MRI Showing White Matter Lesions and Multiple Lobar Microbleeds in a Patient with Reversible Encephalopathy

Cerebral Amyloid Angiopathy-Related Inflammation: A Single-Center Experience and a Literature Review

Background: Limited data exist regarding the prevalence of clinical, neuroimaging, and genetic markers among patients diagnosed with Cerebral Amyloid Angiopathy−related inflammation (CAA-ri). We sought to determine these characteristics in patients diagnosed in our center and to summarize available literature published either as single-case reports or small case series (<5 patients). Methods: We reported our single-center experience of patients diagnosed with CAA-ri according to international criteria during a seven-year period (2015−2022), and we abstracted data from 90 previously published cases. Results: Seven patients (43% women, mean age 70 ± 13 years) were diagnosed with CAA-ri in our center. The most common symptom at presentation was focal neurological dysfunction (71%), and the most prevalent radiological finding was the presence of T2/FLAIR white matter hyperintensities (100%). All patients were treated with corticosteroids and had a favorable functional outcome. Among 90 previously published CAA-ri cases (51% women, mean age 70 ± 9 years), focal neurological dysfunction was the most common symptom (76%), followed by a cognitive decline (46%) and headache (34%). The most prevalent neuroimaging findings were cerebral microbleeds (85%), asymmetric T2/FLAIR white matter hyperintensities (81%), and gadolinium-enhancing T1-lesions (37%). Genetic testing for the Apolipoprotein-E gene was available in 27 cases; 59% carried the APOE ε4/ε4 genotype. The majority of the published CAA-ri cases (78%) received corticosteroid monotherapy, while 17 patients (19%) were treated with additional immunosuppressive treatment. Favorable functional outcome following treatment was documented in 70% of patients. Conclusion: Improving the vigilance of clinicians regarding the early recognition and accurate diagnosis of CAA-ri is crucial for swift therapy initiation, which may result in improved functional outcomes.

Silent arteriovenous malformation hemorrhage and the recognition of "unruptured" arteriovenous malformation patients who benefit from surgical intervention

BACKGROUND

Arteriovenous malformation (AVM) patients present in 4 ways relative to hemorrhage: (1) unruptured, without a history or radiographic evidence of old hemorrhage (EOOH); (2) silent hemorrhage, without a bleeding history but with EOOH; (3) ruptured, with acute bleeding but without EOOH; and (4) reruptured, with acute bleeding and EOOH.

OBJECTIVE

We hypothesized that characteristics and outcomes in the unrecognized group of silent hemorrhage patients may differ from those of unruptured patients.

METHODS

Two hundred forty-two patients operated-on since 1997 were categorized by hemorrhage status and hemosiderin positivity in this cohort study: unruptured (group 1), silent hemorrhage (group 2), and ruptured/reruptured (group 3/4). Group 3/4 was combined because hemosiderin cannot distinguish acute hemorrhage from older silent hemorrhage.

RESULTS

Hemosiderin was found in 45% of specimens. Seventy-five patients (31.0%) had unruptured AVMs, 30 (12.4%) had silent hemorrhage, and 137 (56.6%) had ruptured/reruptured AVMs. Deep drainage, posterior fossa location, preoperative modified Rankin Scale (mRS) score, outcome, and macrophage score were different across groups. Only the macrophage score was different between the groups without clinical hemorrhage. Outcomes were better in silent hemorrhage patients than in those with frank rupture (mean mRS scores of 1.2 and 1.7, respectively).

CONCLUSION

One-third of patients present with silent AVM hemorrhage. No clinical or anatomic features differentiate these patients from unruptured patients, except the presence of hemosiderin and macrophages. Silent hemorrhage can be diagnosed using magnetic resonance imaging with iron-sensitive imaging. Silent hemorrhage portends an aggressive natural history, and surgery halts progression to rerupture. Good final mRS outcomes and better outcomes than in those with frank rupture support surgery for silent hemorrhage patients, despite the findings of ARUBA.

Cerebral amyloid angiopathy-related inflammation presenting with steroid-responsive higher brain dysfunction: case report and review of the literature

A 56-year-old man noticed discomfort in his left lower limb, followed by convulsion and numbness in the same area. Magnetic resonance imaging (MRI) showed white matter lesions in the right parietal lobe accompanied by leptomeningeal or leptomeningeal and cortical post-contrast enhancement along the parietal sulci. The patient also exhibited higher brain dysfunction corresponding with the lesions on MRI. Histological pathology disclosed β-amyloid in the blood vessels and perivascular inflammation, which highlights the diagnosis of cerebral amyloid angiopathy (CAA)-related inflammation. Pulse steroid therapy was so effective that clinical and radiological findings immediately improved.CAA-related inflammation is a rare disease, defined by the deposition of amyloid proteins within the leptomeningeal and cortical arteries associated with vasculitis or perivasculitis. Here we report a patient with CAA-related inflammation who showed higher brain dysfunction that improved with steroid therapy. In cases with atypical radiological lesions like our case, cerebral biopsy with histological confirmation remains necessary for an accurate diagnosis.