Table 1 –
Studies entered into the meta-analysis are listed based on the method of analysis and year of publication.
| Author, year | Number of subjects (PD/controls) | Number of female subjects (PD/controls) | Age of PD/controls (Mean ± SD) | Imaging method | Medication status | Number of foci | Covariates | UPDRS-score | |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Chen et al. (2015) | 31 (12 TD, 19 PIGD)/22 | 15 (8 TD, 7 PIGD)/10 | 62.6 ± 8.71 (TD), 64.8 ± 8.34 (PIGD)/65.1 ± 5.00 | ALFF | ON | 12 | Age, gender, Levodopa equivalent daily dosage, grey matter volume | TD: Part III: 19.1 ± 11.5 PIGD: Part III: 21.6 ± 11.6 |
| 2 | Hu et al. (2015) | 17/20 | 7/9 | 60.29 ± 12.03/58.48 ± 6.89 | ALFF | ON | 3 | Mean FD | Baseline: Part III: 17.11 ± 6.12 Follow-up: Part III: 17.29 ± 6.30 |
| 3 | Wu et al. (2015) | 58/54 | 25/26 | 61.4 ± 9.0/61.1 ± 9.4/ | ALFF | OFF | 31 | N/S | Part III (OFF): 24.8 ± 8.2 |
| 4 | Yao et al. (2014) | 24 (12 PD_nonVH, 12 PD_VH)/14 | 17 (8 PD_nonVH, 9 PD_VH)/8 | 63.4 ± 7.4 (PD_nonVH), 67.6 ± 7.4 (PD_VH)/64.1 ± 4.0 | ALFF | ON | 12 | Depression scores | PD_nonVH: Part III: 18 ± 12.9 PD_VH: Part III: 20.9 ± 10.6 |
| 5 | Hou et al. (2014) | 109/106 | 42/42 | 59.84 ± 7.15/59.91 ± 7.09 | ALFF | OFF | 23 | N/S | Part III (OFF): 25.54 ± 11.51 |
| 6 | Luo et al. (2014) | 59 (29 PD_D, 30 PD_nonD)/30 | 30 (15 PD_D, 15 PD_nonD)/15 | 51.46 ± 8.21 (PD_D) 53.64 ± 10.18 (PD_nonD)/51.9 ± 7.70 | ALFF | Drug naive | 1 | Age, gender | PD_D (naïve): Part I: 3.69 ± 2.00 Part II: 9.93 ± 6.69 Part III: 28.34 ± 16.9 Part IV: 0 PD-nonD (naïve): Part I: 1.23 ± 1.33 Part II: 8.40 ± 4.44 Part III: 26.83 ± 12.44 Part IV: 0 |
| 7 | Skidmore et al. (2013) | 14/15 | 3/6 | 62 ± 9/65 ± 13 | ALFF | OFF | 8 | Head motion | OFF: Part I: 4 ± 3 Part II: 12 ± 8 Part III: 37 ± 13 Part VI: 3 ± 2 TOTAL: 56 ± 23 |
| 8 | Wen et al. (2013) | 33 (17 PD_D, 16 PD_nonD)/21 | 26 (10 PD_D, 8 PD_nonD)/8 | 64.4 ± 13.4 (PD_D), 60.7 ± 18.7 (PD_nonD)/55.4 ± 16.4 | ALFF | OFF | 36 | N/S | Probably Total Score: PD_D (OFF): 42 ± 46 PD_nonD (OFF): 33.8 ± 24.2 |
| 9 | Zhang et al. (2013) | 72/78 | 47/46 | 59.7 ± 11.9/58.6 ± 8.5 | ALFF | OFF | 18 | Age, gender, mean grey matter volumes, mean relative FD | Part III (OFF): 20.24 ± 8.44 |
| 10 | Kwak et al. (2012) | 24/24 | 2/5 | 64 ± 8/63 ± 7 | ALFF | ON versus OFF | 35 | N/S | Part III (ON): 17.3 ± 8 Part III (OFF): 18.5 ± 8 |
| 11 | Borroni et al. (2015) | 21 (11 PD, 10 PD_CI)/10 | 13 (1 PD, 4 PD_CI)/7 | 66.3 ± 3.8 (PD), 74.5 ± 4.6 (PD_CI),/62.2 ± 8.0 | ReHo | N/S | 4 | VBM | PD: Part III: 10.7 ± 5.4 PD_CI: Part III: 27.9 ± 10.5 |
| 12 | Zhang et al. (2015) | 47 (27 AR, 20 TD),/26 | 21 (11 AR, 10 TD)/15 | 63.38 ± 9.46 (AR), 54.55 ± 12.58 (TD)/59.31 ± 7.15 | ReHo | OFF | 58 | Gender, age, mean grey matter volumes, mean relative FD | AR: Part III (OFF): 19.88 ± 6.70 TD: Part III (OFF): 19.35 ± 9.35 |
| 13 | Sheng et al. (2014) | 41 (20 PD_D, 21 PD_nonD)/25 | 15 (8 PD_D, 7 PD_nD)/9 | 55.9 ± 7.4 (PD_D) 57.3 ± 6.1(PD_nonD)/56.7 ± 5.3 | ReHo | OFF | 12 | N/S | PD_D: Part III (OFF): 39.4 ± 10.8 PD_nonD: Part III (OFF): 43.8 ± 8.2 |
| 14 | Choe et al. (2013) | 22/25 | 12/15 | 58.3 ± 2.4/58.3 ± 1.7 | ReHo | OFF | 11 | N/S | Part III (OFF): 10.4 ± 1.2 |
| 15 | Yang et al. (2013) | 17/17 | 7/7 | 60.43 ± 9.65/60.73 ± 8.57 | ReHo | OFF | 17 | N/S | Part III (OFF): 20.57 ± 3.82 |
| 16 | Wu et al. (2009) | 22/22 | 6/N/S | 59.5 ± 8.1/59.7 ± N/S | ReHo | ON versus OFF | 39 | N/S | OFF: 25.6 ± 8.1 |
| 17 | Tinaz et al. (2015) | 30/30 | 11/10 | 61.2 ± 8.4/61.4 ± 6.7 | Graph | OFF | 21 | N/S | Part III (OFF): 28.4 ± 11.7 TOTAL (OFF): 46.5 ± 15.2 |
| 18 | Wei et al. (2014) | 37/34 | 20/12 | 58.68 ± 13.10/55.59 ± 10.55 | Graph | OFF | 12 | age, gender and mean FD | Part III (OFF): 19.17 ± 9.22 |
| 19 | Gottlich et al. (2013) | 37/20 | 15/10 | 65 ± 10/63 ± 9 | Graph | ON | 10 | N/S | Part III (ON): 22.3 ± 7.7 |
| 20 | Baggio et al. (2014) | 65 (22 PD_CI, 43 PD_nonCI)/36 | 42 (8 PD_CI, 20 PD_nonCI)/17 | 66.1 ± 12.2 (PD_CI), 64.0 ± 9.8 (PD_nonCI)/63.4 ± 10.5 | Network | ON | 5 | Head motion | PD_CI: Part III (ON): 18.2 ± 8.7 PD_nonCI: Part III (ON): 14.1 ± 7.5 |
| 21 | Gorges et al. (2015),a | 31 (17 PD_CI, 14 PD_ nonCI)/22 | 12 (9 PD_CI, 3 PD_ nonCI)/7 | 69 ± 8 years PD-CI), 67 ± 10 (PD_ nonCI)/68 ± 6 years | Network | ON | 68 | N/S | PD_all: Part III (ON): 12 (8–14) PD_CI: Part III (ON): 12 (9–18) PD_nonCI: Part III (ON): 10 (5–13) |
| 22 | Madhyastha et al. (2015) | 24/21 | 7/12 | 66.08 ± 10.27/61.90 ± 10 | Network | ON | 4 | N/S | Part I: 9.78 ± 5.81 Part II: 8.38 ± 5.08 Part III: 23.12 ± 8.61 Part IV: 1.88 ± 3.72 |
| 23 | Onu et al. (2015) | 27/16 | N/S | 68.7 ± 10.6/67 ± 11.5 | Network | OFF | 35 | N/S | Part III (OFF): 28.4 ± 9.5 Part III (ON): 9.2 ± 5.2 |
| 24 | Tan et al. (2015) | 14/17 | 3/4 | 62.79 ± 4.59/61.35 ± 4.27 | Network | Drug naive | 6 | N/S | Naïve: Part I: 2.93 ± 1.14 Part II: 9.93 ± 2.27 Part III: 21.79 ± 5.66 Part VI: 0 |
| 25 | Szewczyk-Krolikowski et al. (2014) | 19/19 | 9/8 | 58.9 ± 10.8/60.6 ± 7.7 | Network | ON versus OFF | 14 | N/S | Discovery: Part III: 23.9 ± 9.6 Validation: Part III: 29.7 ± 14.7 |
| 26 | Amboni et al. (2014) | 42 (21 PD_CI, 21 PD_nonCI)/20 | 10 (3 PD_CI, 7 PD_nonCI)/8 | 65.2 ± 8.7 (PD_CI), 65.8 ± 6.5 (PD_nonCI)/61.9 ± 9.2 | Network | ON | 8 | Total intracranial volume, age and gender | PD_CI: Part III (ON): 14.3 ± 8.5 PD_nonCI: Part III (ON): 13.1 ± 5.3 |
| 27 | Esposito et al. (2013) | 20 (10 levodopa, 10 placebo)/18 | 10 (5 levodopa, 5 placebo)/8 | 60.8 ± 8.66 (levodopa), 66.7 ± 5.29 (placebo)/59.2 ± 1.52 | Network | ON versus OFF | 3 | N/S | Levodopa: Part III (OFF): 16.3 ± 3.91 Part III (ON): 10.7 ± 3.19 Placebo: Part III (OFF): 20.5 ± 7.09 Part III (ON): 19.8 ± 7.88 |
| 28 | Tessitore et al. (2012) | 16/16 | 4/4 | 64.15 ± 1.64/65.5 ± 6.17 | Network | ON | 2 | Total intracranial volume and age | Part III (ON): 11.50 ± .97 |
ALFF = amplitude of low frequency fluctuation; FD = frame-wise displacement; PD = Parkinson’s disease; PD_CI = Parkinson patients with cognitive impairment; PD_nonCI = Parkinson patients without cognitive impairment; PD_D = Parkinson patients with depression; PD_nonD = Parkinson patients without depression; PD_VH = Parkinson patients with visual hallucinations; PD_nonVH = Parkinson patients without hallucinations; PIGD = postural instability/gait difficulty; ReHo = regional homogeneity; TD = tremor-dominant; UPDRS = Unified Parkinson’s Disease Rating Scale (Part I = non-motor aspects of experiences of daily living, Part II = motor aspects of experiences of daily living, Part III = motor examination, Part IV = motor complications); VBM = voxel-based morphometry.
a
Data are given as median (interquartile range).