Purpose
Cerebral amyloid angiopathy (CAA) is defined by amyloid-b deposition in the mediaand adventitia of cortical and leptomeningeal small- tomedium-sized arteries,
arterioles and capillaries.
Recent studies using DWI have detected clinically unsuspectedareas of acute ischaemia in intracerebral haemorrhage,
but the mechanisms underlying these lesions are not clear.Ischaemia could,
for instance,
be due to an active occlusivesmall-vessel arteriopathy.
The aim of this study is to investigate the prevalence and incidence of acute/subacute subclinical ischaemic brainlesions in patients with diagnosis of probable CAA and corticalsuperficial siderosis (cSS) on...
Methods and materials
MRI scans of 65 patients seen at theNational Hospital for Neurology and Neurosurgery,
Queen Square(London),between April 2005 and April 2014,
with a diagnosis of probable CAA,
according to themodified Boston criteria,
and cSS,
were retrospectively analysed.
All images were examined by a radiology resident(E.G.),
blinded to
clinical information,
who analyzed all the scans available for each patient,
starting from the diagnosisand including allthe follow up scans.Acute/subacute small ischaemic lesions (ASIL) were identified as smallcortical/subcorticalhyperintense foci (<5mm)on DWI sequences and with corresponding dark areas on apparentdiffusion...
Results
Of 65 patients with probable CAA,
35 had follow upMRI studies between 4 to 79 months(median 24.2).
Overall ASIL were found in 27 (41.5%) of CAA patients.
15 patients had ASIL at the diagnosis,
9 developed ASIL on follow up scansand 3 showed lesions at the diagnosisand during follow up.
Amongst patients presenting with brain haemorrhage (N=28) 15 had ASIL: 1 close to thehaemorrhage,
11 remote from the haemorrhage (close to cSS or microbleeds),
3 close and remotefrom the haemorrhage.
In patients with nonhaemorrhagicpresentation,
12...
Conclusion
In this study we have demonstrated that subclinical acute/subacute ischaemic brain lesions have a high prevalence in CAApatients.
In CAA,
amyloid-b is deposited in small arteries andarterioles,
causing thickening of the vessel wall and lumen restriction,
and endothelial/vascular smoothmuscle dysfunction.
These changes can notonly cause vessels to become brittle and prone to microaneurysmformation and blood leakage,
but also toimpair local regulation of cerebral blood flow and thus small-vessel
or capillary occlusion.
Our data suggest anintriguing interplay between the haemorrhagic and ischaemiccomponents in small-vessel diseases,suggesting a...
Personal information
Dr Emma Gangemi is a Radiology Resident at the Catholic University of Sacred Heart in Rome.
She enrolled for six months (January 2015-July 2015) in the Clinical Academic Neuroradiology Fellowship Programme at the Lysholm Department of Neuroradiology,
National Hospital for Neurology and Neurosurgery,
Queen Square,
London.
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