Abstract: A range of neurodegenerative disorders, collectively termed parkinsonian disorders, present with a complex array of both motor and non-motor symptoms. Included in this group are Parkinson’s disease (PD), dementia with Lewy bodies (DLB), multiple system atrophy (MSA), corticobasal syndrome (CBS), and progressive supranuclear palsy (PSP). These disorders are differentiated neuropathologically by their dominant protein pathologies involving α-synuclein (α-syn) and/or tau, the types of brain cells affected, such as neurons, oligodendroglia, and astrocytes, and the specific brain regions involved (Tolosa et al., 2021). However, because definite diagnosis can only be achieved postmortem, parkinsonian disorders commonly pose diagnostic challenges for experts in movement disorders due to parkinsonism symptom overlap (Figure 1) including bradykinesia, rigidity, and tremor. This is especially problematic in the early stages of the conditions where more distinguishable symptoms may not be yet present (Rizzo et al., 2016).