Fatal Outcome of Intravenous Thrombolysis With an Unexpected Finding of Amyloid-β-Related Angiitis-A Case Report Highlighting a Relevant Scenario With Acute Focal Neurological Deficits and Minimal Radiological Presentation.

Cerebral amyloid angiopathy (CAA) has been implicated as a risk for developing lobar intracerebral hemorrhage (ICH) after intravenous thrombolysis (IVT) applied for acute ischemic stroke (AIS). However, there is a paucity of cases reported with histopathological CAA diagnosis in this setting, with a single report to imply the role of CAA-related inflammation (CAA-RI). We report clinical, radiological, and neuropathological observations of a 65-year-old woman who presented with acute left-hemispheric symptoms with an initially unrevealing cranial computed tomography (CT) and received IVT for presumed AIS. The course was rapidly complicated by a huge lobar ICH and a fatal outcome. The autopsy revealed severe CAA, unexpectedly with transmural CAA-RI, a.k.a. amyloid-β-related angiitis (ABRA), and histopathological evidence for vascular amyloid-β phagocytosis. Re-evaluation of initial imaging did not reveal signs of asymmetric confluent white matter edema characteristic of CAA-RI, but raised the suspicion of a tiny left central convexity subarachnoid hemorrhage, a substrate of amyloid spells. The genotype of the apolipoprotein E (ApoE) gene (ApoE) was ε3/ε3. Being the second published thrombolysis-associated fatality with ABRA and among the few with definite CAA, the present case confirms CAA/CAA-RI to be a potential hidden risk for IVT-associated ICHs, urging for awareness of CAA-associated pathologies and clinical-radiological hints in an AIS setting. The findings implicate the relevance of vascular Aβ phagocytosis in the pathogenesis, confirm that CAA-RI may present without prominent edema, highlight that CAA/CAA-RI-related focal neurological deficits (including amyloid spells) can be potential AIS mimics within the IVT time window, and urge for rigorous analysis of pre-IVT CT scans for even subtle sulcal hyperdensities suggesting cSAH/amyloid spell in elderly patients, prompting consideration of magnetic resonance imaging.