Morphologic and functional alterations in the parasagittal dural space in mild cognitive impairment

Abstract

This study aimed to identify morphologic and functional differences in the parasagittal dural space (PSD) between patients with mild cognitive impairment (MCI) and cognitively unimpaired participants using dynamic contrast-enhanced MRI (DCE MRI). A total of 29 MCI patients and nine controls underwent structural MRI and DCE MRI, where PSD volume and parameters such as peak wash-in rate and time to first peak enhancement were assessed. MCI patients had significantly larger PSD volume (P = 0.023), a lower peak wash-in rate (P < 0.001), and delayed time to first peak (P = 0.001) compared to controls. In multivariate regression analysis, PSD volume (β = -0.579, 95% CI [-1.072 - -0.086], P = 0.023) and wash-out rate (β = -3.293, 95% CI [-6.351 - -0.235], P = 0.036) were significantly associated with the Mini-Mental State Examination (MMSE) score. Additionally, a lower peak wash-in rate correlated significantly with lower cognitive performance, as measured by the Montreal Cognitive Assessment (MoCA) (P = 0.043). This association highlights a potential link between meningeal lymphatic dysfunction and cognitive decline, suggesting that PSD alterations could reflect early stages of neurodegenerative changes. In conclusion, these PSD structural and functional alterations in MCI patients may serve as early imaging markers, helping in the assessment of disease severity in neurodegenerative conditions such as Alzheimer's disease. This insight into meningeal lymphatic dysfunction provides a promising direction for early diagnosis and monitoring of cognitive impairment.

Keywords: Dementia; Dynamic contrast-enhanced imaging; Magnetic resonance imaging; Meningeal lymphatic system; Mild cognitive impairment.

Fig. 1

Flowchart of patient inclusion.

Fig. 2

Structural and functional imaging analysis of parasagittal dural space using brain MRI. DCE-MRI: dynamic contrast enhanced magnetic resonance imaging; CE 3D T1 BB images: contrast-enhanced 3-dimensional T1-weighted black-blood images.

Fig. 3

A schematic presentation of time-intensity curve used as the basis for the assessment of DCE parameters of PSD. In cases where multiple signal peaks were observed, the first peak—defined as the phase when the signal reaches its initial peak and begins to decline, or reaches its first plateau—was used to calculate the time to the first peak.

Fig. 4

Normalized time-intensity curves for PSD depicted with mean values and 95% confidence interval in cognitively unimpaired and MCI subjects.