Cerebral amyloid angiopathy: a transient ischaemic attack mimic

Abstract

Cerebral amyloid angiopathy: a transient ischaemic attack mimicCerebral amyloid angiopathy is a commonly occurring condition that is not familiar to most clinicians. A common presenting feature may be transient focal neurological symptoms leading to the potential for clinical misdiagnosis as transient ischaemic attack. This may result in the inappropriate use of anti-platelets and anticoagulants or radiological misdiagnosis. It is also being increasingly recognised as an important cause of spontaneous intracerebral haemorrhage and cognitive impairment in the elderly. Cerebral amyloid angiopathy can be diagnosed based on clinical and radiological fi ndings, but clinicians need a high index of suspicion to ensure appropriate investigations are requested. In this article we aim to cover the pathophysiology, clinical fi ndings, radiological appearances and approach to management of cerebral amyloid angiopathy. KEYWORDS:Cerebral amyloid angiopathy, convexity subarachnoid haemorrhage, cerebral microbleeds IntroductionCerebral amyloid angiopathy (CAA) is being increasingly recognised as an important cause of spontaneous intracerebral haemorrhage (ICH) and cognitive impairment in elderly people. Despite this, it is not a diagnosis familiar to most physicians. The presenting complaint may include transient focal neurological symptoms, leading to misdiagnosis as a transient ischaemic attack (TIA), and subsequent inappropriate anticoagulation or anti-platelet therapy. In this paper the authors aim to cover the basic pathophysiology of CAA, and the clinical fi ndings, radiological appearances and approach to management. PathophysiologyCerebral amyloid angiopathy (CAA) is characterised by progressive deposition of amyloid-β in the wall of smallto medium-sized blood vessels in the cerebral cortex and leptomeninges. 1 It favours posterior cortical regions, followed by frontal temporal and parietal lobes.2 CAA can also affect cerebellar vessels, but only rarely those in the brain stem or basal ganglia. 2 Initially it was thought to be a rarity but recently has been increasingly found to be an important cause of spontaneous ICH, a condition for which very few effective interventions have been identifi ed. A better understanding of CAA may lead to improved clinical management and future therapeutic options.Amyloid-β is initially deposited in the tunica media, smoot h muscle cells and adventitia. 1 As disease progresses, smooth muscle cells are lost, the outer part of the tunica media detaches and fi brinoid necrosis and microaneurysms develop. 2 Microbleeding may then occur and blood breakdown products are deposited around the blood vessels. 3 CAA is also associated with cortical microinfarcts, ischaemic demyelination and gliosis. 3 Based on pathological fi ndings CAA has been split into type 1 and type 2. 4 In CAA type 1 the amyloid-β is seen in cortical capillaries, as well as other vessels. 4 In CAA type 2 the amyloid-β is seen in leptomeningeal and cortical arteries, arterioles and veins only. 4 Clinically this is important b...

Microcirculation of the brain: morphological assessment in degenerative diseases and restoration processes

“…Such small hemorrhages are accompanied by an accumulation of Aβ depositions in the tunica media, smooth muscle cells, and adventitia (Charidimou et al, 2012;Brown and Thore 2011). Clinically, pathological changes in vessels in the AD are manifested as cerebral amyloid angiitis (Chung et al, 2011) or more frequently as cerebral amyloid angiopathy (Charidimou et al, 2012;Illsley and Ramadan, 2014), which are responsible for 5-10% of spontaneous intracerebral hemorrhage (Vinters, 1987). Sengillo et al (2013) demonstrated a significant decrease in the number of pericytes and mural vascular cells in the human cortex and hippocampus by 60% and 33%, respectively.…”

Prevalence of cerebral amyloid angiopathy: A systematic review and meta‐analysis

“… 7 , 38 Avoiding misdiagnosis is crucial, as the administration of anti‐platelet medication and anticoagulants for transient ischemic attacks may increase the risk of CAA‐related ICH. 39 …”

Cerebral amyloid angiopathy with related inflammation masquerading as crescendo transient ischaemic attacks

“…Case reports have discussed amyloid spells as seen here, which are often confused as ischaemic events or focal seizures 2 3. The cause of amyloid spells remains unknown but they probably represent either focal seizures due to cerebral irritation from intracerebral haemorrhage, a vasospastic phenomenon or a cortical spreading depression, as in migraine 4…”

“…CAA-related inflammation (CAA-RI) is a recently recognised subtype of CAA in which there is neuropathological evidence of CAA-associated vascular inflammation 1. CAA and its inflammatory forms are associated with transient focal events; typically stereotyped migratory sensory-predominant symptoms, often referred to as ‘amyloid spells’ 2–4. We describe a 63-year-old man presenting with what was thought to be capsular warning syndrome, but later diagnosed with CAA-RI, and detail the diagnostic challenge that CAA-RI poses to clinicians as an under-recognised stroke mimic.…”