Abnormal alterations in structure-function coupling at the modular level in patients with postherpetic neuralgia

Area of Science:

• Neuroscience
• Medical Imaging
• Network Science

Background:

• Postherpetic neuralgia (PHN) is a chronic pain condition with complex neurological underpinnings.
• Understanding brain network alterations in PHN is crucial for developing targeted therapies.

Purpose of the Study:

• To investigate modular loss of coupling and abnormal alterations in functional and structural brain networks in PHN patients.
• To correlate these network changes with clinical pain and psychological assessments.

Main Methods:

• Collected resting-state functional MRI and diffusion tensor imaging data from 71 PHN patients and 82 healthy controls.
• Generated structural connectivity (SC) and functional connectivity (FC) networks, analyzed topological properties using graph theory, and assessed SC-FC coupling across 9 brain modules.
• Performed correlation analyses with Visual Analogue Scale (VAS), Hamilton Anxiety Scale (HAMA), and Hamilton Depression Scale (HAMD).

Main Results:

• PHN patients exhibited reduced global and local efficiency in both SC and FC networks compared to controls.
• Abnormalities in node properties (degree, clustering coefficient, efficiency) were observed in both SC and FC networks.
• Significant reduction in SC-FC coupling was found in the default mode network (DMN), salient network (SN), and visual network (VIS).
• Impaired graph theory metrics correlated positively with VAS scores, while module coupling correlated negatively with disease duration.

Conclusions:

• PHN is associated with widespread disruptions in brain network topology and significant structural-functional decoupling.
• These aberrant network alterations, especially in the DMN, SN, and VIS, may contribute to pain hypersensitivity and central sensitization in PHN.
• Network analysis provides potential biomarkers for PHN severity and disease course.