von Economo neurones are selectively targeted in frontotemporal dementia

BACKGROUND: von Economo neurones (VEN) are bipolar neurones located in the anterior cingulate cortex (ACC) and the frontoinsular cortex (FI), areas affected early in behavioural variant frontotemporal dementia (bvFTD), in which VEN may constitute a selectively vulnerable cellular population. AIM: A previous study has shown a selective loss of VEN in FTD above other neurones in the ACC of FTD. The aim of this study was to confirm this finding in a larger cohort, using a different methodology, and to examine VEN loss in relation to neuropathological severity and molecular pathology. METHODS: VEN and neighbouring neurones (NN) were quantified in layers Va and Vb of the right dorsal ACC in 21 cases of bvFTD, 10 cases of Alzheimer's disease (AD) and 10 non-demented controls (NDC). RESULTS: A marked VEN reduction was seen in all FTD cases. In the neuropathologically early cases of FTD (n = 13), VEN/10 000 NN was significantly reduced by 53% compared with NDC (P < 0.001) and 41% compared with AD (P = 0.019), whereas AD patients showed a non-significant 30% reduction of VEN/10 000 NN compared with NDC. VEN reduction was present in all protein pathology subgroups. DISCUSSION: In conclusion, this study confirms selective sensitivity of VEN in FTD and suggests that VEN loss is an early event in the neurodegenerative process.