The death of dopamine neurons in a small nucleus deep down in the brainstem, the substantia nigra, leads to the core movement symptoms in Parkinson’s disease. But can we see these changes in the living brain? With ultra-high field 7T MRI, yes—we can. Here's how:

In his study, Christopher (headed by David Meder and Hartwig Siebner) used two types of imaging to look closely at the substantia nigra:

• Neuromelanin-sensitive MRI to detect dopamine neuron loss
• SWI + QSM to track iron buildup

Both are key features of Parkinson’s disease.

We found that neuron loss and iron accumulation spatially overlap in some sub-regions of the substantia nigra but also show differences in other parts. As shown before, these disease processes prominently occur in the nigrosome 1, the largest high density dopamine cell cluster. But here’s what’s new: we also found signs of disease in nigrosomes 2 and 4. These may be new “hotspots” of Parkinson’s pathology that haven’t been studied as much before.

Which scans were most helpful?

• Neuromelanin-sensitive MRI and QSM clearly showed differences between healthy people and those with Parkinson’s disease.

• SWI best linked iron levels with how severe residual (remaining despite dopamine treatment) motor symptoms were.

Our research shows that 7T MRI can uncover fine-grained details of Parkinson’s in the brain—helping us better understand how and where the disease strikes.

Read the full (open access) paper HERE.