Altered homotopic connectivity in postherpetic neuralgia: a resting state fMRI study.
OBJECTIVE
The aim of this study was to explore interhemispheric intrinsic connectivity in patients with postherpetic neuralgia (PHN).


METHODS
We obtained resting-state functional magnetic resonance imaging data from 18 right-handed PHN patients (11 males, 7 females; mean age, 59.67±8.41 years) and 18 well-matched healthy controls (11 males, 7 females; mean age, 38.50±7.51 years). Interhemispheric connectivity was examined using voxel-mirrored homotopic connectivity (VMHC), and seed-based functional connectivity analysis was performed.


RESULTS
Compared with the healthy controls, the patients with PHN showed abnormally decreased homotopic connectivity in the dorsolateral prefrontal cortex and the precuneus and posterior cingulate cortex (PCUN/PCC). The decreased VMHC in the PCUN/PCC was positively correlated with the visual analog scale of PHN in the PHN patient group (ρ=0.651;P=0.006). Receiver operating characteristic (ROC) analysis revealed that the areas under the curves for the two brain regions were 0.898 for the prefrontal cortex and 0.923 for the PCUN/PCC, which indicated that the VMHC could be used to discriminate PHN patients from healthy controls. A subsequent seed-based functional connectivity analysis revealed widely disrupted intrinsic connectivity between the regions that showed local homotopic connectivity deficits and the areas subserving the default-mode network.


CONCLUSIONS
Our results indicated reduced interhemispheric functional connectivity in patients with PHN, which seems to be an important new avenue to investigate to better understand the nature of disconnection of the functional architecture in patients with PHN.
Department of Radiology.
Jian
J
Jiang
Department of Pain, The First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi, People's Republic of China.
Lili
L
Gu
Department of Pain, The First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi, People's Republic of China.
Dan
D
Bao
Department of Radiology.
Shunda
S
Hong
Department of Radiology.
Wei
W
He
Department of Radiology.
Yonming
Y
Tan
Department of Radiology.
Xianjun
X
Zeng
Department of Radiology.
Honghan
H
Gong
Department of Pain, The First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi, People's Republic of China.
Daying
D
Zhang
Department of Radiology.
Fuqing
F
Zhou
functional magnetic resonance imaging; pain; postherpetic neuralgia; resting state; voxel-mirrored homotopic connectivity