Amyloid accumulation in cases of suspected comorbid cerebral amyloid angiopathy and isolated cortical venous thrombosis

Background and aim: The differentiation of isolated cortical venous thrombosis (ICVT) from cerebral amyloid angiopathy (CAA) can be difficult because both diseases share similar neurological symptoms and imaging findings. N-methyl-11C-2-(4 '-methylaminophenyl)-6-hydroxybenzo-thiazole (11C-PiB) positron emission tomography (PET) functions as a diagnostic modality for CAA by detecting amyloid deposition. The present prospective study evaluated amyloid deposition using 11C-PiB-PET in consecutive patients with suspected ICVT. Method: This study was a prospective observational study. Patients who attended or were hospitalized between May 2019 and March 2020 were included in the analysis. Consecutive patients who met the criteria for suspicion of ICVT were enrolled in the study, and the clinical course, symptoms, imaging findings (including magnetic resonance imaging), and the 11C-PiB-PET findings of each case were analyzed. Results: The study cohort included four patients (64-82 years of age, all women). In one younger patient, 11C-PiB- PET afforded no findings suggestive of CAA, whereas the remaining three patients exhibited 11C-PiB-PET findings suggestive of CAA. Conclusion: Although 11C-PiB-PET would be a reasonable modality for distinguishing ICVT from CAA, especially in younger patients, it might be difficult to differentiate ICVT from CAA in elderly patients because of the potential deposition of amyloid. Clinical trial registration: URL: https://www.umin.ac.jp/ctr/ Unique identifier: UMIN 000037101.