An investigation into sleep quality after stroke
Keywords: Stroke
MRI
CBT
Sleep
Actigraphy

Background:
It has been well established that sleep plays an important role in the consolidation of memory, which is useful for skill learning. Following stroke, many survivors are tasked with re-learning skills that have been affected by stroke. Many stroke survivors report difficulty sleeping, including difficulty initiating sleep, disrupted sleep and excessive daytime tiredness. If sleep quality is negatively affected by stroke, rehabilitation may be suboptimal as memory consolidation could be diminished and risk of long-term additional health problems could be increased.
Aims:
1. To establish whether there is a difference in the sleep quality between stroke survivors and healthy controls.
2. To understand whether there any neural correlates to poorer sleep after stroke.
3. To investigate whether a current digital Cognitive Behaviour Therapy treatment for sleep would be usable by a stroke cohort.
Methods and Results:
Study 1 – Sleep quality was measured for a group of 50 stroke survivors and 50 healthy controls with actigraphy monitors. It was found that the stroke group had significantly poorer sleep than the controls, even when accounting for age. Specifically, stroke survivors experienced reduced total sleep time and showed larger numbers of wakenings and total time spent awake during their sleep periods. No individual characteristics such as depression, daily activity or medications accounted for differences in objective sleep quality within the stroke group.
Study 2 - A subset of 15 stroke survivors from study 1 received structural MRI scans to test for relationships between lesion volume, grey matter volume and sleep quality. No significant relationships were found between any of the measures examined.
Study 3 - The feasibility of the dCBT programme ‘Sleepio’ was assessed amongst 11 stroke survivors. A significant relationship between age and time taken to complete the programme was found, suggesting that older users may find the programme more difficult to use. Of the 11 participants, 6 have completed the programme to date and were invited for an interview to discuss the feasibility of usage. It was found that the programme, while technically feasible to be used within this cohort, suggested implementing a number of changes that were not practical for stroke survivors with different disabilities, and aspects of the initial usage of the programme were difficult to follow.
Conclusions:
Given the multifaceted process of sleep it is very difficult to point to the driving component behind stroke that leads to poorer sleep. Aspects of stroke and its common outcomes, such as reduced mobility, pain, depression and location of lesion may collectively contribute to a reduction in sleep quality, although no single element has been identified as the main contributor to the change. Current therapies for sleep improvement appear to be appropriate to be used within this cohort, although some alterations may need to be made to make them more inclusive of stroke related disabilities. Given the overall feasibility of existing dCBT treatments for stroke survivors, efficacy research should be carried out on this cohort, as it has previously been shown to be effective within insomnia groups.