These findings, not yet further confirmed by following studies, showed that EDS was associated with a reduction in CSF orexin-A levels, whereas impulsivity and extrapyramidal signs were associated with an increase in CSF orexin-A concentrations, which could explain the very high spread of CSF orexin-A levels documented in the patients with bv-FTD and NFPA included in this study (see Fig. 1). Here, HCRT is linked to frontotemporal dementia.