Table 2.

Fixel-Based Analysis in White Matter Tracts.

Tract of Interest	P-value FDR corrected	P-value uncorrected	F	Partial Eta Squared
Fibre Density (FD)
M1 TCATT	0.022d	0.007	4.350	0.145
PMd TCATT	0.020d, e	0.007	4.400	0.146
PMv TCATT	0.020d, e	0.006	4.487	0.149
preSMA TCATT	0.020d, e, f	0.004	4.923	0.161
SMA TCATT	0.088	0.078	2.362	0.084
S1 TCATT	0.033d	0.021	3.435	0.118
M1 SMATT	0.020a, b, d	0.005	4.556	0.151
PMd SMATT	0.032b, c, d	0.019	3.531	0.121
PMv SMATT	0.046d	0.035	3.013	0.105
preSMA SMATT	0.032b	0.018	3.540	0.121
SMA SMATT	0.021b, c, d	0.010	4.061	0.137
S1 SMATT	0.046b	0.033	3.074	0.107
Nigrostriatal	0.087	0.072	2.420	0.086
Corticostriatal	0.020a, b, d	0.004	4.791	0.157
STN to GP	0.021e, f	0.010	4.058	0.137
MCP	0.167	0.157	1.787	0.065
SCP	0.210	0.210	1.544	0.057
Fibre Cross-section (log FC)
M1 TCATT	0.300	0.105	2.116	0.076
PMd TCATT	0.193	0.034	3.034	0.106
PMv TCATT	0.300	0.159	1.777	0.065
preSMA TCATT	0.300	0.107	2.101	0.076
SMA TCATT	0.193	0.026	3.247	0.112
S1 TCATT	0.377	0.355	1.098	0.041
M1 SMATT	0.300	0.194	1.608	0.059
PMd SMATT	0.307	0.231	1.463	0.054
PMv SMATT	0.667	0.667	0.524	0.020
preSMA SMATT	0.307	0.267	1.343	0.050
SMA SMATT	0.300	0.194	1.608	0.059
S1 SMATT	0.307	0.271	1.329	0.049
Nigrostriatal	0.300	0.081	2.331	0.083
Corticostriatal	0.300	0.168	1.730	0.063
STN to GP	0.300	0.144	1.857	0.067
MCP	0.307	0.270	1.334	0.049
SCP	0.193	0.024	3.333	0.115
Fibre Density and Cross-section (FDC)
M1 TCATT	0.140	0.114	2.046	0.074
PMd TCATT	0.075	0.009	4.160	0.139
PMv TCATT	0.075	0.020	3.469	0.119
preSMA TCATT	0.104	0.043	2.855	0.100
SMA TCATT	0.088	0.031	3.119	0.108
S1 TCATT	0.419	0.394	1.008	0.038
M1 SMATT	0.140	0.115	2.045	0.074
PMd SMATT	0.121	0.078	2.356	0.084
PMv SMATT	0.440	0.440	0.911	0.034
preSMA SMATT	0.106	0.050	2.728	0.096
SMA SMATT	0.121	0.076	2.385	0.085
S1 SMATT	0.149	0.131	1.933	0.070
Nigrostriatal	0.075	0.011	3.937	0.133
Corticostriatal	0.140	0.113	2.058	0.074
STN to GP	0.075	0.015	3.730	0.127
MCP	0.075	0.022	3.377	0.116
SCP	0.121	0.073	2.412	0.086

ANOVA results for main effect of group with age, sex, and site covariates.

Bold type indicates statistically significant values. Superscripts indicate significant post-hoc comparisons (P < 0.05, FDR-corrected).

TCATT: trans callosal tractography template, SMATT: sensorimotor area tract template, M1: Primary motor cortex, PMd: dorsal Premotor area, PMv: ventral Premotor area, SMA: supplementary motor area, S1: Primary sensory cortex, STN: subthalamic nucleus, GP: globus pallidus, MCP: middle cerebellar peduncle, SCP: superior cerebellar peduncle.

^aPD vs. Controls.

^bMSAp vs. Controls.

^cMSAp vs. PD.

^dPSP vs. Controls.

^ePSP vs. PD.

^fMSAp vs. PSP.