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Updated: May 4, 2026
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Glymphatic function from diffusion-tensor MRI to predict conversion from mild cognitive impairment to dementia in
Huize Pang1, Juzhou Wang1, Ziyang Yu2
1Department of Radiology, First Affiliated Hospital of China Medical University, Shenyang, Liaoning, China.
Background:
Although brain glymphatic dysfunction is a contributing factor to the cognitive deficits in Parkinson's disease (PD), its role in the longitudinal progression of cognitive dysfunction remains unknown.
Objective:
To investigate the glymphatic function in PD with mild cognitive impairment (MCI) that progresses to dementia (PDD) and to determine its predictive value in identifying individuals at high risk for developing dementia.
Methods:
We included 64 patients with PD meeting criteria for MCI and categorized them as either progressed to PDD (converters) (n = 29) or did not progress to PDD (nonconverters) (n = 35), depending on whether they developed dementia during follow-up. Meanwhile, 35 age- and gender-matched healthy controls (HC) were included. Bilateral diffusion-tensor imaging analysis along the perivascular space (DTI-ALPS) indices and enlarged perivascular spaces (EPVS) volume fraction in bilateral centrum semiovale, basal ganglia (BG), and midbrain were compared among the three groups. Correlations among the DTI-ALPS index and EPVS, as well as cognitive performance were analyzed. Additionally, we investigated the mediation effect of EPVS on DTI-ALPS and cognitive function.
Results:
PDD converters had lower cognitive composites scores in the executive domains than did nonconverters (P < 0.001). Besides, PDD converters had a significantly lower DTI-ALPS index in the left hemisphere (P < 0.001) and a larger volume fraction of BG-PVS (P = 0.03) compared to HC and PDD nonconverters. Lower DTI-ALPS index and increased BG-PVS volume fraction were associated with worse performance in the global cognitive performance and executive function. However, there was no significant mediating effect. Receiver operating characteristic analysis revealed that the DTI-ALPS could effectively identify PDD converters with an area under the curve (AUC) of 0.850.
Conclusion:
The reduction of glymphatic activity, measured by the DTI-ALPS, could potentially be used as a non-invasive indicator in forecasting high risk of dementia conversion before the onset of dementia in PD patients.
Insights
Reduced brain glymphatic function, measured by DTI-ALPS, predicts dementia conversion in Parkinson's disease (PD) patients with mild cognitive impairment (MCI). This non-invasive indicator aids in forecasting high-risk individuals before dementia onset.
Area of Science:
- Neuroscience
- Neurology
- Medical Imaging
Background:
- Glymphatic system dysfunction contributes to cognitive deficits in Parkinson's disease (PD).
- The role of glymphatic dysfunction in the longitudinal progression of cognitive decline in PD is not well understood.
Purpose of the Study:
- To investigate glymphatic function in PD patients with mild cognitive impairment (MCI) who progress to dementia (PDD).
- To determine if glymphatic function can predict dementia development in PD patients.
Main Methods:
- Compared diffusion-tensor imaging analysis along the perivascular space (DTI-ALPS) and enlarged perivascular spaces (EPVS) in PD patients with MCI (converters to PDD and non-converters) and healthy controls (HC).
- Assessed cognitive performance and analyzed correlations between DTI-ALPS, EPVS, and cognitive function.
Main Results:
- PDD converters showed lower DTI-ALPS indices and larger basal ganglia-PVS volume fractions compared to HC and non-converters.
- Reduced DTI-ALPS and increased basal ganglia-PVS were associated with poorer global and executive cognitive function.
- DTI-ALPS effectively identified PDD converters with an AUC of 0.850.
Conclusions:
- Reduced glymphatic activity, indicated by DTI-ALPS, can serve as a non-invasive marker for predicting dementia risk in PD patients.
- This finding offers a potential tool for early identification of individuals at high risk for dementia conversion.
