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Updated: Jul 10, 2026
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Independent prognostic value of peak width of skeletonized mean diffusivity on clinical progression in Alzheimer's
Jonas Alexander Jarholm1,2, Sandra Tecelão1, Bjørn-Eivind Kirsebom1,3,4
1Department of Neurology Akershus University Hospital Lørenskog Norway.
Introduction:
Peak width of skeletonized mean diffusivity (PSMD) is a candidate magnetic resonance imaging marker for global white matter integrity. We investigated the value of PSMD in predicting clinical progression in amyloid-positive and amyloid-negative individuals.
Methods:
PSMD, cognition, and amyloid status were measured in 254 subjects from the Dementia Disease Initiation (DDI) cohort and 211 subjects from the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort. Survival analysis was conducted on 166 DDI subjects and validated in 178 ADNI subjects using Clinical Dementia Rating scale.
Results:
High PSMD amyloid-positive individuals had an increased risk of clinical progression relative to those with low PSMD, driven by independent additive effects of amyloid pathology and PSMD. Higher PSMD was predominantly associated with slower processing speed and reduced executive function, but not with memory performance.
Discussion:
Combining PSMD with amyloid status may improve the prediction of clinical progression in Alzheimer's disease, particularly in relation to executive and processing speed domains.
Insights
Peak width of skeletonized mean diffusivity (PSMD) combined with amyloid status predicts Alzheimer's disease progression. High PSMD in amyloid-positive individuals indicates increased risk, particularly affecting processing speed and executive function.
Area of Science:
- Neuroimaging
- Biomarkers
- Alzheimer's Disease Research
Background:
- Peak width of skeletonized mean diffusivity (PSMD) is a potential magnetic resonance imaging (MRI) marker for assessing global white matter integrity.
- Investigating PSMD's predictive value for clinical progression in individuals with and without amyloid pathology is crucial for understanding Alzheimer's disease (AD) development.
Purpose of the Study:
- To evaluate the utility of PSMD in predicting clinical progression in both amyloid-positive and amyloid-negative individuals.
- To determine the association of PSMD with cognitive domains, specifically processing speed, executive function, and memory.
Main Methods:
- PSMD, cognitive function, and amyloid status were assessed in participants from the Dementia Disease Initiation (DDI) and Alzheimer's Disease Neuroimaging Initiative (ADNI) cohorts.
- Survival analysis was performed on DDI subjects and validated in ADNI subjects using the Clinical Dementia Rating scale to predict clinical progression.
Main Results:
- High PSMD in amyloid-positive individuals was associated with an increased risk of clinical progression, indicating additive effects of amyloid pathology and PSMD.
- Elevated PSMD levels were primarily linked to slower processing speed and diminished executive function, but not significantly with memory performance.
Conclusions:
- The combination of PSMD and amyloid status may enhance the prediction of clinical progression in Alzheimer's disease.
- This combined approach shows particular promise for predicting changes in executive function and processing speed domains.
