Fig. 1

This figure shows hemispheres from a patient in the low EPVS group (a) and a patient in the high EPVS group (b). In the left hemisphere of the patient with a low EPVS grade (a 38-year-old female), the mean number of EPVS was 10.5, and the hemisphere was categorized as a grade 1 (a). In the left hemisphere of the patient with a high EPVS grade (a 36-year-old female), the mean number of EPVS was 83, and the hemisphere was categorized as a grade 4 (b). The white arrow shows dot-like EPVS, and the black arrow shows linear EPVS