Perivascular spaces and brain waste clearance systems: relevance for neurodegenerative and cerebrovascular pathology

Kaylene Gouveia-Freitas,António J Bastos-Leite

doi:10.1007/s00234-021-02718-7

Kaylene Gouveia-Freitas, António J Bastos-Leite

Open Access

https://doi.org/10.1007/s00234-021-02718-7

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Journal: Neuroradiology	Publication Date: May 21, 2021
Citations: 61	License type: open-access

Affiliation: University of Porto

Abstract

Perivascular spaces (PVS) of the brain, often called Virchow-Robin spaces, comprise fluid, cells and connective tissue, and are externally limited by astrocytic endfeet. PVS are involved in clearing brain waste and belong to the “glymphatic” system and/or the “intramural periarterial drainage” pathway through the basement membranes of the arteries. Related brain waste clearance systems include the blood–brain barrier, scavenger cells, cerebrospinal fluid, perineural lymphatic drainage pathways and the newly characterised meningeal lymphatic vessels. Any functional abnormality of PVS or related clearance systems might lead to accumulation of brain waste. It has been postulated that PVS enlargement can be secondary to accumulation of β-amyloid. Lack of integrity of the vascular wall, microbleeds, cerebral amyloid angiopathy (CAA) and enlarged PVS often occur in the preclinical stages of Alzheimer’s disease, preceding substantial brain atrophy. PVS enlargement in the form of état criblé at the basal ganglia has also been considered to reflect focal atrophy, most probably secondary to ischaemic injury, based upon both pathological and imaging arguments. In addition, distinct topographic patterns of enlarged PVS are related to different types of microangiopathy: CAA is linked to enlarged juxtacortical PVS, whereas subjects with vascular risk factors tend to have enlarged PVS in the basal ganglia. Therefore, enlarged PVS are progressively being regarded as a marker of neurodegenerative and cerebrovascular pathology. The present review addresses the evolving concept of PVS and brain waste clearance systems, the potential relevance of their dysfunction to neurodegenerative and cerebrovascular pathology, and potential therapeutic approaches of interest.

Highlights

Perivascular spaces (PVS) of the brain, often called Virchow-Robin spaces, are generally considered to be expansions containing fluid around small vessels
The present review aims at describing the evolving concept of PVS and brain waste clearance systems, possible reasons for dysfunction or enlargement of PVS, and how this dysfunction or enlargement can be associated with—or might play a role in—the progress of several pathological conditions causing cognitive impairment and dementia, such as Alzheimer’s disease (AD), cerebral amyloid angiopathy (CAA) and cerebrovascular pathology
Enlarged PVS are progressively being regarded as a marker of neurodegenerative and cerebrovascular pathology, such as AD and CAA [1, 70, 71]

Summary

Introduction

Perivascular spaces (PVS) of the brain, often called Virchow-Robin spaces, are generally considered to be expansions containing fluid around small vessels. PVS are part of the paravascular way of clearing brain waste [2] and of other recently proposed systems, such as the so-called “glymphatic” system [3], and/or the “intramural periarterial Therapeutic approaches that potentially improve the function of PVS and brain waste clearance systems are described.

Results

Conclusion