{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T18:58:31Z","timestamp":1785351511316,"version":"3.55.0"},"reference-count":96,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T00:00:00Z","timestamp":1785283200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"U. S. Army"},{"DOI":"10.13039\/100000005","name":"Department of Defense","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100000005","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Neurol."],"abstract":"<jats:p>The cholinergic basal forebrain and subcortical gray matter have previously been implicated in Parkinson\u2019s disease (PD), but the relationship between the symptomology of PD, including cognitive impairment, and specific patterns of damage remains unclear. Additionally, understanding the impact of fitness, including motor skills, on brain structure remains a knowledge gap. In this study, we examine a longitudinal cohort of PD patients using advanced microstructural analysis derived from diffusion MRI, alongside volumetric and connectivity components. These imaging metrics are compared to comprehensive cognitive and motor skill fitness metrics. Although the volumetric components well characterize change across the longitudinal timescale, the microstructural analysis was related to a number of composite cognitive scores, including attention, executive function, cognition, language, and the level of motor skill fitness. We further assess the connectivity of the cholinergic basal forebrain, particularly the nucleus basalis of Meynert in area 4 (CH4), and find that connectivity between CH4 and the thalamus is associated with motor skill fitness. The pattern of microstructural results suggests that increased cellularity may support reduced cognitive decline in individuals with PD and greater motor skill fitness.<\/jats:p>","DOI":"10.3389\/fneur.2026.1863964","type":"journal-article","created":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T18:03:26Z","timestamp":1785348206000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Diffusion microstructure alterations in subcortical gray matter are associated with cognitive and motor performance in Parkinson\u2019s disease: a pilot study"],"prefix":"10.3389","volume":"17","author":[{"given":"Benjamin T.","family":"Newman","sequence":"first","affiliation":[{"name":"Department of Psychology, University of Virginia","place":["Charlottesville, VA, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ryan","family":"Foreman","sequence":"additional","affiliation":[{"name":"Department of Neurology, University of Southern California","place":["Los Angeles, CA, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Erin","family":"Donahue","sequence":"additional","affiliation":[{"name":"Department of Neurology, University of Southern California","place":["Los Angeles, CA, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michael W.","family":"Jakowec","sequence":"additional","affiliation":[{"name":"Department of Neurology, University of Southern California","place":["Los Angeles, CA, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrew J.","family":"Petkus","sequence":"additional","affiliation":[{"name":"Department of Neurology, University of Southern California","place":["Los Angeles, CA, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniel P.","family":"Holschneider","sequence":"additional","affiliation":[{"name":"Department of Neurology, University of Southern California","place":["Los Angeles, CA, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joseph","family":"O\u2019Neill","sequence":"additional","affiliation":[{"name":"Division of Child & Adolescent Psychiatry, Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles","place":["Los Angeles, CA, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dawn M.","family":"Schiehser","sequence":"additional","affiliation":[{"name":"Veterans Administration San Diego Healthcare System (VASDHS), San Diego","place":["San Diego, CA, United States"]},{"name":"Department of Psychiatry, University of California, San Diego","place":["San Diego, CA, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Giselle","family":"Petzinger","sequence":"additional","affiliation":[{"name":"Department of Neurology, University of Southern California","place":["Los Angeles, CA, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"John Darrell","family":"Van Horn","sequence":"additional","affiliation":[{"name":"Department of Psychology, University of Virginia","place":["Charlottesville, VA, United States"]},{"name":"School of Data Science, University of Virginia","place":["Charlottesville, VA, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,7,29]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"235","DOI":"10.1016\/S1474-4422(06)70373-8","article-title":"Non-motor symptoms of Parkinson\u2019s disease: diagnosis and management","volume":"5","author":"Chaudhuri","year":"2006","journal-title":"Lancet Neurol"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"318","DOI":"10.1111\/jnc.13691","article-title":"The clinical symptoms of Parkinson\u2019s disease","volume":"139","author":"Sveinbjornsdottir","year":"2016","journal-title":"J Neurochem"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"197","DOI":"10.1016\/S0197-4580(02)00065-9","article-title":"Staging of brain pathology related to sporadic Parkinson\u2019s disease","volume":"24","author":"Braak","year":"2003","journal-title":"Neurobiol Aging"},{"key":"ref4","doi-asserted-by":"crossref","first-page":"932","DOI":"10.1038\/nrn983","article-title":"Pathogenesis of Parkinson\u2019s disease: dopamine, vesicles and \u03b1-synuclein","volume":"3","author":"Lotharius","year":"2002","journal-title":"Nat Rev Neurosci"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"1251","DOI":"10.1136\/jnnp-2019-320450","article-title":"Lower volume, more impairment: reduced cholinergic basal forebrain grey matter density is associated with impaired cognition in Parkinson disease","volume":"90","author":"Barrett","year":"2019","journal-title":"J Neurol Neurosurg Psychiatry"},{"key":"ref6","doi-asserted-by":"publisher","first-page":"27","DOI":"10.1016\/j.parkreldis.2021.07.024","article-title":"Olfaction, cholinergic basal forebrain degeneration, and cognition in early Parkinson disease","volume":"90","author":"Barrett","year":"2021","journal-title":"Parkinsonism Relat Disord"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"e1618","DOI":"10.1212\/WNL.0000000000005421","article-title":"Baseline symptoms and basal forebrain volume predict future psychosis in early Parkinson disease","volume":"90","author":"Barrett","year":"2018","journal-title":"Neurology"},{"key":"ref8","doi-asserted-by":"publisher","first-page":"7","DOI":"10.1016\/j.neuroimage.2015.02.045","article-title":"A multicontrast approach for comprehensive imaging of substantia nigra","volume":"112","author":"Langley","year":"2015","journal-title":"NeuroImage"},{"key":"ref9","doi-asserted-by":"publisher","first-page":"1387","DOI":"10.1007\/s00234-019-02279-w","article-title":"Convolutional neural network-based segmentation can help in assessing the substantia nigra in neuromelanin MRI","volume":"61","author":"Le Berre","year":"2019","journal-title":"Neuroradiology"},{"key":"ref10","doi-asserted-by":"publisher","first-page":"62","DOI":"10.1016\/j.neuroimage.2018.06.049","article-title":"Validation strategies for the interpretation of microstructure imaging using diffusion MRI","volume":"182","author":"Dyrby","year":"2018","journal-title":"NeuroImage"},{"key":"ref11","doi-asserted-by":"publisher","first-page":"2322","DOI":"10.1093\/brain\/awv136","article-title":"Longitudinal changes in free-water within the substantia nigra of Parkinson\u2019s disease","volume":"138","author":"Ofori","year":"2015","journal-title":"Brain"},{"key":"ref12","doi-asserted-by":"publisher","first-page":"e1876","DOI":"10.1212\/WNL.0000000000009363","article-title":"Abnormalities in the white matter tracts in patients with Parkinson disease and psychosis","volume":"94","author":"Lenka","year":"2020","journal-title":"Neurology"},{"key":"ref13","doi-asserted-by":"publisher","first-page":"4","DOI":"10.3389\/fneur.2013.00037","article-title":"White-matter changes correlate with cognitive functioning in Parkinson\u2019s disease","volume":"4","author":"Theilmann","year":"2013","journal-title":"Front Neurol"},{"key":"ref14","doi-asserted-by":"publisher","first-page":"13","DOI":"10.3389\/fnagi.2021.668559","article-title":"Posterior cortical cognitive deficits are associated with structural brain alterations in mild cognitive impairment in Parkinson\u2019s disease","volume":"13","author":"Devignes","year":"2021","journal-title":"Front Aging Neurosci"},{"key":"ref15","doi-asserted-by":"publisher","first-page":"1097","DOI":"10.1016\/j.neurobiolaging.2014.10.029","article-title":"Increased free water in the substantia nigra of Parkinson\u2019s disease: a single-site and multi-site study","volume":"36","author":"Ofori","year":"2015","journal-title":"Neurobiol Aging"},{"key":"ref16","doi-asserted-by":"publisher","first-page":"1081","DOI":"10.1002\/jnr.24430","article-title":"Exercise induces region-specific remodeling of astrocyte morphology and reactive astrocyte gene expression patterns in male mice","volume":"97","author":"Lundquist","year":"2019","journal-title":"J Neurosci Res"},{"key":"ref17","doi-asserted-by":"publisher","first-page":"5291","DOI":"10.1523\/jneurosci.1069-07.2007","article-title":"Effects of treadmill exercise on dopaminergic transmission in the 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine-lesioned mouse model of basal ganglia injury","volume":"27","author":"Petzinger","year":"2007","journal-title":"J Neurosci"},{"key":"ref18","doi-asserted-by":"publisher","first-page":"1212","DOI":"10.1093\/brain\/awac298","article-title":"Mapping astrogliosis in the individual human brain using multidimensional MRI","volume":"146","author":"Benjamini","year":"2023","journal-title":"Brain"},{"key":"ref19","doi-asserted-by":"publisher","first-page":"fcad253","DOI":"10.1093\/braincomms\/fcad253","article-title":"Correspondence of mean apparent propagator MRI metrics with phosphorylated tau and astrogliosis in chronic traumatic encephalopathy","volume":"5","author":"Gangolli","year":"2023","journal-title":"Brain Commun"},{"key":"ref20","first-page":"1061","article-title":"Microglial density alters measures of axonal integrity and structural connectivity","volume":"5","author":"Sue","year":"2020","journal-title":"Biol Psychiatry: Cognit Neurosci Neuroimaging"},{"key":"ref21","doi-asserted-by":"publisher","first-page":"545","DOI":"10.1038\/s41380-022-01580-0","article-title":"In vivo imaging of astrocytes in the whole brain with engineered AAVs and diffusion-weighted magnetic resonance imaging","volume":"29","author":"Li","year":"2024","journal-title":"Mol Psychiatry"},{"key":"ref22","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1001\/archneur.64.1.43","article-title":"Progranulin mutations in primary progressive aphasia: the PPA1 and PPA3 families","volume":"64","author":"Mesulam","year":"2007","journal-title":"Arch Neurol"},{"key":"ref23","doi-asserted-by":"crossref","first-page":"170","DOI":"10.1002\/cne.902140206","article-title":"Cholinergic innervation of cortex by the basal forebrain: cytochemistry and cortical connections of the septal area, diagonal band nuclei, nucleus basalis (substantia innominata), and hypothalamus in the rhesus monkey","volume":"214","author":"Mesulam","year":"1983","journal-title":"J Comp Neurol"},{"key":"ref24","doi-asserted-by":"publisher","first-page":"248","DOI":"10.1016\/j.neuroscience.2014.10.008","article-title":"The place of dopamine in the cortico-basal ganglia circuit","volume":"282","author":"Haber","year":"2014","journal-title":"Neuroscience"},{"key":"ref25","doi-asserted-by":"publisher","first-page":"942","DOI":"10.1016\/j.biocel.2004.09.009","article-title":"Dopaminergic neurons","volume":"37","author":"Chinta","year":"2005","journal-title":"Int J Biochem Cell Biol"},{"key":"ref26","doi-asserted-by":"crossref","first-page":"316","DOI":"10.1002\/cne.903180308","article-title":"Differential cholinergic innervation within functional subdivisions of the human cerebral cortex: a choline acetyltransferase study","volume":"318","author":"Mesulam","year":"1992","journal-title":"J Comp Neurol"},{"key":"ref27","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1002\/cne.902890104","article-title":"Dopaminergic innervation of the basal ganglia in the squirrel monkey as revealed by tyrosine hydroxylase immunohistochemistry","volume":"289","author":"Lavoie","year":"1989","journal-title":"J Comp Neurol"},{"key":"ref28","doi-asserted-by":"crossref","first-page":"254","DOI":"10.1016\/0166-2236(90)90105-J","article-title":"Extrinsic connections of the basal ganglia","volume":"13","author":"Parent","year":"1990","journal-title":"Trends Neurosci"},{"key":"ref29","doi-asserted-by":"crossref","first-page":"461","DOI":"10.1016\/S0079-6123(03)43043-4","article-title":"A new dynamic model of the cortico-basal ganglia loop","volume":"143","author":"Nambu","year":"2004","journal-title":"Prog Brain Res"},{"key":"ref30","doi-asserted-by":"crossref","first-page":"1767","DOI":"10.1093\/brain\/123.9.1767","article-title":"The pedunculopontine nucleus and Parkinson\u2019s disease","volume":"123","author":"Pahapill","year":"2000","journal-title":"Brain"},{"key":"ref31","doi-asserted-by":"publisher","first-page":"2676","DOI":"10.1016\/j.neubiorev.2013.09.003","article-title":"The nucleus basalis of Meynert: a new target for deep brain stimulation in dementia?","volume":"37","author":"Gratwicke","year":"2013","journal-title":"Neurosci Biobehav Rev"},{"key":"ref32","doi-asserted-by":"publisher","first-page":"233","DOI":"10.1111\/jnc.15873","article-title":"Whole-brain neural connectivity to cholinergic neurons in the nucleus basalis of Meynert","volume":"166","author":"Chen","year":"2023","journal-title":"J Neurochem"},{"key":"ref33","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/0304-3940(87)90042-5","article-title":"Cholinergic nucleus basalis neurons may influence the cortex via the thalamus","volume":"74","author":"Levey","year":"1987","journal-title":"Neurosci Lett"},{"key":"ref34","doi-asserted-by":"publisher","first-page":"84","DOI":"10.1038\/s41582-019-0294-x","article-title":"Sex differences in movement disorders","volume":"16","author":"Meoni","year":"2020","journal-title":"Nat Rev Neurol"},{"key":"ref35","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1016\/0022-510X(83)90045-X","article-title":"Pathological changes in the nucleus of Meynert in Alzheimer\u2019s and Parkinson\u2019s diseases","volume":"59","author":"Candy","year":"1983","journal-title":"J Neurol Sci"},{"key":"ref36","doi-asserted-by":"publisher","first-page":"7","DOI":"10.1093\/brain\/awx333","article-title":"Early nucleus basalis of Meynert degeneration predicts cognitive decline in Parkinson\u2019s disease","volume":"141","author":"Gratwicke","year":"2018","journal-title":"Brain"},{"key":"ref37","doi-asserted-by":"publisher","first-page":"2","DOI":"10.1186\/2047-9158-4-2","article-title":"Characteristics of language impairment in Parkinson\u2019s disease and its influencing factors","volume":"4","author":"Liu","year":"2015","journal-title":"Transl Neurodegener"},{"key":"ref38","doi-asserted-by":"publisher","first-page":"4124","DOI":"10.1002\/cne.23415","article-title":"Cholinergic circuitry of the human nucleus basalis and its fate in Alzheimer\u2019s disease","volume":"521","author":"Mesulam","year":"2013","journal-title":"J Comp Neurol"},{"key":"ref39","doi-asserted-by":"publisher","first-page":"67","DOI":"10.1016\/S0079-6123(03)45004-8","article-title":"The cholinergic innervation of the human cerebral cortex","volume":"145","author":"Mesulam","year":"2004","journal-title":"Prog Brain Res"},{"key":"ref40","doi-asserted-by":"publisher","first-page":"695","DOI":"10.1111\/j.1532-5415.2005.53221.x","article-title":"The Montreal cognitive assessment, MoCA: a brief screening tool for mild cognitive impairment","volume":"53","author":"Nasreddine","year":"2005","journal-title":"J Am Geriatr Soc"},{"key":"ref41","first-page":"2501","volume-title":"A recommended scale for cognitive screening in clinical trials of Parkinson\u2019s disease","author":"Chou","year":"2010"},{"key":"ref42","doi-asserted-by":"publisher","first-page":"349","DOI":"10.1002\/mds.24893","article-title":"Diagnostic criteria for mild cognitive impairment in Parkinson\u2019s disease: Movement Disorder Society task force guidelines","volume":"27","author":"Litvan","year":"2012","journal-title":"Mov Disord"},{"key":"ref43","article-title":"Delis-Kaplan executive function system assessment","volume-title":"Assessment","author":"Delis","year":"2001"},{"key":"ref44","doi-asserted-by":"publisher","first-page":"547","DOI":"10.1093\/arclin\/17.6.547","article-title":"The adaptive digit ordering test clinical application, reliability, and validity of a verbal working memory test","volume":"17","author":"Werheid","year":"2002","journal-title":"Arch Clin Neuropsychol"},{"key":"ref45","article-title":"Boston naming test the clinical neuropsychologist","author":"Kaplan","year":"2001"},{"key":"ref46","article-title":"California verbal learning test","author":"Delis","year":"2000","journal-title":"Assessment (N Y)"},{"key":"ref47","volume-title":"Brief Visuospatial Memory Test--Revised","author":"Benedict","year":"1997"},{"key":"ref48","article-title":"Judgment of line orientation","volume-title":"APA PsycTests","author":"Benton","year":"1983"},{"key":"ref49","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1037\/0022-006X.49.1.15","article-title":"A validity study of the Hooper visual organization test","volume":"49","author":"Boyd","year":"1981","journal-title":"J Consult Clin Psychol"},{"key":"ref50","volume-title":"Wisconsin Card Sorting Test\u201464 Card Version Professional Manual","author":"Kong","year":"2000"},{"key":"ref51","doi-asserted-by":"publisher","first-page":"2129","DOI":"10.1002\/mds.22340","article-title":"Movement Disorder Society-sponsored revision of the unified Parkinson\u2019s disease rating scale (MDS-UPDRS): scale presentation and clinimetric testing results","volume":"23","author":"Goetz","year":"2008","journal-title":"Mov Disord"},{"key":"ref52","doi-asserted-by":"publisher","first-page":"189","DOI":"10.1055\/s-0041-1725133","article-title":"Evidence for early and regular physical therapy and exercise in Parkinson\u2019s disease","volume":"41","author":"Ellis","year":"2021","journal-title":"Semin Neurol"},{"key":"ref53","doi-asserted-by":"crossref","first-page":"1105","DOI":"10.1111\/j.1532-5415.1990.tb01373.x","article-title":"An objective measure of physical function of elderly outpatients: the physical performance test","volume":"38","author":"Reuben","year":"1990","journal-title":"J American Geriatrics Society"},{"key":"ref54","doi-asserted-by":"crossref","first-page":"M85","DOI":"10.1093\/geronj\/49.2.M85","article-title":"A short physical performance battery assessing lower extremity function: association with self-reported disability and prediction of mortality and nursing home admission","volume":"49","author":"Guralnik","year":"1994","journal-title":"J Gerontol"},{"key":"ref55","doi-asserted-by":"crossref","first-page":"142","DOI":"10.1111\/j.1532-5415.1991.tb01616.x","article-title":"The timed \u201cUp & Go\u201d: a test of basic functional mobility for frail elderly persons","volume":"39","author":"Podsiadlo","year":"1991","journal-title":"Journal of the American geriatrics Society,"},{"key":"ref56","doi-asserted-by":"publisher","first-page":"365","DOI":"10.1159\/000146787","article-title":"A new simple performance test focused on agility in elderly people: the ten step test","volume":"54","author":"Miyamoto","year":"2008","journal-title":"Gerontology"},{"key":"ref57","doi-asserted-by":"publisher","first-page":"100370","DOI":"10.1016\/j.prdoa.2025.100370","article-title":"Longitudinal associations between physical performance and cognition in individuals with Parkinson\u2019s disease","volume":"13","author":"Petkus","year":"2025","journal-title":"Clinical Parkinsonism & Related Disorders"},{"key":"ref58","doi-asserted-by":"publisher","first-page":"2161","DOI":"10.1002\/mrm.28242","article-title":"Test\u2013retest reliability and long-term stability of three-tissue constrained spherical deconvolution methods for analyzing diffusion MRI data","volume":"84","author":"Newman","year":"2020","journal-title":"Magn Reson Med"},{"key":"ref59","doi-asserted-by":"publisher","first-page":"e0301964","DOI":"10.1371\/journal.pone.0301964","article-title":"Conduction velocity, G-ratio, and extracellular water as microstructural characteristics of autism spectrum disorder","volume":"19","author":"Newman","year":"2024","journal-title":"PLoS One"},{"key":"ref60","doi-asserted-by":"publisher","first-page":"101301","DOI":"10.1016\/j.dcn.2023.101301","article-title":"An intracellular isotropic diffusion signal is positively associated with pubertal development in white matter","volume":"63","author":"Newman","year":"2023","journal-title":"Dev Cogn Neurosci"},{"key":"ref61","doi-asserted-by":"publisher","first-page":"774","DOI":"10.1016\/j.neuroimage.2012.01.021","article-title":"FreeSurfer","volume":"62","author":"Fischl","year":"2012","journal-title":"NeuroImage"},{"key":"ref62","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1016\/j.neuroimage.2010.06.010","article-title":"Automatic parcellation of human cortical gyri and sulci using standard anatomical nomenclature","volume":"53","author":"Destrieux","year":"2010","journal-title":"NeuroImage"},{"key":"ref63","doi-asserted-by":"publisher","first-page":"394","DOI":"10.1016\/j.neuroimage.2016.08.016","article-title":"Denoising of diffusion MRI using random matrix theory","volume":"142","author":"Veraart","year":"2016","journal-title":"NeuroImage"},{"key":"ref64","doi-asserted-by":"publisher","first-page":"1574","DOI":"10.1002\/mrm.26054","article-title":"Gibbs-ringing artifact removal based on local subvoxel-shifts","volume":"76","author":"Kellner","year":"2016","journal-title":"Magn Reson Med"},{"key":"ref65","doi-asserted-by":"publisher","first-page":"1063","DOI":"10.1016\/j.neuroimage.2015.10.019","article-title":"An integrated approach to correction for off-resonance effects and subject movement in diffusion MR imaging","volume":"125","author":"Andersson","year":"2016","journal-title":"NeuroImage"},{"key":"ref66","doi-asserted-by":"publisher","first-page":"556","DOI":"10.1016\/j.neuroimage.2016.06.058","article-title":"Incorporating outlier detection and replacement into a non-parametric framework for movement and distortion correction of diffusion MR images","volume":"141","author":"Andersson","year":"2016","journal-title":"NeuroImage"},{"key":"ref67","doi-asserted-by":"publisher","first-page":"870","DOI":"10.1016\/S1053-8119(03)00336-7","article-title":"How to correct susceptibility distortions in spin-echo echo-planar images: application to diffusion tensor imaging","volume":"20","author":"Andersson","year":"2003","journal-title":"NeuroImage"},{"key":"ref68","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1093\/comjnl\/bxm075","article-title":"Super-resolution in medical imaging","volume":"52","author":"Greenspan","year":"2009","journal-title":"Comput J"},{"key":"ref69","first-page":"3010","article-title":"A novel iterative approach to reap the benefits of multi-tissue CSD from just single-shell (+ b= 0) diffusion MRI data","volume":"24","author":"Dhollander","year":"2016","journal-title":"Proc ISMRM"},{"key":"ref70","first-page":"1815","article-title":"Towards interpretation of 3-tissue constrained spherical deconvolution results in pathology","volume":"25","author":"Dhollander","year":"2017","journal-title":"Proc Intl Soc Mag Reson Med"},{"key":"ref71","doi-asserted-by":"publisher","first-page":"102479","DOI":"10.1016\/j.nicl.2020.102479","article-title":"In vivo microstructural heterogeneity of white matter lesions in healthy elderly and Alzheimer\u2019s disease participants using tissue compositional analysis of diffusion MRI data","volume":"28","author":"Mito","year":"2020","journal-title":"NeuroImage: Clinical"},{"key":"ref72","first-page":"135","article-title":"Investigating microstructural heterogeneity of white matter hyperintensities in Alzheimer\u2019s disease using single-shell 3-tissue constrained spherical deconvolution","author":"Mito","year":"2018","journal-title":"Proc Intl Soc Mag Reson Med"},{"key":"ref73","doi-asserted-by":"publisher","first-page":"119168","DOI":"10.1016\/j.neuroimage.2022.119168","article-title":"Brain tissue microstructural and free-water composition 13 years after very preterm birth","volume":"254","author":"Kelly","year":"2022","journal-title":"NeuroImage"},{"key":"ref74","doi-asserted-by":"publisher","first-page":"3976","DOI":"10.1016\/j.neuroimage.2011.10.045","article-title":"Apparent fibre density: a novel measure for the analysis of diffusion-weighted magnetic resonance images","volume":"59","author":"Raffelt","year":"2012","journal-title":"NeuroImage"},{"key":"ref75","doi-asserted-by":"publisher","first-page":"3528","DOI":"10.1002\/hbm.22860","article-title":"NTU-DSI-122: a diffusion spectrum imaging template with high anatomical matching to the ICBM-152 space","volume":"36","author":"Hsu","year":"2015","journal-title":"Hum Brain Mapp"},{"key":"ref76","volume-title":"Proceedings of the ISMRM 28th General Meeting","author":"Newman","year":"2020"},{"key":"ref77","doi-asserted-by":"publisher","first-page":"58","DOI":"10.1016\/j.neuroimage.2016.09.029","article-title":"Investigating white matter fibre density and morphology using fixel-based analysis","volume":"144","author":"Raffelt","year":"2017","journal-title":"NeuroImage"},{"key":"ref78","doi-asserted-by":"publisher","first-page":"119612","DOI":"10.1016\/j.neuroimage.2022.119612","article-title":"Micapipe: A pipeline for multimodal neuroimaging and connectome analysis","volume":"263","author":"Cruces","year":"2022","journal-title":"NeuroImage"},{"key":"ref79","first-page":"1","article-title":"Advanced normalization tools (ANTS)","volume":"2","author":"Avants","year":"2009","journal-title":"Insight j"},{"key":"ref80","doi-asserted-by":"publisher","first-page":"1112","DOI":"10.1016\/j.neuroimage.2010.08.068","article-title":"Bound pool fractions complement diffusion measures to describe white matter micro and macrostructure","volume":"54","author":"Stikov","year":"2011","journal-title":"NeuroImage"},{"key":"ref81","doi-asserted-by":"publisher","first-page":"397","DOI":"10.1016\/j.neuroimage.2015.05.023","article-title":"In vivo histology of the myelin g-ratio with magnetic resonance imaging","volume":"118","author":"Stikov","year":"2015","journal-title":"NeuroImage"},{"key":"ref82","doi-asserted-by":"publisher","first-page":"80","DOI":"10.1016\/j.neuroimage.2017.08.038","article-title":"Promise and pitfalls of g-ratio estimation with MRI","volume":"182","author":"Campbell","year":"2018","journal-title":"NeuroImage"},{"key":"ref83","doi-asserted-by":"publisher","first-page":"108990","DOI":"10.1016\/j.jneumeth.2020.108990","article-title":"Towards in vivo g-ratio mapping using MRI: unifying myelin and diffusion imaging","volume":"348","author":"Mohammadi","year":"2021","journal-title":"J Neurosci Methods"},{"key":"ref84","doi-asserted-by":"publisher","first-page":"101","DOI":"10.1113\/jphysiol.1951.sp004655","article-title":"A theory of the effects of fibre size in medullated nerve","volume":"115","author":"Rushton","year":"1951","journal-title":"J Physiol"},{"key":"ref85","doi-asserted-by":"publisher","first-page":"128","DOI":"10.1016\/j.neuroimage.2019.03.025","article-title":"Modeling conduction delays in the corpus callosum using MRI-measured g-ratio","volume":"195","author":"Berman","year":"2019","journal-title":"NeuroImage"},{"key":"ref86","doi-asserted-by":"publisher","first-page":"116137","DOI":"10.1016\/j.neuroimage.2019.116137","article-title":"MRtrix3: a fast, flexible and open software framework for medical image processing and visualisation","volume":"202","author":"Tournier","year":"2019","journal-title":"NeuroImage"},{"key":"ref87","doi-asserted-by":"publisher","first-page":"298","DOI":"10.1016\/j.neuroimage.2012.11.049","article-title":"SIFT: spherical-deconvolution informed filtering of tractograms","volume":"67","author":"Smith","year":"2013","journal-title":"NeuroImage"},{"key":"ref88","doi-asserted-by":"publisher","first-page":"57","DOI":"10.1007\/s11682-023-00811-4","article-title":"Increased perivascular space volume in white matter and basal ganglia is associated with cognition in Parkinson\u2019s disease","volume":"18","author":"Donahue","year":"2023","journal-title":"Brain Imaging Behav"},{"key":"ref89","doi-asserted-by":"publisher","first-page":"1126","DOI":"10.1002\/mds.28473","article-title":"Global and regional changes in perivascular space in idiopathic and familial Parkinson\u2019s disease","volume":"36","author":"Donahue","year":"2021","journal-title":"Mov Disord"},{"key":"ref90","doi-asserted-by":"publisher","first-page":"101985","DOI":"10.1016\/j.nicl.2019.101985","article-title":"Free-water imaging of the hippocampus is a sensitive marker of Alzheimer\u2019s disease","volume":"24","author":"Ofori","year":"2019","journal-title":"NeuroImage: Clinical"},{"key":"ref91","author":"Blair","year":"2019"},{"key":"ref92","author":"Newman","year":"2022"},{"key":"ref93","doi-asserted-by":"publisher","first-page":"1245","DOI":"10.3390\/brainsci15111245","article-title":"Functional and structural connectivity correlates of axial symptom outcomes after Pallidal deep brain stimulation in Parkinson\u2019s disease","volume":"15","author":"Perez Rodriguez Garcia","year":"2025","journal-title":"Brain Sci"},{"key":"ref94","doi-asserted-by":"publisher","first-page":"98","DOI":"10.1016\/j.nicl.2017.07.011","article-title":"Diffusion tensor imaging in Parkinson\u2019s disease: review and meta-analysis","volume":"16","author":"Atkinson-Clement","year":"2017","journal-title":"Neuroimage: Clinical"},{"key":"ref95","doi-asserted-by":"publisher","first-page":"104","DOI":"10.1016\/j.neuroimage.2017.11.024","article-title":"Harmonization of cortical thickness measurements across scanners and sites","volume":"167","author":"Fortin","year":"2018","journal-title":"NeuroImage"},{"key":"ref96","doi-asserted-by":"publisher","first-page":"151","DOI":"10.1038\/s41531-024-00758-3","article-title":"A worldwide study of white matter microstructural alterations in people living with Parkinson\u2019s disease","volume":"10","author":"Owens-Walton","year":"2024","journal-title":"npj Parkinsons Dis"}],"container-title":["Frontiers in Neurology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fneur.2026.1863964\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T18:03:32Z","timestamp":1785348212000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fneur.2026.1863964\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,29]]},"references-count":96,"alternative-id":["10.3389\/fneur.2026.1863964"],"URL":"https:\/\/doi.org\/10.3389\/fneur.2026.1863964","relation":{},"ISSN":["1664-2295"],"issn-type":[{"value":"1664-2295","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,29]]},"article-number":"1863964"}}