According to the modified Boston criteria, cerebral amyloid angiopathy (CAA) can present with lobar hematoma (LH) or superficial siderosis (SS). Recently, decreased CSF β-amyloid peptide 40 and 42 (Aβ40; Aβ42) and increased total and phosphorylated tau (t-tau; p-tau) concentrations have been described in CAA presenting with LH. Our aim was to analyze CSF biomarkers as a diagnostic tool for CAA according to the modified Boston criteria. We prospectively included patients with possible or probable CAA according to the modified Boston criteria. CSF was analyzed for t-tau, p-tau, Aβ42, and Aβ40. Data were compared with AD patients (n = 42) and controls (n = 14). Thirteen CAA patients were included, nine presenting with LH and four with SS. T-tau and p-tau levels in CAA were higher than controls, but lower than in AD. Differences in t-tau and p-tau levels between CAA versus controls and AD were all significant apart of the CAA p-tau levels comparison with controls. Aβ42 levels in CAA were significantly lower than in controls, and slightly higher than in AD, though non-significantly. Aβ40 levels in CAA were non-significantly lower than in controls, and significantly lower than in AD. Combining the findings of our study and the earlier report, we confirm that patients with suspected CAA have significantly different values for t-tau, Aβ42, Aβ42/t-tau, and Aβ40. Especially Aβ40 levels seem to be of clinical interest to differentiate CAA from AD. CSF biomarkers have to be analyzed in a larger number of CAA patients, and compared to patients with other disorders causing LH or SS.

No abstract

Objective: To describe the clinico-radiological features and long-term prognosis in patients with cerebral amyloid angiopathy-related inflammation (CAA-ri). Methods: Twenty-eight CAA-ri patients were recruited retrospectively from 6 neurological centers. We recorded the clinico-radiological and biological data, at baseline and during follow-up. Baseline characteristics associated with relapse risk and prognosis were assessed. Results: Five patients had pathologically confirmed CAA-ri whereas 23 had probable (n = 21) or possible (n = 2) CAA-ri. The mean age was 72 years; main clinical symptoms included confusion (54%), hemiparesis (36%), and aphasia (29%). Cerebral MRI disclosed a brain parenchymal lesion (89%), which was usually multifocal (82%) and bilateral (89%). It was associated with gadolinium enhancement (84%), small ischemic lesions (39%), cortical superficial siderosis (CSS; 50%), and a high number of microbleeds (mean 240 ± 277). An isolated leptomeningeal involvement was observed in 3 patients with pathological confirmation. Despite a favorable initial evolution after treatment, we observed a 42% risk of relapse, mostly within the first year (83%). After a mean follow-up of 2 years, 29% died and 25% had a marked disability. Disseminated CSS was associated with death. Conclusion: Despite an apparently favorable initial evolution, CAA-ri is characterized by a poor prognosis. Diagnostic criteria should consider patients with isolated leptomeningeal involvement.

Compared to CAA, CAA-ri was associated with higher CMB numbers, more frequent ApoE4 carriers and homozygotes, lower CSF Aβ42 levels, and more severe amyloid load on FBB-PET.

CSF biomarkers profile similar to that of CAA was observed in CAA-I (with even lower levels of Aβ42 compared to CAA). Based on our findings, high p-tau seems more specific for AD, whereas low Aβ42 differentiates CAA-I from CAA, PACNS, and controls, and low Aβ40 differentiates CAA-I from AD.