Impact of Crossing Fibres on Glymphatic Imaging
Author Information
Author(s): Georgiopoulos Charalampos, Werlin Alice, Lasic Samo, Hall Sara, van Westen Danielle, Spotorno Nicola, Hansson Oskar, Nilsson Markus
Primary Institution: Lund University
Hypothesis
The ALPS index would decrease if areas with high levels of crossing fibres are excluded from the measurement.
Conclusion
Crossing fibres significantly inflate the ALPS index, which may explain variability in previous studies on glymphatic function.
Supporting Evidence
- PSP patients had significantly lower conventional ALPS indices compared to healthy controls and PD patients.
- Adjusting for crossing fibres led to less significant differences among diagnostic groups.
- The ALPS index may not be a sensitive indicator of glymphatic function in early stages of neurodegeneration.
Takeaway
This study found that crossing fibres can make it look like the brain's waste clearance system is working better than it actually is, especially in diseases like Parkinson's.
Methodology
A cross-sectional study using diffusion tensor imaging along the perivascular space (DTI-ALPS) to assess glymphatic function in patients with Parkinson's disease, progressive supranuclear palsy, and healthy controls.
Potential Biases
Manual placement of regions of interest (ROIs) could introduce bias, although it was done without knowledge of participants' diagnoses.
Limitations
The relatively small size of the PSP cohort and the lack of age-matching for this group.
Participant Demographics
Participants included 60 with Parkinson's disease (mean age 63.3), 17 with progressive supranuclear palsy (mean age 70.9), and 41 healthy controls (mean age 64.5).
Statistical Information
P-Value
P < 0.001
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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