By Michelle Jaffee
New research led by University of Florida neuroscientists shows chronic pain may affect the brain’s ability to clear waste in people with worse sleep. The waste-removal process, which normally occurs during sleep, is vital to brain health and fending off conditions such as Alzheimer’s disease.
The new study assessed 87 participants with chronic knee pain over two years. Researchers combined survey responses on levels of pain and sleep impairment with results from an advanced MRI technique considered to be one indicator of activity of the glymphatic system, important for flushing out waste during sleep.
Published in The Journal of Pain, the study found that participants who reported more widespread and prolonged pain showed significant changes on a specific MRI measure of the glymphatic system, called DTI-ALPS, but only if they also reported worse sleep quality over time.
“This finding is the first to show impaired waste clearance in the brain in people with chronic pain over time and highlights the brain’s role in the pain-sleep relationship,” said Yenisel Cruz-Almeida, MSPH, Ph.D., the study’s lead author and a McKnight Brain Institute investigator.
Changes in the brain’s left hemisphere shown on DTI-ALPS indicate lower capacity for clearing waste, a process that mostly occurs during slow-wave sleep, the researchers reported.
The results show potential for using MRI to advance understanding of chronic pain’s impact on brain health, said Cruz-Almeida, who is the associate director of UF’s Pain Research & Intervention Center of Excellence and an associate professor in the UF College of Dentistry.
“Our findings suggest that getting good quality sleep may help keep the brain healthy, despite the pain,” she said. “Our future studies will test other measures of glymphatic function, opening new avenues for pain treatment and brain health.”
The research was carried out at the MBI’s Advanced Magnetic Resonance Imaging and Spectroscopy Facility (AMRIS) and the University of Alabama at Birmingham.