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Updated: Jun 9, 2026
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Association of the DTI-ALPS index with motor and non-motor symptoms in Parkinson's disease with postural
Peixian Ji1, Yunxin Xie1, Yongfeng Jia1
1Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, No. 300 Guangzhou Road, Nanjing, 210029, China.
Objective:
To explore brain perivascular fluid diffusivity dynamics indirectly applying diffusion tensor image analysis along the perivascular space (DTI-ALPS) and to elucidate its relationship between motor and non-motor symptoms in Parkinson's disease with postural instability/gait difficulty (PIGD).
Methods:
105 PD patients (categorized into PIGD and non-PIGD subgroups) and 51 healthy control participants (HCs) received brain MRI examinations with DTI and clinical evaluations. Statistical comparisons of DTI-ALPS indices were performed between groups. Associations involving DTI-ALPS indices, motor scores, cognitive function, and sleep quality were examined using partial correlation and mediation analyses.
Results:
Compared to HCs, PD subgroups exhibited notably reduced left-hemispheric DTI-ALPS index (PIGD: p = 0.006; non-PIGD: p = 0.013). A lower right-hemispheric index was observed exclusively within PIGD group relative to HCs (p = 0.040). With covariates adjusted, left DTI-ALPS index showed inverse association with Unified Parkinson's Disease Rating Scale III (r=-0.347, p = 0.023, p-FDR = 0.046) and PIGD score (r=-0.451, p = 0.002, p-FDR = 0.008), and positive correlation with Frontal Assessment Battery (r = 0.451, p = 0.002, p-FDR = 0.008) scores. After adjustment for education, left ALPS index significantly mediated the association between PIGD score and FAB score, with a significant indirect effect (a*b=-0.140, 95% CI -0.278 to -0.032).
Conclusions:
The results indicate that impaired perivascular diffusivity, is more pronounced in PIGD subtype and is markedly linked to motor symptoms intensity and cognitive abilities. DTI-ALPS index may present a possible neural substrate mediating the interplay between motor/non-motor manifestations in PIGD subtype.
Insights
Impaired brain perivascular fluid diffusivity, measured by Diffusion Tensor Image Analysis along the Perivascular Space (DTI-ALPS), is more pronounced in Parkinson's disease with postural instability/gait difficulty (PIGD). This diffusivity is linked to motor symptoms and cognitive function in PIGD patients.
Area of Science:
- Neuroimaging
- Neurology
- Biomedical Engineering
Background:
- Parkinson's disease (PD) involves motor and non-motor symptoms.
- The PIGD subtype of PD presents unique challenges in gait and balance.
- Perivascular fluid dynamics are crucial for brain health, but their role in PD is not fully understood.
Purpose of the Study:
- To investigate brain perivascular fluid diffusivity using Diffusion Tensor Image Analysis along the Perivascular Space (DTI-ALPS).
- To explore the relationship between DTI-ALPS indices and motor/non-motor symptoms in PD, particularly the PIGD subtype.
Main Methods:
- Brain MRI with DTI was performed on 105 PD patients (PIGD and non-PIGD) and 51 healthy controls (HCs).
- DTI-ALPS indices were compared between groups.
- Associations between DTI-ALPS indices, motor scores (UPDRS III, PIGD score), cognitive function (FAB), and sleep quality were analyzed using partial correlation and mediation analyses.
Main Results:
- PD subgroups showed reduced left-hemispheric DTI-ALPS index compared to HCs.
- The PIGD group exhibited a lower right-hemispheric DTI-ALPS index than HCs.
- Left DTI-ALPS index correlated inversely with motor severity (UPDRS III, PIGD score) and positively with cognitive function (FAB).
- Left ALPS index mediated the relationship between PIGD score and FAB score.
Conclusions:
- Impaired perivascular diffusivity is more pronounced in the PIGD subtype of Parkinson's disease.
- DTI-ALPS indices are significantly associated with motor symptom severity and cognitive abilities in PIGD.
- DTI-ALPS may serve as a neural substrate linking motor and non-motor manifestations in PIGD.
