Dissecting neuropathic from poststroke pain: the white matter within

Area of Science:

• Neuroscience
• Neurology
• Radiology

Background:

• Poststroke pain (PSP) is complex, including central neuropathic (CPSP) and nonneuropathic (CNNP) types.
• CPSP is often linked to specific brain lesions, but the role of connecting white matter is understudied.
• The relationship between stroke location and CNNP requires further clarification.

Purpose of the Study:

• To compare stroke locations in patients with CPSP, CNNP, and no pain.
• To investigate the role of white matter lesions in the development of CPSP.
• To identify brain regions and connections associated with an increased risk of CPSP.

Main Methods:

• Voxel-wise lesion symptom mapping (VLSM) on brain MRI scans.
• Region of interest (ROI)-based analysis to confirm known CPSP sites.
• Calculation of odds ratio maps to quantify CPSP risk associated with specific lesions.

Main Results:

• Beyond thalamic and parietoinsular areas, significant CPSP risk was found in white matter connecting thalamocortical regions.
• Lesions in these thalamoinsular white matter connections significantly increased CPSP risk (OR=39.7).
• These findings contrast with stroke locations observed in CNNP and stroke patients without pain.

Conclusions:

• Interruption of thalamocortical white matter connections is a key factor in CPSP.
• Identifying these specific white matter lesions can help predict patients at risk for CPSP.
• This knowledge may guide pre-emptive or therapeutic interventions for poststroke pain.