Table 1.
Study demographics of all included studies.
| References | PD (n) | HC (n) | f/m PD | f/m HC | PD age (±SD) | HC age (±SD) | UPDRS III | Hoehn & Yahr | Disease duration (years) | Nil-finding | Task |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Vriend et al. (43) | 21 | 37 | 4/10 | 8/6 | 59.0 (±10.4) | 56.2 (±9.9) | 21.6 (±8.3) | 1.9 (±0.4) | 0.19 (±0.31) | No | Cognitive control task |
| Filip et al. (44) | 21 | 28 | 10/11 | 14/14 | 68 (±4.85) | 66.4 (±6.9) | Not stated | 2.24 (±0.57) | 7.69 (±3.8) | No | Cognitive: impulse control |
| Heller et al. (45) | 26 | 25 | 1/11 | 5/7 | 63.9 (±8.4) | 62.6 (±9.0) | 26.8 (±11.6) | 2 | 8.18 (±6.83) | No | Emotional processing |
| Yu et al. (31) | 8 | 8 | 6/14 | 10/10 | 59.4 (±8.4) | 59.5 (±9.5) | 31.1 (±10.8) | Not stated | 5.9 (±2.6) | No | Motor and auditory task |
| Martin et al. (46) | 22 | 22 | 4/10 | 5/9 | 52.5 (±10.7) | 48.5 (±12.4) | 15.6 (±6.4) | 1.4 (±0.6) | Not stated | No | Motor and planning task |
| Burciu et al. (47) | 20 | 20 | 1/8 | 5/10 | 65.8 (±8.0) | 64.8 (±8.8) | 31.9 (±9.6) | 2.0 (±0.3) | 4.14 (±1.65) | No | Motor and visual |
| Rottschy et al. (48) | 23 | 23 | 8/14 | 8/14 | 67.2 (±6.2) | 65 (±4.4) | 23.9 (±16.1) | 1.5 (±0.9) (ON) | 4.7 (±4.2) | No | Motor and working memory task |
| Pinto et al. (49) | 9 | 15 | 7/13 | 5/5 | 59 (±9) | 55 (±11) | 33 (±13) | Not stated | 14 (±7) | No | Motor hand movement and speech |
| Caproni et al. (50) | 11 | 11 | 3/8 | 3/8 | 65 (±4.98) | 65.1 (±5.86) | 20 (±4.5) | 2 | 3.8 (±1.5) | No | Motor task |
| Husárová et al. (51) | 20 | 21 | 9/11 | 10/11 | 55.4 (±9) | 57 (±7.3) | 18.08 (±3.8) | Not stated | 2.5 | No | Motor task |
| Poisson et al. (52) | 6 | 10 | 2/4 | 6/4 | 65 (±10) | 53.6 (±8.5) | 16 (±5.1) | Not stated | 5.4 (±4.6) | No | Motor task |
| Wu and Hallet (33) | 12 | 14 | 4/8 | 4/8 | 61.2 (±7.64) | 61.8 (±no SD) | 25.5 (±7.4) | 2.04 (±0.62) | 6.33 (±2.84) | No | Motor task |
| Jia et al. (53) | 22 | 22 | 8/14 | 8/14 | 61.04 (±4.38) | 60.59 (±4.64) | 16.45 (±4.63) | 1.64 (±0.44) | 4.04 (±1.81) | No | Motor task |
| Toxopeus et al. (54) | 12 | 18 | 5/7 | 9/9 | 59 (±9) | 58.7 (±5.4) | 22 (±7) | 2.0 (±0.5) | 6 (±4) | No | Motor task |
| Planetta et al. (55) | 14 | 14 | 7/12 | 17/5 | 64 (±8.7) | 61.9 (±8.4) | 29.6 (±5.3) | Not stated | 5.9 (±5.5) | No | Motor task |
| Neely et al. (56) | 14 | 14 | 5/5 | 6/5 | 64.0 (±8.7) | 60.2 (±9.2) | 29.6 (±5.3) | Not stated | Not stated | No | Motor task |
| Cerasa et al. (57) | 10 | 11 | 8/12 | 10/10 | 64.2 (±13.6) | 63.4 (±9.3) | 27.5 (±8.8) | 2.5 (±0.6) | 7.2 (±3.5) | No | Motor task |
| Schwingenschuh et al. (58) | 20 | 10 | 5/7 | 9/9 | 66.8 (±7.2) | 33.9 (±8.9) | 37.9 (±11.1) | 2.2 (±0.4) | 6.3 (±3.1) | No | Motor task |
| Kraft et al. (59) | 12 | 12 | 5/10 | 5/10 | 60.8 (±7.3) | 53.0 (±12.0) | 21.0 (±3.3) | 1.8 (±0.5) | 3.1 (±1.1) | No | Motor task |
| van der Stouwe et al. (60) | 12 | 18 | 7/9 | 8/7 | 59 (±9) | 59 (±5) | 21.5 (±6.9) | 1.9 (±0.5) | Not stated | No | Motor task |
| Wu et al. (61) | 15 | 15 | Not stated | Not stated | 59.73 (±8.27) | 60.3 | 20.67 (±3.48) | 1.7 (±0.37) | 3.47 (±1.6) | No | Motor task |
| Wurster et al. (62) | 10 | 10 | 7/14 | 7/12 | 66.4 (±7.2) | 64.9 (±8.14) | 20.7 (±9.1) | 2 (±0.83) | 6 (±5.6) | No | Motor task |
| Hughes et al. (63) | 16 | 15 | 11/10 | 11/11 | 63.9 (±7.5) | 66.5 (±5.9) | 31.3 (±11.) | 2.0 (±0.5) (ON) | 7.6 (±3.7) | No | Motor task |
| Lemos et al. (64) | 19 | 22 | 6/15 | 16/21 | 64.9 (±6.3) | 66.4 (±9.5) | Median: 19 (±19) | Median: 1.5 (±1) | 4 (±8) | No | Saccade task |
| Takeda et al. (65) | 9 | 7 | 5/4 | 5/2 | 54 | 51 | Not stated | 2.2 | Not stated | No | Sensory: olfactory |
| Tessitore et al. (66) | 20 | 18 | 9/11 | 8/10 | 60 (±8.9) | 55.9 (±5.2) | 10.1 (±7) | 1.4 (±0.5) | 1.2 (±0.5) | No | Sensory: pain |
| Harrington et al. (67) | 21 | 19 | 7/5 | 5/7 | 67 (±9.4) | 64.6 (±8.5) | 29.6 (±10.4) | 2 | Not stated | No | Working memory task |
| Snijders et al. (68) | 24 | 21 | 3/9 | 6/10 | 60.2 (±8.9) | 57.0 (±9.1) | 31.6 | Not stated | 8.45 | Yes | (Imagined) motor task |
| Maidan et al. (69) | 20 | 20 | 8/16 | 4/6 | 72.9 (±1.6) | 69.7 (±1.3) | 29.8 (±2.4) | Not stated | 6.8 (±1.3) | Yes | (Imagined) motor task |
| Baglio et al. (70) | 15 | 11 | 4/11 | 7/4 | 66.5 (±6.4) | 66.9 (±5.7) | 21.5 (±7.24) | 1.56 (±0.46) | Not stated | Yes | Cognitive: attention and inhibition |
| Labudda et al. (71) | 10 | 12 | 2/10 | 6/6 | 57.6 (±7.83) | 62.33 (±4.81) | Not stated | 3 | 7.1 (±3.7) | Yes | Cognitive: decision |
| Gescheidt et al. (72) | 18 | 18 | 4/14 | 7/11 | 52.67 | 50.61 | 18.89 | 1.97 | 6.33 | Yes | Cognitive: decision |
| Schonberg et al. (73) | 7 | 17 | 5/2 | 13/4 | 58.7 (±3.7) | 60 (±4.1) | 12.4 (±7.2) | 1.9 (±0.7) | 4 (±2.9) | Yes | Cognitive: error detection |
| Grossman et al. (74) | 7 | 9 | Not stated | Not stated | 71 (±10.2) | 65.7 (±10.2) | Not stated | 1 | Not stated | Yes | Cognitive: sentence comprehension |
| Ibarretxe-Bilbao et al. (75) | 24 | 24 | 8/16 | 8/16 | 56.13 (±8.5) | 57.58 (±8.9) | 14.67 (±3.5) | 1.73 (±0.4) | 3.06 (±1.6) | Yes | Cognitive: speech |
| Isaacs et al. (76) | 13 | 18 | 7/6 | 12/6 | 62.23 (±6.83) | 68.06 (±9.52) | Not stated | 1.46 (±0.52) | 5.39 (±3.8) | Yes | Cognitive: speech |
| Sachin et al. (77) | 8 | 6 | 3/8 | 4/8 | Not stated | Not stated | Not stated | Not stated | Not stated | Yes | Cognitive: speech |
| Nemcova et al. (78) | 16 | 55 | 4/75 | 38/17 | 62.7 (±6.8) | 66.7 (±7.3) | 16.8 (±9.1) | Not stated | 4.4 (±2.5) | Yes | Cognitive: visual object-matching task |
| Dan et al. (79) | 25 | 32 | 10/15 | 17/15 | 64.7 (±8.3) | 63.3 (±7.7) | 30.4 (±11.1) | 2 (±0.5) | 11.9 (±4.7) | Yes | Emotional recognition task |
| Pohl et al. (80) | 13 | 13 | 5/8 | 6/7 | Median: 68 | Median: 65 | 24.21 (±9.60) | Not stated | 5.94 (±4.39) | Yes | Emotional recognition task |
| Nombela et al. (81) | 10 | 10 | 9/14 | 10/13 | 60.5 (±3.45) | 59.6 (±4.47) | 22.2 (±7.9) | 2.5 (±0.5) | 8.1 (±2.0) | Yes | Executive functioning task |
| Rowe et al. (82) | 12 | 12 | 9/15 | 9/12 | 62 (±6) | 62 (±6) | 33.7 (±8.54) | 2.46 (±0.45) | 5.4 (±3.6) | Yes | Motor and attention task |
| Arnold et al. (83) | 20 | 20 | 8/12 | 8/12 | 63.9 | 64.2 | 26.1 | 1.65 | 5.8 | Yes | Motor and cognition task |
| Nieuwhof et al. (84) | 19 | 26 | 4/15 | 10/16 | 70.7 (±6.1) | 71.2 (±5.3) | 36.0 (±8.2) | 2 | 6.2 (±4.8) | Yes | Motor and cognition task |
| Zhao et al. (85) | 21 | 22 | Not stated | Not stated | 60.43 (±9.65) | 59.23 (±11.12) | 20.57 (±3.83) | 1.2 (±0.3) | 1.95 (±1.8) | Yes | Motor and sensory task |
| Sabatini et al. (86) | 6 | 6 | 2/4 | 2/4 | 61 (±8) | 59 (±19) | 16 (±4) | 2.7 (±0.5) | 5 (±2) | Yes | Motor task |
| Matt et al. (87) | 13 | 14 | 6/7 | 5/9 | 58.7 (±13) | 57.4 (±9.8) | 30.2 (±12.2) | 2.35 (±0.32) | 6.3 (±4.7) | Yes | Motor task |
| Tessa et al. (88) | 11 | 10 | 2/9 | 3/7 | 68 (±8) | 64 (±3.8) | 13.5 (±4.8) | 1.2 (±0.3) | 1.5 (±0.5) | Yes | Motor task |
| Hughes et al. (89) | 20 | 20 | 10/10 | 13/7 | 65.5 | 65.2 | 22.2 | 2.2 | Not stated | Yes | Motor task |
| Yan et al. (90) | 11 | 12 | 0/26 | 0/25 | 61.5 (±7.1) | 65.5 (±10.1) | 20.1 (±6.3) | Not stated | 4.9 (±3.9) | Yes | Motor task |
| van Eimeren et al. (91) | 20 | 10 | 9/11 | '5/5 | 50.3 (±7.8) | 50 (±8.7) | 21.95 (±13.6) | Not stated | 10.86 (±7.69) | Yes | Motor task |
| Spraker et al. (92) | 14 | 14 | '6/8 | (mached) | 57.2 (±9.6) | 57.6 | 18 (±8.1) | 1.7 (±0.45) | 16.5 (±10.8) | Yes | Motor task |
| Bedard et al. (34) | 10 | 10 | '5/5 | 8/2 | 57.4 (±8) | 62.4 (±10) | 14 (±7.8) | Not stated | Not stated | Yes | Motor, sensory- and learning |
| Westermann et al. (93) | 12 | 16 | 5/5 | '6/4 | 57.1 (±2.2) | 64.7 (±1.4) | Median: 28 | Median: 2 | Median: 3.3 | Yes | Sensory (olfactory) task |
| Lefebvre et al. (94) | 34 | 17 | 12/23 | 7/10 | 63.1 | 62.76 | 23.4 | 2 (±0.83) | 8.53 | Yes | Sensory (visual) task |
| Caminiti et al. (95) | 13 | 12 | 63.3 (±6.3) | 59 (±2.3) | NA | 1-2 | 5 (±3.4) | Yes | Working memory task | ||
| Simioni et al. (96) | 19 | 20 | 0/10 | 0/10 | 66 (±8.6) | 65 (±6.7) | 15.3 (±5.4) | 2.4 (±0.7) | 6.9 (±3.3) | Yes | Working memory task |
F, female; HC, healthy controls; M, male; PD, Parkinson's Disease; UPDRS, Unified Parkinson's Disease Rating Scale.