Table II.

SPM results of grey matter analysis

P(FWE)	P(FWE/ cluster)	k	T	MNI	Atlas
IPS < controls
0.949	0.715	163	3.8	2 −48 72	Right precuneus
			3.4	−9 −60 72
IPS > controls
No clusters
MSA‐P < IPS
0.921	0.911	89	4	21 3 6	Right putamen
MSA‐P > IPS
0.577	0.731	161	4.5	24 −42 69	Right superior parietal lobule
0.737	0.96	61	4.3	2 −73 49	Right precuneus
			3.5	0 −69 37
0.839	0.481	258	4.2	−6 −49 67	Left precuneus
			3.9	−16 −46 64
			3.7	−9 −58 69
PSP < IPS
0.047	<0.001	5101	5.9	16 −39 −30	(Right cerebellum)
			5.3	15 −61 −20
			5.3	22 −57 −17
0.158	<0.001	4216	5.4	−28 −76 −36	(Left cerebellum)
			5.3	−20 −70 −23
			4.3	−42 −78 −33
0.826	0.84	118	4.3	14 −91 37	Right occiptal pole
0.895	0.948	71	4.2	54 5 21	right precentral gyrus
0.984	0.953	68	3.9	16 −46 −45	(Right cerebellum)
PSP > IPS
0.498	0.923	84	4.7	−14 −57 72	Left lateral occipital cortex, superior division
0.971	0.516	229	3.9	22 −45 69	Right superior parietal lobule
MSA‐P > PSP
No clusters
MSA‐P < PSP
No clusters

Clusters and local maxima (more than 8 mm apart) of the grey 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 Harvard‐Oxford Cortical/Subcortical Structural Atlas; only the structure with the highest probability is reported. When no label was found in the atlas, the region was estimated visually and printed in brackets.

IPS, idiopathic Parkinson syndrome; MSA‐P, multiple systems atrophy (parkinsonian variant); PSP, progressive supranuclear palsy. k = size of the cluster in voxels.