TABLE 3.
Summary of MRI studies cited in the text relevant to cholinergic dysfunction and cognitive impairment
| Author, year | Imaging technique | No. and types of patients | Findings |
|---|---|---|---|
| Oikawa et al, 200452 | 1.5 T MRI (T2 FSE) | 44 PD (4 pts with MMSE <23), 20 HCs |
SI thickness in PD significantly reduced compared to HCs, especially in pts with dementia. Significant positive correlation between SI thickness and MMSE. |
| Choi et al, 201253 | 3 T MRI (3D T1 TFE) | 24 PD, 35 PD‐MCI, 29 PDD, 28 HCs |
SI volume significantly decreased in all pts compared to controls, and lower in PDD compared to PD and PD‐MCI. SI volume significantly associated with cognitive status and performance in cognitive subdomains, especially attention and object naming. |
| Ray et al, 201854 | 3 T MRI (3D T1 MP‐RAGE) |
168 de novo PD, 76 HCs MRI baseline analysis, 5‐yr longitudinal clinical analysis |
Ch4p volume reduced in PD pts with MCI. Reduced Ch4 volume independently increases the risk of MCI or PDD in the subsequent 5 yr. No significant differences in cognitive performances at baseline between patients with normal and reduced Ch4 volume; pts with reduced Ch4 volume had faster decline in cognitive performances. |
| Gargouri et al, 201959 | 3 T MRI (3D T1, 3D T2, diffusion, resting state fMRI) | 52 non‐demented PD (20 MCI), 25 HCs |
Abnormal structural indices (mean, axial and radial diffusivity) in Ch1‐2‐3‐4. Reduced structural connectivity between Ch3‐4 and associative prefrontal, occipital, peri‐insular cortices. Reduced functional connectivity between Ch1‐2 and hippocampi and between Ch3‐4 and frontal areas and thalamus. Associations between structural and functional connectivity indices and specific cognitive performances. |
| Barrett et al, 201955 | 3 T MRI (3D T1 MP‐RAGE) | 228 de novo PD, 125 advanced PD, 101 HCs |
De novo PD had higher Ch123‐4 gray matter density compared to advanced PD. Ch123‐4 gray matter density associated with cognitive performances. In advanced PD, Ch123‐4 nuclei gray matter density was associated with MoCA and cognitive subdomains performances. Ch4 density associated with attention and visuospatial function in both groups. |
| Gang et al, 202056 |
1.5 T MRI (3D structural) [18F]FDG‐PET |
56 PD, 13 HCs Baseline and 3‐yr assessments |
At baseline 20 PD pts with nBM atrophy. Pts with nBM atrophy showed more severe cognitive, anxiety and apathy symptoms both at baseline and 3‐yr follow up. They also showed significantly reduced FDG uptake in parietal and occipital cortices at baseline and follow up. |
Abbreviations: AD, Alzheimer's disease; Ch123‐4, cholinergic groups 1–2, 3, and 4 of the basal forebrain; Ch4p, posterior part of the Ch4 cholinergic group of the basal forebrain; DLB, dementia with Lewy bodies; FDG, fluorodeoxyglucose; fMRI, functional MRI; FSE, fast spin; echo; HCs, healthy controls; MMSE, Mini Mental State Examination; MP‐RAGE, magnetization‐prepared rapid acquisition gradient echo; MRI, magnetic resonance imaging; nBM, nucleus basalis of Meynert; PD, Parkinson's disease; PDD, Parkinson's disease dementia; pts, patients; SI, substantia innominata; T, Tesla; TFE, turbo field echo.