Beijing, Feb 22 (IANS): People living with chronic pain conditions in the knee, neck and back due to ailments such as arthritis or cancer may be at a higher risk of developing dementia, claimed a study.

The research from the Chinese Academy of Sciences showed that people with chronic pain in multiple parts of the body experienced broader and faster cognitive decline, including memory, executive function, learning and attention.

Multisite chronic pain, where pain is experienced in multiple anatomical locations, affects almost half of chronic pain patients and has been found to place a greater burden on patients' overall health.

However, it was not clear whether people with multisite chronic pain suffered from aggravated neurocognitive abnormalities.

To understand, the new study, published online in the journal PNAS, analysed the records of 354,943 people. It found that the risk of neurocognitive abnormality increased with each additional pain site.

It was also mediated by atrophy in the hippocampus, the part of the brain responsible for memory.

"Multisite chronic pain may lead to up to eight years of accelerated hippocampal ageing, an effect that may underlie a series of cognitive burdens," said Dr. TU Yiheng from the Academy's Institute of Psychology.

Since hippocampal volume decreases with age, the researchers equated the magnitude of the effect of hippocampal atrophy in patients with multisite chronic pain to the effect of ageing in healthy people with an average age of 60.

The study provides a quantitative understanding of the impact of chronic pain on cognitive function and the risk of dementia, laying an important foundation for future research into the relationship between chronic pain and cognitive impairment.

It also highlights the excessive burden of multisite chronic pain on patients' cognition and the brain, and the need to address the overlapping nature of pain conditions in both basic research and clinical studies.