<p class="first" id="P3">Recent reports describing lymphatic vasculature in the meninges
have challenged the
traditional understanding of interstitial solute clearance from the central nervous
system, although the significance of this finding in human neurological disease remains
unclear. To begin to define the role of meningeal lymphatic function in the clearance
of interstitial amyloid beta (Aβ), and the contribution that its failure may make
to the development of Alzheimer’s disease (AD), we examined meningeal tissue from
a case series including AD and control subjects by confocal microscopy. Our findings
confirm the presence of lymphatic vasculature in the human meninges and indicate that,
unlike perivascular efflux pathways in the brain parenchyma in subjects with AD, Aβ
is not deposited in or around meningeal lymphatic vessels associated with dural sinuses.
Our findings demonstrate that while the meningeal lymphatic vasculature may serve
as an efflux route for Aβ from the brain and cerebrospinal fluid, Aβ does not deposit
in the walls of meningeal lymphatic vessels in the setting of AD.