Background:
Light is the most important regulator of circadian rhythm. Naturalistic light, which contains the spectrum of sunlight throughout the day, has been shown to have a positive impact on mental states such as depression and fatigue in stroke and other diseases requiring long-term hospitalization.
Depression and fatigue are very common complications after stroke, with a frequency of 30% and 85%, respectively. Both are significantly related to reduced quality of life and early death. Both the causes and pathophysiology behind these complications are unknown, but it is assumed that disturbances (inflammation and cell death) in brain areas and brain networks related to arousal, sleep, circadian rhythm, and the frontal lobe play a role.
The hypothesis is that it is possible to detect changes in brain networks related to depression and fatigue by MRI, and that naturalistic light will affect these changes.
Method:
Stroke patients requiring a minimum of 10 days of rehabilitation are transferred to a neurorehabilitation unit with naturalistic lighting.
Examination:
Validated tests for fatigue, depression, sleep and cognitive functions.
Pathophysiological studies:
* MRI focusing on cerebral blood flow, metabolism, and cerebral networks. * Spinal fluid analyses for hormones and markers involved in immunological response as well as wakefulness/arousal and depression. * Sleep assessments.
Patients scoring moderate-severe fatigue and/or depression OR NO fatigue and/or depressione which are evaluated as candidates for the rehabilitation unit.
GCS < 15
No functioning nervus opticus or retina in both eyes
Unable to open both eyes
Non communicating patients e.g. severe aphasia (incompetent patients)
Single group
Naturalistic Light Intervention
DeviceNaturalistic light as an Intervention A 24-hour naturalistic lighting scheme is implemented in all areas and rooms in the unit at Rigshospitalet Glostrup with a computer-controlled lighting scheme (ChromaViso, Denmark). The naturalistic lighting scheme is constantly running. The lighting imitate the sunlight rhythm following the principles of Lucas et al.
Fatigue and depression
Primary hypothesis: Naturalistic light reduce the major depression inventory questionnaire score and multidimensional fatigue inventory questionnaire score from baseline til discharge. Mood-related network will too show positive changes measured by whole brain resting-state connectivity in post-stroke patients compared with a control group without fatigue and depression.
Cognitive function
Secondary hypothesis: Naturalistic light improves executive cognitive function and processing speed in test included in the Neuropsychology assessments (Verbal fluency, 1 minute each per test: Category fluency (animals) and lexical fluency (s words and a words), System Digit Modalities Test (SDMT), and Stroop test) and furthermore modifies cognitive related network activation measured by fMRI in post-stroke patients compared with a control group without cognitive impairment.
Sleep quality
Secondary hypothesis: Naturalistic light improves sleep quality from baseline to discharge measured by polysomnography and Pittsburgh Sleep Quality Index questionnaire in post-stroke patients compared with a control group without poor sleep quality.
Hypocretin
Secondary hypothesis: Naturalistic light increase hypocretin levels from baseline to discharge in post stroke patients with measured fatigue and sleepiness compared to a control group without fatigue and sleepiness.
CFS inflammation
Secondary hypothesis: The severity of post stroke fatigue and post stroke depression is associated to the level of markers related to cerebral inflammation based on measured CFS inflammation and naturalistic light will decrease this inflammation compared to a control group without fatigue and depression.
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Rigshospitalet, Denmark
Lead sponsor
Chromaviso A/S
Collaborator
