Relationship between cerebral perfusion and cognition in white matter hyperintensities of presumed vascular origin: A prospective 3D-pCASL study.

No clusters with CBF differences at the shorter post-labeling delay (1525 ms) were identified among the four Fazekas grade groups.

• 128 participants underwent 3D-pCASL imaging with post-labeling delay (PLD) values of 1525 ms and 2525 ms
• MRI results were categorized into 4 groups based on the Fazekas visual rating scale
• Variance analyses were conducted among the 4 groups for CBF at both PLD values
• No clusters with CBF1525ms differences were identified among the 4 groups

Three clusters with CBF differences at the longer post-labeling delay (2525 ms) were identified among the four Fazekas grade groups.

• Three distinct brain region clusters showed significant CBF2525ms differences among the 4 Fazekas grade groups
• The clusters were located in the left lenticular nucleus, right lenticular nucleus, and left thalamus/hippocampus
• CBF2525ms in these brain regions showed an increasing trend with increasing Fazekas grades
• The longer PLD of 2525 ms was necessary to detect these perfusion differences, suggesting involvement of slower collateral circulation

CBF2525ms in the left lenticular nucleus was negatively correlated with both MMSE and MoCA cognitive scores.

• Negative correlation between left lenticular nucleus CBF2525ms and MMSE scores: r = -0.306, P < .001
• Negative correlation between left lenticular nucleus CBF2525ms and MoCA scores: r = -0.269, P = .002
• Partial correlation analyses were used to assess relationships between CBF and cognitive function
• Higher CBF in this region was associated with worse cognitive performance

CBF2525ms in the right lenticular nucleus was negatively correlated with both MMSE and MoCA cognitive scores.

• Negative correlation between right lenticular nucleus CBF2525ms and MMSE scores: r = -0.177, P = .047
• Negative correlation between right lenticular nucleus CBF2525ms and MoCA scores: r = -0.179, P = .045
• Correlations in the right lenticular nucleus were weaker than those observed in the left lenticular nucleus
• Both correlations reached statistical significance at the P < .05 threshold

CBF2525ms in the left thalamus/hippocampus was negatively correlated with both MMSE and MoCA cognitive scores.

• Negative correlation between left thalamus/hippocampus CBF2525ms and MMSE scores: r = -0.226, P = .011
• Negative correlation between left thalamus/hippocampus CBF2525ms and MoCA scores: r = -0.220, P = .013
• This region was one of three clusters identified as showing CBF2525ms differences among Fazekas grade groups
• Higher perfusion in this region at the longer PLD was associated with worse cognitive performance

The study interpreted increased CBF2525ms in certain brain regions with higher WMH severity as evidence of collateral circulation compensating for vascular pathology.

• CBF measured at the longer PLD of 2525 ms captures blood that has traveled through slower, longer pathways consistent with collateral circulation
• The increasing trend of CBF2525ms with increasing Fazekas grades in affected regions supports a collateral circulation mechanism
• The negative correlation between this elevated CBF and cognitive scores suggests collateral perfusion does not preserve cognitive function
• The authors concluded that 'more severe WMH may increase perfusion through collateral circulation in certain brain regions'

The study enrolled 128 participants who underwent both cognitive assessments and 3D-pCASL MRI imaging.

• This was a prospective study design
• All 128 participants underwent cognitive assessments including MMSE and MoCA
• All participants underwent a three-dimensional pseudo-continuous arterial spin labeling (3D-pCASL) sequence
• Two post-labeling delay values of 1525 ms and 2525 ms were used
• MRI results were classified using the Fazekas visual rating scale into 4 groups