Table 2 Table summarizing changes in the midbrain of pPD cases

iRBD

 Mild motor deficits

[165]

 ↓ Striatal dopamine transporter (DAT) and VMAT2 binding

[169, 170]

 Changes in brain glucose metabolism

[172]

 ↓ Nigrostriatal connectivity

[173,174,175,176,177,178,179,180,181,182,183]

 ↑ Microglial activation

[120]

 ↑ Activated astrocytes

[185]

 ↑ Serum neurofilament light chain (sNfL)

[190]

Hyposmia

 ↑ Echogenicity of the SNc

[191]

 ↓ DAT binding

[191]

 Correlation between olfactory performance and DAT binding

[192, 193]