The brain's structural differences between postherpetic neuralgia and lower back pain.

Area of Science:

• Neuroscience
• Medical Imaging
• Pain Research

Background:

• Peripheral neuropathic pain (PNP) encompasses various chronic pain conditions.
• Understanding the distinct neural underpinnings of different PNP types is crucial for targeted treatment.

Purpose of the Study:

• To investigate structural brain differences in local morphology and network connectivity between lower back pain (LBP) and postherpetic neuralgia (PHN) patients.
• To identify specific brain regions and network alterations associated with each type of PNP.

Main Methods:

• Structural T1-weighted MRI scans were acquired from 54 participants (38 LBP, 16 PHN).
• Grey matter volume (GMV) and morphological connectivity (MC) were analyzed.
• Independent two-sample t-tests with FDR correction were employed to compare GMV and MC between LBP and PHN groups.

Main Results:

• LBP patients exhibited significantly larger GMV in the temporal gyrus, insula, and fusiform gyrus compared to PHN patients.
• LBP patients showed stronger MC between the right precuneus and left inferior frontal gyrus.
• Significant differences in network degree were observed in regions including the anterior cingulate cortex and supplementary motor area.

Conclusions:

• Lower back pain and postherpetic neuralgia demonstrate distinct structural brain alterations in grey matter volume and morphological connectivity.
• These findings highlight that different types of peripheral neuropathic pain involve unique neural mechanisms in pain modulation.