Regional neurodegeneration correlates with sleep-wake dysfunction after stroke.

Area of Science:

• Neuroscience
• Sleep Medicine
• Neurology

Background:

• Sleep-wake disruption is a significant, treatable risk factor and consequence of stroke.
• The underlying causes of post-stroke sleep disturbances remain unclear, with possibilities including focal brain lesions or accelerated neurodegeneration.

Purpose of the Study:

• To investigate the relationship between objectively measured sleep-wake dysfunction and brain structural changes in stroke survivors.
• To identify specific regional brain volumes and white matter alterations associated with prolonged sleep duration and reduced sleep efficiency post-stroke.

Main Methods:

• A prospective study involving 112 stroke survivors and 35 healthy controls, measuring sleep using the SenseWear Armband.
• Utilized regional brain volumetry and whole-brain, fiber-specific, fixel-based analysis to assess white matter integrity.
• Compared stroke participants with long sleep duration (>8 hours) or poor sleep efficiency (<80%) to controls with optimal sleep.

Main Results:

• Stroke survivors with long sleep duration had reduced volumes in the ipsilesional thalamus and contralesional amygdala compared to controls.
• Poor sleep efficiency was linked to smaller volumes in the ipsilesional thalamus, contralesional hippocampus, and contralesional amygdala.
• Fixel-based analysis revealed significant white matter degeneration (up to 40% fiber reduction) in the corticopontocerebellar tract among stroke survivors with long sleep duration.

Conclusions:

• Accelerated neurodegeneration in subcortical structures may underlie sleep-wake disturbances after stroke, irrespective of lesion location or other health issues.
• These findings highlight the role of neurodegeneration in post-stroke sleep pathology and its potential clinical implications.