The following is a summary of “Association of chronic pain with biomarkers of neurodegeneration, microglial activation and inflammation in the CSF and impaired cognitive function,” published in the October 2023 issue of Neurology by Sadlon et al.

The potential role of chronic pain as a risk factor for cognitive decline and dementia is a topic of debate. Researchers started a retrospective study to investigate the association of chronic pain with neurodegeneration biomarkers using Alzheimer’s Disease Neuroimaging Initiative (ADNI) data.

They classified participants using the ATN classification, with chronic pain as persistent or recurrent pain reported at baseline. ANCOVA models were used to identify differences in CSF levels of Aβ _1-42, ptau₁₈₁, t-tau, sTREM2, and cognitive function between chronic pain states for each ATN group. CSF levels of inflammatory markers in chronic pain states were analyzed. Longitudinal changes were examined using linear mixed-effect models.

The results indicated that individuals with suspected non-Alzheimer’s pathophysiology (SNAP) and chronic pain had elevated CSF levels of t-tau and sTREM2 at baseline. Regardless of the ATN group, chronic pain was linked to increased TNF-α levels. Over time, chronic pain patients with harmful amyloid and neurodegeneration markers experienced an increase in ptau ₁₈₁ CSF levels. Amyloid-positive and neurodegeneration-negative chronic pain patients exhibited better memory function in cross-sectional analysis. No significant longitudinal decline in cognitive function was observed for any ATN group.

Investigators concluded that chronic pain may induce neuronal damage and microglial activation in some AD patients.

Source: onlinelibrary.wiley.com/doi/abs/10.1002/ana.26804