[New Diagnostic Criteria for Parkinson's Disease: MDS-PD Criteria]

The International Parkinson and Movement Disorder Society offered standard diagnostic criteria for Parkinson's disease (PD) in 2015. These diagnostic criteria provided systematization of the diagnostic process and detailed explanations of parkinsonism, absolute exclusion criteria, red flags, and supportive criteria. The presence of parkinsonism was a core feature of the criteria. Clear instructions for defining the motor features were described. With regard to the novel aspects, non-motor manifestations (hyposmia, autonomic dysfunction, psychiatric dysfunction, and sleep dysfunction) and ancillary diagnostic tests (olfactory test, cardiac MIBG scintigraphy, and presynaptic dopaminergic imaging) were incorporated. Absolute exclusion criteria comprised 9 features that have the potential to exclude PD with greater than 97% sensitivity. The presence of dementia during the early stage of the illness was not classified as an exclusion criterion. The 10 red flags that indicate another cause of parkinsonism but can also be observed in pathologically proven PD were listed. Red flags were counterbalanced by supportive criteria to allow diagnosis of PD. These 4 supportive criteria were highly specific for a diagnosis of PD. With regard to the level of certainty, clinically established PD and clinically probable PD were described. In this review, we summarize the main points of the MDS-PD criteria and discuss the utility and limitations.