Table 1 Common magnetic resonance imaging findings in Parkinson’s disease and atypical parkinsonian syndromes
From: Imaging biomarkers in Parkinson’s disease and Parkinsonian syndromes: current and emerging concepts
Neuropathology | Disorders | MRI signs | Structural/volumetric MRI findings | Diffusion Tensor MRI findings | Proton MRS findings |
|---|---|---|---|---|---|
Synucleinopathies | PD | 1. Swallow tail sign 2. Loss of nigrosome-1 | ↓ in frontal lobe, hippocampus, anterior cingulate and superior temporal gyri, and olfactory bulb and tract volumes vs. HC [12, 13, 17] ↓ in orbitofrontal, ventrolateral, prefrontal and occipitoparietal cortex vs. HC [15] ○ or ↓ in caudate, putamen and brainstem volumes vs. HC [14–16] | DTI may be normal in early-PD vs. HC [73]. ↓ FA in SN and anterior olfactory structures; and ↑ D̄ in olfactory bulb and tracts vs. HC [69–72]. ↑ in D̄ primarily in corpus callosum, putamen, midbrain, cerebellum and cerebellar peduncles may distinguish atypical PS from PD [74]. | ↓ in NAA and NAA/Cr levels in LN, temporoparietal and posterior cingulate cortex, and in pre-SMA vs. HC [88–91] |
PDD/DLB (LBD) | ↓ in temporal, occipital, frontal and parietal cortices in PDD vs. HC [12, 27]. ↓ in temporal, occipital and parietal cortices may be seen in DLB vs. PDD [33] ↓ in occipital and entorhinal cortices in PDD vs. PD [12, 35]. ↓ in thalamic, amygdala and nucleus accumbens volumes, and ↑ in rate of temporal, occipital, parietal and SMA cortical thinning in PD-MCI vs. PD-non-MCI [39, 40] | ↑ WM abnormalities in corpus callosum, dorsal striatum, frontal, parietal and occipital regions, as well as in amygdala and inferior longitudinal fasciculus in DLB with less temporal involvement vs. HC [84, 85]. ↓ FA in parietal lobe (precuneus) in DLB vs. AD [86]. | ↓ in NAA/Cr values in the posterior cingulate gyrus and medial temporal lobe structures in DLB and PDD, although to a lesser degree than in AD [98, 99]. | ||
MSA | 1. Putaminal rim sign 2. Hot-cross-bun sign 3. MCP sign | ↓ in putamen, MCP, cerebellum, pons and striatal volumes in MSA-P and MSA-C vs. HC [6, 16]. ↓ in putaminal, cerebellar and pontine volumes in MSA vs. PD [16, 44, 45] ↓ in primary and SMA, prefrontal and insular cortices, striatum and midbrain in MSA-P vs. PD and HC [49] ↑ cortical thinning in parahippocampal and lingual cortex in MSA-demented vs. MSA-non-demented [50] | ↑ putaminal D̄ in MSA-P vs. PD, MSA-C and HC [74, 75]. ↓ FA and ↑ ADC in MSA-P in putamen, cerebellum and pons vs. PD and HC [76]. ↓ FA in MCP, inferior cerebellar peduncle, and ventral pons in MSA-C vs. HC [79]. ↓ FA and ↑D̄ in MCP and pons vs. HC [77, 80]. ↑ ADC in cerebellum and MCP in MSA-C vs. MSA-P and HC [80]; ↓ FA in MCP vs. PSP and HC [77, 78] | ↓ in NAA/Cr ratio in putamen and pontine base in MSA vs. PD and HC [96]. | |
Tauopathies | PSP | 1. Hummingbird sign 2. Morning glory sign | ↓ in prefrontal, frontal, insular, premotor, SMA, hippocampus and parahippocampal regions; ↓ WM in pulvinar, thalamus, colliculus, mesencephalon and frontotemporal regions; ↓ in midbrain, pons, thalamus and striatum, vs. HC [57, 58]. ↓ in midbrain and SCP volumes vs. PD, MSA-P, CBS and HC [54, 55, 59, 61, 62] ↓ in brainstem, midbrain and frontal cortex vs. HC [56] ↓ midbrain atrophy and ↑ cortical/subcortical atrophy in PSP with dementia [61] | ↑ D̄ or ADC in decussation of SCP, thalamus, cingulum, motor and SMA; ↓ FA in the frontal inferior frontooccipital fasciculus, superior longitudinal fasciculus, arcuate fasciculus, posterior thalamic radiations, internal capsule, orbitofrontal WM, anterior cingulum, motor area vs. HC [58, 78, 81, 82] ↑ ADC in putamen and pons in MSA-P vs. MSA-C and HC [80] ↑ D̄ in midbrain and SCP vs. atypical PS group [74]. ↑ ADC in putamen, globus pallidus and caudate nucleus vs. PD [83]. | ↓ in NAA/Cr ratio in LN, brainstem, centrum semiovale, frontal and precentral cortex vs. HC [93, 94]. Relatively greater ↓ in NAA/Cr ratio in putamen and frontal cortex vs. PD [86, 88, 95]. |
CBD/CBS | ↑ global brain atrophy in CBD vs. PSP [66] ↓ in bilateral frontal cortex (including SMA), dorsolateral prefrontal cortex, pre/post-central gyri, striatum, and brainstem in CBD vs. HC [68] ↓ in frontal and insula cortex with scarce WM atrophy in CBD-dementia; moderate ↓ in GM/WM of these regions in CBD with early extrapyramidal manifestations [61] ↓ in prefrontal cortex and parietal lobe, respectively, in CBD-FTD and CBD-AD [11] | ↓ FA in the long frontoparietal connecting tracts, intraparietal associative fibers, corpus callosum and sensorimotor projections of cortical hand areas, in CBS vs. HC [65]. ↓ FA and ↑ D in posterior truncus of corpus callosum may differentiate CBS from PD [73]. | ↓ in NAA and NAA/Cr levels contralaterally in frontoparietal cortex, LN, centrum semiovale and putamen, in CBS vs. HC [94, 95, 97]. Greater ↓ in NAA and NAA/Cr levels in frontal cortex and putamen with marked putaminal asymmetry, in CBS vs. PD, MSA and vascular parkinsonism [95] |