the mechanisms for sleep disturbances following SRC. The results indicated that sleep disturbed athletes reported more overall symptoms, were more likely to be symptomatic, and were marginally more likely to experience clinically significant depression at the time of testing compared to not sleep disturbed athletes. Additionally, a greater proportion of the sleep disturbed athletes experienced loss of consciousness at the time of their concussion, indicating that this may be a potential mechanism leading to sleep disturbances. Third, this dissertation explored group differences between PwMS with poor and normal sleep quality on cognitive functioning and QoL and examined the impact of sleep quality on QoL over and above illness and clinical variables. The results indicated that poor and normal sleep quality PwMS did not differ in terms of objective cognitive functioning, but a greater proportion of poor sleep quality PwMS reported that sleep patterns affected their cognitive abilities. Additionally, poor sleep quality PwMS reported significantly worse QoL in domains of symptoms, thinking, and fatigue, and even after accounting for disability status, depression, and fatigue, sleep quality was significantly predictive of symptoms and fatigue QoL. The results of these three studies will provide clinicians with information that can be used to better understand the cumulative impact of poor sleep in the context of acquired brain injury (concussion) or neurodegenerative disease (MS) in order to better target behavioral interventions with the goal of improving outcomes and quality of life.