Table 3.
Subgroup analysis based on the type of tau tracer used for studies involving PD and HCs subjects.
Region | Tracer | Number of studies | Subjects | SMD | [95% CI] | Overall effect | Heterogeneity | |||
---|---|---|---|---|---|---|---|---|---|---|
PD | HCs | Z | P | I 2 [%] | P | |||||
Global | 1st generation | 3 | 58 | 43 | −0.102 | [−0.69, 0.49] | −0.34 | 0.735 | 45.0 | 0.163 |
2nd generation | 0 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | |
Frontal lobe | 1st generation | 4 | 38 | 33 | −0.39 | [−1.31, 0.52] | −0.847 | 0.397 | 68.7 | 0.022 |
2nd generation | 1 | 10 | 13 | −0.37 | [−1.20, 0.47] | −0.862 | 0.389 | N/A | N/A | |
Prefrontal lobe | 1st generation | 2 | 27 | 40 | −0.19 | [−0.69, 0.30] | −0.760 | 0.447 | 0 | 0.461 |
2nd generation | 1 | 6 | 10 | 0.07 | [−0.94, 1.09] | 0.142 | 0.887 | N/A | N/A | |
Parietal lobe | 1st generation | 5 | 49 | 65 | −0.08 | [−0.70, 0.54] | −0.253 | 0.801 | 58.1 | 0.049 |
2nd generation | 1 | 10 | 13 | −0.10 | [−0.93, 0.72] | −0.240 | 0.811 | N/A | N/A | |
Sub.parietal lobe | 1st generation | 2 | 49 | 40 | 0.128 | [−0.29, 0.55] | 0.60 | 0.551 | 0 | 0.442 |
2nd generation | 0 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | |
Inf.parietal lobe | 1st generation | 2 | 49 | 40 | 0.122 | [−0.30, 0.54] | 0.57 | 0.567 | 0 | 0.950 |
2nd generation | 0 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | |
Occipital lobe | 1st generation | 3 | 57 | 50 | 0.072 | [−0.31, 0.45] | −0.302 | 0.763 | 0 | 0.961 |
2nd generation | 1 | 10 | 13 | 0 | [−0.82, 0.82] | 0 | 1.000 | N/A | N/A | |
Lat.temporal lobe | 1st generation | 2 | 24 | 13 | 0.35 | [−0.33, 1.04] | 1.013 | 0.311 | 0 | 0.391 |
2nd generation | 1 | 10 | 13 | −0.21 | [−1.04, 0.61] | −0.504 | 0.614 | |||
Med.temporal lobe | 1st generation | 2 | 24 | 13 | −1.21 | [−1.95, −0.47] | −3.221 | 0.001 | 0 | 0.836 |
2nd generation | 0 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | |
Sup.temporal lobe | 1st generation | 3 | 75 | 63 | −0.18 | [−0.52, 0.16] | −1.05 | 0.294 | 0 | 0.392 |
2nd generation | 0 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | |
Mid.temporal lobe | 1st generation | 2 | 49 | 40 | 0.056 | [−0.364, 0.475] | 0.26 | 0.795 | 0 | 0.481 |
2nd generation | 0 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | |
Inf.temporal lobe | 1st generation | 4 | 159 | 227 | 1.09 | [−0.11, 2.28] | 1.78 | 0.074 | 94.7 | 0 |
2nd generation | 0 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | |
Caudate nucleus | 1st generation | 3 | 47 | 71 | −0.20 | [−0.62, 0.22] | −0.948 | 0.343 | 13.5 | 0.315 |
2nd generation | 1 | 10 | 13 | 0 | [−0.82, 0.82] | 0 | 1.000 | N/A | N/A | |
Putamen | 1st generation | 4 | 46 | 76 | −0.15 | [−0.52, 0.22] | −0.791 | 0.429 | 0 | 0.725 |
2nd generation | 2 | 16 | 23 | 0.58 | [−0.07, 1.24] | 1.747 | 0.081 | 0 | 0.986 | |
Globus pallidus | 1st generation | 5 | 81 | 104 | −0.36 | [−0.66, −0.06] | −2.38 | 0.017 | 0 | 0.699 |
2nd generation | 2 | 16 | 23 | 0.47 | [−0.18, 1.12] | 1.431 | 0.152 | 0 | 0.999 | |
Thalamus | 1st generation | 3 | 29 | 30 | −0.18 | [−0.70, 0.34] | −0.675 | 0.500 | 0 | 0.721 |
2nd generation | 1 | 10 | 13 | 0.06 | [−0.77, 0.88] | 0.141 | 0.888 | N/A | N/A | |
Subthalamic nucleus | 1st generation | 3 | 49 | 66 | −0.09 | [−0.85, 0.66] | −0.243 | 0.808 | 67.7 | 0.045 |
2nd generation | 2 | 16 | 23 | 0.31 | [−0.33, 0.96] | 0.950 | 0.342 | 0 | 0.488 | |
Midbrain | 1st generation | 1 | 8 | 5 | −0.62 | [−1.77, 0.53] | −1.060 | 0.289 | N/A | N/A |
2nd generation | 2 | 16 | 23 | 0.19 | [−0.45, 0.83] | 0.570 | 0.568 | 0 | 0.671 | |
Substantia nigra | 1st generation | 4 | 73 | 94 | −1.18 | [−1.52, −0.85] | −6.890 | 0 | 0 | 0.941 |
2nd generation | 2 | 16 | 23 | 0.13 | [−0.51, 0.77] | 0.396 | 0.692 | 0 | 0.624 | |
Dentate nucleus | 1st generation | 3 | 47 | 71 | 0.05 | [−0.32, 0.42] | 0.254 | 0.799 | 0 | 0.626 |
2nd generation | 2 | 16 | 23 | −0.15 | [−0.79, 0.49] | −0.470 | 0.638 | 0 | 0.700 | |
Entorhinal | 1st generation | 4 | 168 | 223 | −0.12 | [−0.33, 0.08] | −1.18 | 0.237 | 0 | 0.852 |
2nd generation | 0 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | |
Hippocampus | 1st generation | 3 | 75 | 63 | −0.50 | [−0.84,−0.16] | −2.86 | 0.004 | 0 | 0.995 |
2nd generation | 0 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | |
Precuneus | 1st generation | 4 | 84 | 92 | 0.37 | [−0.3, 1.05] | 1.08 | 0.278 | 77.3 | 0.004 |
2nd generation | 0 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | |
Post.cingulate | 1st generation | 4 | 73 | 53 | −0.38 | [−0.88, 0.12] | 1.48 | 0.138 | 39.7 | 0.174 |
2nd generation | 0 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | |
Ant.cingulate | 1st generation | 2 | 49 | 40 | −0.16 | [−0.58, 0.26] | −0.76 | 0.448 | 0 | 0.648 |
2nd generation | 0 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | |
Sensorimotor | 1st generation | 2 | 49 | 40 | 0.067 | [−0.35, 0.49] | 0.31 | 0.755 | 0 | 0.822 |
2nd generation | 0 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | |
Insula | 1st generation | 2 | 49 | 40 | −0.15 | [−0.57, 0.27] | 0.71 | 0.477 | 0 | 0.888 |
2nd generation | 0 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | |
Amygdala | 1st generation | 2 | 49 | 40 | −0.32 | [−0.74, 0.10] | 1.48 | 0.14 | 0 | 0.732 |
2nd generation | 0 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
PD, Parkinson's disease; HCs, healthy controls; SMD, Standardized mean difference; CI, confidence interval; N/A, Not applicable. The bold values indicate the value of P < 0.05.