October 30, 2026

@michaelokun

Neuromelanin-sensitive MRI has made great strides. What resonates most with me about this important 2026 Movement Disorders systematic review and meta-analysis by Akande and colleagues is the possibility that we are moving closer to actually visualizing and measuring the biological progression of Parkinson’s disease, rather than relying primarily on clinical symptoms. Across 39 studies involving 1,983 people with Parkinson’s, neuromelanin-sensitive MRI demonstrated meaningful associations between loss of signal in the substantia nigra and worsening motor symptoms, longer disease duration, and more advanced disease stages. Particularly compelling was the distinction between the substantia nigra, which correlated predominantly with motor disability, and the locus coeruleus, which was more closely associated with cognition, mood, sleep, and autonomic dysfunction. This reminds us that Parkinson’s is much more than a dopamine deficiency or a movement disorder. Four longitudinal studies also suggested that neuromelanin MRI measures may decline over time, raising the exciting possibility of tracking neurodegeneration and evaluating future disease-modifying therapies. We must remain cautious: imaging protocols require standardization, and these measures are not yet validated progression biomarkers. The real opportunity is to move beyond measuring how a person with Parkinson’s performs on an examination toward measuring what is actually happening inside the brain. That could fundamentally change how we design clinical trials and ultimately deliver personalized Parkinson’s care. https://movementdisorders.onlinelibrary.wiley.com/doi/10.1002/mds.70588