Table III.

SPM results of white matter analysis

P (FEW)	P (FWE/ cluster)	k	T	MNI	Atlas
IPS < controls
No clusters
IPS > controls
0.465	0.798	90	4.1	52 −46 25	Right superior longitudinal fasciculus/right angular gyrus
MSA‐P < IPS
0.522	0.78	103	4.3	14 −15 75	Right corticospinal tract/right precentral gyrus
0.73	0.468	246	4.0	32 −7 −0	Right external capsule/right putamen
0.868	0.843	76	3.8	−20 −27 73	Left corticospinal tract/Left precentral gyrus
MSA‐P > IPS
No clusters
PSP < IPS
<0.001	<0.001	19,990	8.6	−2 −21 −2	Left anterior thalamic radiation/left thalamus
			8.4	−2 −19 −11
			6.7	2 −43 −30
PSP > IPS
0.237	0.803	95	4.8	10 −45 64	No label found/right postcentral gyrus
MSA‐P > PSP
0.087	<0.001	5,032	6.3	0 −21 0	No label found/midline thalamus
			5.8	0 −16 −11
			5.2	−12 −10 12
MSA‐P < PSP
No clusters

Clusters and local maxima (more than 8 mm apart) of the white matter SPM analysis thresholded at p<0.001 (uncorrected) are shown. Peak and cluster level corrected P values (FWE) are also displayed. Clusters surviving peak level FWE correction are printed in bold. Anatomical position was determined using FSL view atlas tools and the JHU White‐Matter Tractography (first label) and Harvard‐Oxford Cortical/Subcortical Structural Atlas (second label); only the structure with the highest probability is reported. IPS, idiopathic Parkinson syndrome; MSA‐P, multiple systems atrophy (parkinsonian variant); PSP, progressive supranuclear palsy. k = size of the cluster in voxels.