Perivascular space enlargement accelerates in ageing and Alzheimer’s disease pathology: evidence from a three-year longitudinal multicentre study
Authors: Menze Inga , Bernal Jose , Kaya Pinar , Aki Çağla , Pfister Malte , Geisendörfer Jonas , Yakupov Renat , Coello Roberto Duarte , Valdés-Hernández Maria d. C. , Heneka Michael T. , Brosseron Frederic , Schmid Matthias C. , Glanz Wenzel , Incesoy Enise I. , Butryn Michaela , Rostamzadeh Ayda , Meiberth Dix , Peters Oliver , Preis Lukas , Lammerding Dominik , Gref Daria , Priller Josef , Spruth Eike J. , Altenstein Slawek , Lohse Andrea , Hetzer Stefan , Schneider Anja , Fliessbach Klaus , Kimmich Okka , Vogt Ina R. , Wiltfang Jens , Bartels Claudia , Schott Björn H. , Hansen Niels , Dechent Peter , Buerger Katharina , Janowitz Daniel , Perneczky Robert , Rauchmann Boris-Stephan , Teipel Stefan , Kilimann Ingo , Goerss Doreen , Laske Christoph , Munk Matthias H. , Sanzenbacher Carolin , Hinderer Petra , Scheffler Klaus , Spottke Annika , Roy-Kluth Nina , Lüsebrink Falk , Neumann Katja , Wardlaw Joanna , Jessen Frank , Schreiber Stefanie , Düzel Emrah , Ziegler Gabriel 
Published: October 2024

Abstract
Background
Perivascular space (PVS) enlargement in ageing and Alzheimer’s disease (AD) and the drivers of such a structural change in humans require longitudinal investigation. Elucidating the effects of demographic factors, hypertension, cerebrovascular dysfunction, and AD pathology on PVS dynamics could inform the role of PVS in brain health function as well as the complex pathophysiology of AD.

Methods
We studied PVS in centrum semiovale (CSO) and basal ganglia (BG) computationally over three to four annual visits in 503 participants (255 females; meanage = 70.78 ± 5.78) of the ongoing observational multicentre “DZNE Longitudinal Cognitive Impairment and Dementia Study” (DELCODE) cohort. We analysed data from subjects who were cognitively unimpaired (n = 401), had amnestic mild cognitive impairment (n = 71), or had AD (n = 31). We used linear mixed-effects modelling to test for changes of PVS volumes in relation to cross-sectional and longitudinal age, as well as sex, years of education, hypertension, white matter hyperintensities, AD diagnosis, and cerebrospinal-fluid-derived amyloid (A) and tau (T) status (available for 46.71%; A-T-/A + T-/A + T + n = 143/48/39).

Results
PVS volumes increased significantly over follow-ups (CSO: B = 0.03 [0.02, 0.05], p < 0.001; BG: B = 0.05 [0.03, 0.07], p < 0.001). PVS enlargement rates varied substantially across subjects and depended on the participant’s age, white matter hyperintensities volumes, and amyloid and tau status. PVS volumes were higher across elderly participants, regardless of region of interest (CSO: B = 0.12 [0.02, 0.21], p = 0.017; BG: B = 0.19 [0.09, 0.28], p < 0.001). Faster BG-PVS enlargement related to lower baseline white matter hyperintensities volumes (ρspearman = -0.17, pFDR = 0.001) and was more pronounced in individuals who presented with combined amyloid and tau positivity versus negativity (A + T +  > A-T-, pFDR = 0.004) or who were amyloid positive but tau negative (A + T +  > A + T-, pFDR = 0.07). CSO-PVS volumes increased at a faster rate with amyloid positivity as compared to amyloid negativity (A + T-/A + T +  > A-T-, pFDR = 0.021).

Conclusion
Our longitudinal evidence supports the relevance of PVS enlargement in presumably healthy ageing as well as in AD pathology. We further discuss the region-specific involvement of white matter hyperintensities and neurotoxic waste accumulation in PVS enlargement and the possibility of additional factors contributing to PVS progression. A comprehensive understanding of PVS dynamics could facilitate the understanding of pathological cascades and might inform targeted treatment strategies.

Trial registration
German Clinical Trials Register DRKS00007966. Registered 04.05.2015 – retrospectively registered, https://drks.de/search/en/trial/DRKS00007966.