Table 1.
MRI characteristics in vascular parkinsonism and neurodegenerative parkinsonism
| MRI | VaP | IPD | PSP | MSA |
|---|---|---|---|---|
| Conventional MRI |
Periventricular white matter lesion, lacunar infarcts in the basal ganglion, dilatation of lateral and third ventricles [19,47] Presence of microbleed, subcortical or cortical atrophy [41,47] |
Hummingbird sign Morning glory sign |
Hot cross bun sign | |
| MRI volumetrics |
↑ WMH volume in VaP vs IPD with cutoff of > 0.6% of brain tissue volume [47] ↑ WMH volume and caudate volume in VaP vs IPD and HC [43•] ↓ midbrain area, pons area, midbrain to pons in VaP vs IPD and PSP [25, 44•, 45•] ↓ SNpc width in IPD vs VaP [103] |
↓ caudate and putamen volume in IPD vs HC |
↓ midbrain area, midbrain to pons ratio, pons area in PSP vs VaP [44•, 45•] ↑ MRPI in PSP vs VaP, MSA, IPD and HC [44•, 45•, 64, 67, 68] ↓ midbrain and SCP volume in PSP vs IPD, MSA and HC [61, 62, 83] ↓ midbrain to pons ratio in PSP vs IPD and MSA [65] |
↓ putamen, cerebellum and pons volume in MSA vs IPD and HC [58–60] |
| Diffusion tensor imaging (DTI) | ↓ FA and ↑ MD in frontal lobe, internal capsule, corpus callosum in VaP vs IPD and HC [48, 77, 78•] | ↓ FA in substantia nigra in IPD vs HC [74] | ↓ FA and ↑ MD in frontal area, midbrain, basal ganglion, SCP in PSP vs IPD [74, 76] | ↓ FA and ↑ MD in pons, putamen, MCP in MSA vs IPD [74, 75] |
| Neuromelanin sensitive MRI | ↓ contrast to noise ratio and neuromelanin positive SN volume in IPD vs HC [86, 87] | ↓ neuromelanin positive SN volume in PSP vs HC [86] | ↓ contrast to noise ratio and neuromelanin positive SN volume in MSA vs HC [86, 87] | |
| Susceptibility weighted imaging (SWI) | Intact dorsal nigral hyperdensity in VaP vs IPD, MSA, PSP [83] | Loss of dorsal nigral hyperdensity in IPD vs HC [84•] | Loss of dorsal nigral hyperdensity in PSP vs HC [84•] | Loss of dorsal nigral hyperdensity in MSA vs HC [84•] |
↓, decrease; ↑, increase; VaP, vascular parkinsonism; IPD, idiopathic Parkinson’s disease; PSP, progressive supranuclear palsy; HC, healthy control; MSA, multiple system atrophy; WMHL, white matter hyperdense lesion; MRPI, magnetic resonance parkinsonism index; M/P, midbrain to pons ratio; SCP, superior cerebellar peduncle; MCP, middle cerebellar peduncle; SNpc, substantia nigra pars compacta; SN, substantia nigra; FA, fractional anisotropy; MD, mean diffusivity