NEFL and Brain atrophy: These findings go along with other research describing prodromal phases of HD, before the onset of distinct motoric symptoms (defined as diagnostic confidence level 4) and also go along with earlier observed neurocognitive, neuropsychiatric, biomarker, and structural MRI changes with brain atrophy in premanifest HD patients [40,41,42,43,44,45] Recently, CSF neurofilament light protein (NfL) was identified as a potential biomarker and is elevated far before the onset in pre-HD as a sensitive measure for neurodegenerative processes, starting decades before clinical onset [46].