SMPD1 and Lewy body dementia: Neuro2a cells displayed a high number of bilayered vesicles, potentially autophagosomes, where sphingomyelin is converted to ceramide by acidic sphingomyelinase.65 The increased presence of these vesicles could thus explain the upregulation of ceramide found during the aggregation process.66 Elevated ceramide levels have also been reported in the plasma of DLB patients.22,67,68 In multiple systems atrophy, which is characterized by α-synuclein deposits in oligodendrocytes, decreased sphingomyelin levels negatively correlated with α-synuclein expression.69