Involvement of Reorganization of Cerebral Functional Connectivity in the Process of Transition to Postherpetic Neuralgia

Postherpetic neuralgia(PHN) is a chronic neuropathic pain syndrome which persists more than 3 months after the resolution of the acute shingles episode. PHN is a complicated neuropathic pain that results from the sustained peripheral injury by herpes zoster and its pathological mechanism in skin and spine has been reported. But the cerebral mechanism is still unclear. Based on the previous study that has proved the reorganization of cerebral functional connectivity in pain chronicity, the investigators hypothesize that the process from acute herpetic pain (AHP) to PHN is also accompanied with the reorganization of functional connectivity.In the study, the investigators intend to use 7 Tesla functional magnetic resonance imaging(fMRI) to observe the difference of brain activity and functional connectivity between acute herpetic pain and PHN. Meanwhile, the investigators examine the evolution of functional connectivity longitudinally in patients who is suffering from acute pain, so as to explore the central mechanism of transition to PHN.