JANUARY 9, 2024
Chronic pain, which activates microglia and thus inflammation in the brain, could lead to cognitive decline and dementia, according to a recent study.
“Our findings suggest that chronic pain is biologically linked to detrimental brain changes leading to degeneration, and potentially dementia,” study researcher Robert Perneczky, MD, the chair in Translational Dementia Research at the Sheffield Institute for Translational Neuroscience, in Sheffield, England, told Pain Medicine
Chronic pain, which activates microglia and thus inflammation in the brain, could lead to cognitive decline and dementia, according to a recent study.
“Our findings suggest that chronic pain is biologically linked to detrimental brain changes leading to degeneration, and potentially dementia,” study researcher Robert Perneczky, MD, the chair in Translational Dementia Research at the Sheffield Institute for Translational Neuroscience, in Sheffield, England, told Pain Medicine News.
Researchers classified 995 individuals (mean age, 73.07 years; 56.28% male,) using ATN classification (amyloid, tau, neurodegeneration) which identifies risk for neurodegenerative disease (Ann Neurol 2023 Oct 3. doi: 10.1002/ana.26804). Nearly 61% of the participants reported chronic pain at baseline. Patients were then classified into four groups: subjects with signs of Alzheimer’s disease (A+TN+ and A+TN−), those who had normal biomarkers (A−TN−), and patients suspected of non-Alzheimer’s pathophysiology who had signs of inflammation and neurodegeneration (A−TN+).
For each ATN group, differences in cerebrospinal fluid levels of amyloid beta1–42, phosphorylated tau 181 (ptau181), total tau (t-tau), soluble triggering receptor expressed on myeloid cells 2 (sTREM2), and cognitive function between chronic pain states were analyzed.
Chronic pain was associated with increased tumor necrosis factor-alpha levels (a sign of activated microglia), irrespective of ATN group. Individuals with suspected non-Alzheimer’s pathophysiology and chronic pain showed increased cerebrospinal fluid levels of t-tau (a protein that is thought to indicate the intensity of neuronal damage in neurodegeneration) and sTREM2 (associated with risk for cognitive decline). No significant longitudinal decline in cognitive function was observed for any ATN group.
“From a clinical perspective, [this study shows us that] it is important to effectively treat pain in older individuals, not only to increase their quality of life, but also to protect their brains,” Perneczky noted.
Due to a limited number of patients with chronic pain in the study cohort, the researchers could not specifically explore the effects of pain severity and duration on biomarkers of neural damage. “Next steps would include following patients over longer periods of time to investigate how biological and cognitive findings change over time, and to explore the effect of anti-inflammatory medication on the observed associations,” Perneczky concluded.
—Myles Starr
Perneczky reported no relevant financial disclosures.
