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Updated: May 7, 2026
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Decreased DTI-ALPS index in delirium: a preliminary MRI study
Ye Tu1,2,3, Renjie Song4, Fei Xiong5
1Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Purpose:
Delirium is linked to brain abnormalities, yet the role of the glymphatic system is not well understood. This study aims to examine alterations in brain physiology in delirium by using diffusion-tensor imaging (DTI) to assess water diffusion along the perivascular space (ALPS) and to explore its correlation with clinical symptoms.
Methods:
We examined 15 patients with delirium and 15 healthy controls, measuring water diffusion metrics along the x-, y-, and z-axes in both projection and association fibers to determine the DTI-ALPS index. We used a general linear model, adjusted for age and sex, to compare the DTI-ALPS index between groups. We also investigated the relationship between the DTI-ALPS index and clinical symptoms using partial correlations.
Results:
Patients with delirium exhibited significantly lower DTI-ALPS indices compared to healthy controls (1.25 ± 0.15 vs. 1.38 ± 0.10, t = 2.903, p = 0.007; 1.27 ± 0.16 vs. 1.39 ± 0.08, 1.22 ± 0.16 vs. 1.37 ± 0.14, t = 2.617, p = 0.014; t = 2.719, p = 0.011; respectively). However, there was no significant correlation between the DTI-ALPS index and clinical symptoms.
Conclusion:
Our findings indicate a decreased DTI-ALPS index in patients with delirium, suggesting potential alterations in brain physiology that may contribute to the pathophysiology of delirium. This study provides new insights into the mechanisms underlying delirium.
Insights
Patients with delirium show reduced water diffusion along the perivascular space (ALPS) as measured by diffusion-tensor imaging (DTI). This suggests glymphatic system dysfunction may contribute to delirium pathophysiology.
Area of Science:
- Neuroscience
- Radiology
- Geriatrics
Background:
- Delirium is associated with brain abnormalities, but the glymphatic system's role remains unclear.
- The glymphatic system facilitates waste clearance in the brain, and its dysfunction is implicated in various neurological conditions.
Purpose of the Study:
- To investigate alterations in brain physiology in delirium patients using diffusion-tensor imaging (DTI).
- To assess water diffusion along the perivascular space (ALPS) as a marker of glymphatic function.
- To explore the correlation between DTI-ALPS index and clinical symptoms of delirium.
Main Methods:
- Diffusion-tensor imaging (DTI) was used to measure water diffusion metrics.
- The diffusion-tensor imaging-aquaporin-like space (DTI-ALPS) index was calculated for 15 delirium patients and 15 healthy controls.
- General linear models and partial correlations were employed for statistical analysis.
Main Results:
- Delirium patients exhibited significantly lower DTI-ALPS indices compared to healthy controls (p < 0.014).
- No significant correlation was found between the DTI-ALPS index and the severity of clinical symptoms in delirium patients.
Conclusions:
- A decreased DTI-ALPS index in delirium suggests impaired glymphatic system function.
- These findings provide novel insights into the pathophysiology of delirium, highlighting potential glymphatic system involvement.
- Further research is warranted to elucidate the precise mechanisms linking glymphatic dysfunction to delirium.
