Greater loss of white matter integrity in postural instability and gait difficulty subtype of Parkinson's disease.
BACKGROUND
Patients with the postural instability and gait difficulty (PIGD) subtype of Parkinson disease (PD) are at a higher risk of dysfunction and are less responsive to dopamine replacement therapy. The PIGD subtype was found to largely associate with white matter lesions, but details of the diffusion changes within these lesions have not been fully investigated. Voxel-based analysis for diffusion tensor imaging data is one of the preferred measures to compare diffusion changes in each voxel in any part of the brain.


METHODS
PD patients with the PIGD (n=12) and non-PIGD subtypes (n=12) were recruited to compare diffusion differences in fractional anisotropy, axial diffusivity, and radial diffusivity with voxel-based analysis.


RESULTS
Significantly reduced fractional anisotropy in bilateral superior longitudinal fasciculus, bilateral anterior corona radiata, and the left genu of the corpus callosum were shown in the PIGD subtype compared with the non-PIGD subtype. Increased radial diffusivity in the left superior longitudinal fasciculus was found in the PIGD subtype with no statistical differences in axial diffusivity found.


CONCLUSIONS
Our study confirms previous findings that white matter abnormalities were greater in the PIGD subtype than in the non-PIGD subtype. Additionally, our findings suggested: (1) compared with the non-PIGD subtype, loss of white matter integrity was greater in the PIGD subtype; (2) bilateral superior longitudinal fasciculus may play a critical role in microstructural white matter abnormalities in the PIGD subtype; and (3) reduced white matter integrity in the PIGD subtype could be mainly attributed to demyelination rather than axonal loss.
1Department of Radiology,the Second Affiliated Hospital,Zhejiang University School of Medicine,Hangzhou,China.
Quanquan
Q
Gu
1Department of Radiology,the Second Affiliated Hospital,Zhejiang University School of Medicine,Hangzhou,China.
Peiyu
P
Huang
1Department of Radiology,the Second Affiliated Hospital,Zhejiang University School of Medicine,Hangzhou,China.
Min
M
Xuan
1Department of Radiology,the Second Affiliated Hospital,Zhejiang University School of Medicine,Hangzhou,China.
Xiaojun
X
Xu
2Department of Neurology,the Second Affiliated Hospital,Zhejiang University School of Medicine,Hangzhou,China.
Dan
D
Li
1Department of Radiology,the Second Affiliated Hospital,Zhejiang University School of Medicine,Hangzhou,China.
Jianzhong
J
Sun
3Department of Psychiatry,the Second Affiliated Hospital,Zhejiang University School of Medicine,Hangzhou,China.
Hualiang
H
Yu
1Department of Radiology,the Second Affiliated Hospital,Zhejiang University School of Medicine,Hangzhou,China.
Chao
C
Wang
2Department of Neurology,the Second Affiliated Hospital,Zhejiang University School of Medicine,Hangzhou,China.
Wei
W
Luo
1Department of Radiology,the Second Affiliated Hospital,Zhejiang University School of Medicine,Hangzhou,China.
Minming
M
Zhang
D005260:Female; D020233:Gait Disorders, Neurologic / Q000150:complications* / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications* / Q000175:diagnosis*; D004856:Postural Balance / Q000502:physiology; D066127:White Matter / Q000473:pathology*