Reassessment of the DTI-ALPS index in focal epilepsy.
13 affiliations
- 1Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.
- 2Department of Neurosurgery, Medical University of Vienna, Vienna, Austria.
- 3Christian Doppler Laboratory for MR Imaging Biomarkers, Medical University of Vienna, Vienna, Austria.
- 4Comprehensive Center for Clinical Neurosciences & Mental Health, Medical University of Vienna, Vienna, Austria.
- 5Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy.
- 6Department of Radiology and Nuclear Medicine, Amsterdam UMC, Vrije Universiteit, Amsterdam, Netherlands.
- 7Department of Neurology, Medical University of Vienna, Vienna, Austria.
- 8UCL Queen Square Institute of Neurology, University College London, London, UK.
- 9UCL Hawkes Institute, Department of Medical Physics and Biomedical Engineering, University College London, London, UK.
- 10Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria. [email protected].
- 11Comprehensive Center for Clinical Neurosciences & Mental Health, Medical University of Vienna, Vienna, Austria. [email protected].
- 12UCL Queen Square Institute of Neurology, University College London, London, UK. [email protected].
- 13Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden. [email protected].
Abstract
Objective
Recent evidence highlights the limited specificity of diffusion tensor imaging (DTI) along perivascular spaces (ALPS) as a noninvasive glymphatic biomarker because microstructural tract degeneration and crossing-fiber geometry confound it. We aimed to reassess the interpretation of the DTI-ALPS index in people with focal epilepsy.Materials and methods
Seventy-nine people with drug-resistant focal epilepsy (PWFE) underwent comprehensive presurgical work-up and 3-T magnetic resonance imaging (MRI). Etiologies included MRI-negative epilepsy, malformations of cortical development, temporal lobe epilepsy, and low-grade epilepsy-associated tumors. DTI preprocessing was conducted using QSIPrep with automated region-of-interest (ROI) placement. Linear regression models and Wilcoxon signed-rank tests were used to assess group differences and associations with clinical variables. Twenty-five age- and sex-matched healthy controls were included for comparison.Results
Seventy-nine patients (28.6 years ± 11.3 [mean ± standard deviation]; 47 men, 32 women) and 25 healthy controls (mean age, 26.7 years ± 4.2; 11 men, 14 women) were evaluated. DTI-ALPS findings were more abnormal in lesions in proximity to the ROI (p = 0.014), implicating local white matter disruption as a modifier, which was further corroborated by reduced postoperative values. No associations were identified with disease duration, sex, or normalized gray-or white matter volumes.Conclusion
Our results demonstrate a distance-dependent correlation of DTI-ALPS values to the seizure onset zone in focal epilepsy, whilst no significant associations to disease duration or normalized brain volumes were found. Together, these findings suggest that local disruption of fiber tracts may act as important modifiers of this measure and warrant caution in the interpretation of the DTI-ALPS index.Key points
Question Microstructural changes may significantly confound the interpretation of the DTI-ALPS index as a surrogate parameter for glymphatic system dysfunction in epilepsy. Findings No significant differences in the DTI-ALPS index were observed comparing PWFE with healthy controls; however, lesion proximity and post-operative status significantly alter the metric. Relevance statement Local white-matter disruption and microstructural architecture may significantly alter the DTI-ALPS index; therefore, caution is warranted when interpreting the index as a glymphatic biomarker in focal epilepsy.
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BibTeX
@article{chambers2026reassessment,
title = {{Reassessment of the DTI-ALPS index in focal epilepsy.}},
author = {Stefanie Chambers and Leo Hofer and Mario Tranfa and Patric Kienast and Julia Shawarba and Radheshyam Stepponat and Judith Jud and Susanne Aull-Watschinger and Ekaterina Pataraia and Florian Ph S Fischmeister and Frederik Barkhof and Gilbert Hangel and Karl Rössler and Giuseppe Pontillo and Gregor Kasprian and Lukas Haider},
journal = {European radiology experimental},
year = {2026},
month = oct,
doi = {10.1186/s41747-026-00799-8},
url = {https://europepmc.org/article/MED/42909784},
note = {CC BY},
}
RIS
TY - JOUR
TI - Reassessment of the DTI-ALPS index in focal epilepsy.
AU - Stefanie Chambers
AU - Leo Hofer
AU - Mario Tranfa
AU - Patric Kienast
AU - Julia Shawarba
AU - Radheshyam Stepponat
AU - Judith Jud
AU - Susanne Aull-Watschinger
AU - Ekaterina Pataraia
AU - Florian Ph S Fischmeister
AU - Frederik Barkhof
AU - Gilbert Hangel
AU - Karl Rössler
AU - Giuseppe Pontillo
AU - Gregor Kasprian
AU - Lukas Haider
PY - 2026
DA - 2026/10/23
JO - European radiology experimental
DO - 10.1186/s41747-026-00799-8
UR - https://europepmc.org/article/MED/42909784
AB - Objective Recent evidence highlights the limited specificity of diffusion tensor imaging (DTI) along perivascular spaces (ALPS) as a noninvasive glymphatic biomarker because microstructural tract degeneration and crossing-fiber geometry confound it. We aimed to reassess the interpretation of the DTI-ALPS index in people with focal epilepsy.Materials and methods Seventy-nine people with drug-resistant focal epilepsy (PWFE) underwent comprehensive presurgical work-up and 3-T magnetic resonance imaging (MRI). Etiologies included MRI-negative epilepsy, malformations of cortical development, temporal lobe epilepsy, and low-grade epilepsy-associated tumors. DTI preprocessing was conducted using QSIPrep with automated region-of-interest (ROI) placement. Linear regression models and Wilcoxon signed-rank tests were used to assess group differences and associations with clinical variables. Twenty-five age- and sex-matched healthy controls were included for comparison.Results Seventy-nine patients (28.6 years ± 11.3 [mean ± standard deviation]; 47 men, 32 women) and 25 healthy controls (mean age, 26.7 years ± 4.2; 11 men, 14 women) were evaluated. DTI-ALPS findings were more abnormal in lesions in proximity to the ROI (p = 0.014), implicating local white matter disruption as a modifier, which was further corroborated by reduced postoperative values. No associations were identified with disease duration, sex, or normalized gray-or white matter volumes.Conclusion Our results demonstrate a distance-dependent correlation of DTI-ALPS values to the seizure onset zone in focal epilepsy, whilst no significant associations to disease duration or normalized brain volumes were found. Together, these findings suggest that local disruption of fiber tracts may act as important modifiers of this measure and warrant caution in the interpretation of the DTI-ALPS index.Key points Question Microstructural changes may significantly confound the interpretation of the DTI-ALPS index as a surrogate parameter for glymphatic system dysfunction in epilepsy. Findings No significant differences in the DTI-ALPS index were observed comparing PWFE with healthy controls; however, lesion proximity and post-operative status significantly alter the metric. Relevance statement Local white-matter disruption and microstructural architecture may significantly alter the DTI-ALPS index; therefore, caution is warranted when interpreting the index as a glymphatic biomarker in focal epilepsy.
SN - 2509-9280
ER -