Magnetic Resonance Imaging and Neurofilament Light in the Differentiation of Parkinsonism

Congratulations to Drs. Nikolaus McFarland, Michael Okun and David Vaillancourt on the publication of “Magnetic Resonance Imaging and Neurofilament Light in the Differentiation of Parkinsonism.”  This research article was published in the May 1, 2020 edition of Movement Disorders.



Accurate diagnosis is particularly challenging in Parkinson’s disease (PD), multiple system atrophy (MSAp), and progressive supranuclear palsy (PSP). We compare the utility of 3 promising biomarkers to differentiate disease state and explain disease severity in parkinsonism: the Automated Imaging Differentiation in Parkinsonism (AID‐P), the Magnetic Resonance Parkinsonism Index (MRPI), and plasma‐based neurofilament light chain protein (NfL).


For each biomarker, the area under the curve (AUC) of receiver operating characteristic curves were quantified for PD versus MSAp/PSP and MSAp versus PSP and statistically compared. Unique combinations of variables were also assessed. Furthermore, each measures association with disease severity was determined using stepwise multiple regression.


For PD versus MSAp/PSP, AID‐P (AUC, 0.900) measures had higher AUC compared with NfL (AUC, 0.747) and MRPI (AUC, 0.669), P < 0.05. For MSAp versus PSP, AID‐P (AUC, 0.889), and MRPI (AUC, 0.824) measures were greater than NfL (AUC, 0.537), P < 0.05. We then combined measures to determine if any unique combination provided enhanced accuracy and found that no combination performed better than the AID‐P alone in differentiating parkinsonisms. Furthermore, we found that the AID‐P demonstrated the highest association with the MDS‐UPDRS (Radj2–AID‐P, 26.58%; NfL,15.12%; MRPI, 12.90%).


Compared with MRPI and NfL, AID‐P provides the best overall differentiation of PD versus MSAp/PSP. Both AID‐P and MRPI are effective in differentiating MSAp versus PSP. Furthermore, combining biomarkers did not improve classification of disease state compared with using AID‐P alone. The findings demonstrate in the current sample that the AID‐P and MRPI are robust biomarkers for PD, MSAp, and PSP. © 2020 International Parkinson and Movement Disorder Society