CSF/serum folate gradient: physiology and determinants with special reference to dementia

Area of Science:

• Neuroscience
• Biochemistry
• Gerontology

Background:

• Folate deficiency is linked to neurodegenerative diseases.
• Cerebrospinal fluid (CSF) folate transport may play a role in neurodegeneration.
• Investigating folate transport mechanisms is crucial for understanding cognitive disorders.

Purpose of the Study:

• To investigate the relationship between the CSF/serum folate gradient (R(CSF/S)) and cognitive disorders.
• To characterize the R(CSF/S) in relation to clinical and biochemical markers.
• To assess the integrity of the blood-CSF barrier in relation to folate transport.

Main Methods:

• Studied the CSF/serum folate gradient (R(CSF/S)) in 205 subjects with suspected cognitive impairment.
• Correlated R(CSF/S) with clinical and biochemical indices.
• Assessed the blood-CSF barrier integrity using the albumin ratio.

Main Results:

• The R(CSF/S) was significantly lower in subjects with vascular dementia (VaD) and mixed dementia compared to non-demented (ND) subjects.
• ND subjects had higher CSF folate and lower serum homocysteine than VaD + mixed subjects.
• R(CSF/S) correlated negatively with serum folate and the albumin ratio (blood-CSF barrier integrity).

Conclusions:

• A reduced R(CSF/S) suggests impaired folate transport across the choroid plexus in VaD + mixed dementia.
• This folate transport defect appears specific to the VaD + mixed dementia subgroup.
• Findings highlight a potential mechanism in the pathophysiology of vascular dementia.