Stimulus-driven cerebrospinal fluid dynamics is impaired in glaucoma patients

Area of Science:

• Neuroscience
• Ophthalmology
• Fluid Dynamics

Background:

• Cerebrospinal fluid (CSF) flow is vital for homeostasis and waste removal, partly driven by sensory stimulation.
• The impact of age-related visual neurodegenerative diseases on stimulus-driven CSF dynamics is not well understood.

Purpose of the Study:

• To investigate alterations in CSF flow during visual stimulation in glaucoma patients compared to healthy older adults.
• To explore the relationship between visual evoked brain activity and CSF dynamics in glaucoma.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was employed to simultaneously assess CSF flow and blood-oxygen-level-dependent (BOLD) responses during visual stimulation.
• Mediation analysis was used to determine the relationship between BOLD signal changes and CSF pattern alterations.

Main Results:

• Glaucoma patients exhibited a decoupling of CSF inflow from the visually evoked BOLD response.
• The typical stimulus-locked CSF patterns were diminished in glaucoma, correlating with disease severity.
• A flatter ascending BOLD slope in glaucoma patients led to a reduced CSF trough and post-stimulus surge.

Conclusions:

• Glaucoma is associated with impaired visually driven CSF inflow, linked to functional deficits in the visual system.
• These findings suggest that glaucoma-related functional impairments contribute to altered CSF dynamics.
• This study offers potential in vivo biomarkers for monitoring CSF dynamics in glaucoma.