We, therefore, purified EV from post-mortem CSF to high purity from 5 LBD (3 DLB, 1 PDD, 1 PD) cases with GBA mutations, 6 LBD cases (2 DLB, 2 PDD, 2 PD) without GBA mutations, and 4 controls without mutations in GBA (cases matching the brain tissue analysis). This evidence concerns the gene GBA1 and Parkinson disease.