Recent discoveries have marked a turning point in our comprehension of the human brain.
A significant breakthrough occurred in 2024 when scientists uncovered direct evidence of a ‘waste disposal system’ within the human brain and spinal cord. Now, just a few years later, Australian researchers propose that this system might be linked to symptoms of a severe health condition affecting millions globally.
Their initial findings are detailed in Frontiers in Neuroscience.
Chronic fatigue syndrome, also known as myalgic encephalomyelitis (ME/CFS), has long been overlooked by the medical community, with no known cause or cure. Historically, when patients reported extreme fatigue, cognitive difficulties, or persistent flu-like symptoms, they were often dismissed as psychological issues. However, recent studies have identified clear biological markers of ME/CFS in patients’ genes, spinal fluid, blood, and gut microbiome.
Many of these markers are associated with the immune system or inflammation, indicating broader health concerns. Researchers at Griffith University in Australia now believe that a malfunctioning brain waste system may be the underlying cause.
“This study is the first to demonstrate impaired glymphatic function in ME/CFS using MRI, providing a mechanistic explanation for the inflammatory changes reported by other Australian and international teams,” says neuroimmunologist Kiran Thapaliya. “This suggests that dysfunction in the brain’s natural cleaning system may be a key driver of this condition.”
Although this research is small and preliminary, it is grounded in a sound hypothesis. The glymphatic system represents a new area in human physiology, and neuroscientists are just beginning to explore its complexities. Current understanding is largely based on mouse studies, suggesting that the brain’s recycling processes are most active during sleep. It’s believed that toxic substances or dead cells are cleared from the brain during this time, propelled by cerebrospinal fluid waves through a newly discovered plumbing network.
“Dysfunction in the brain’s natural cleaning system may be a key driver of this condition.” – neuroimmunologist Kiran Thapaliya
Research is beginning to link glymphatic system issues with cognitive decline, memory problems, musculoskeletal issues, and psychosis. This study is the first to explore a connection with ME/CFS. In their investigations, Thapaliya and colleagues conducted brain scans on 31 ME/CFS patients, comparing them with 27 healthy controls. Visualizing the glymphatic system is challenging, which is why it has remained elusive for so long.
Traditionally, this requires injecting a tracer into the cerebrospinal fluid (CSF) in a complex procedure to visualize its flow through the brain’s hidden pathways.
However, Griffith researchers adopted a different approach. They employed a non-invasive technique that estimates glymphatic function by measuring the diffusion rate of CSF into tiny channels around small blood vessels in the brain. While less direct and precise, this method can non-invasively assess MRI scans. This technique has already suggested glymphatic flow changes in patients with Parkinson’s disease, Alzheimer’s, blood pressure issues, and multiple sclerosis.
Australian researchers have now identified signs of reduced glymphatic function in the brain scans of CFS/ME patients. Notably, this dysfunction is limited to the brain’s right hemisphere.
“This kind of hemispheric asymmetry,” the study authors note, “has been previously reported in patients with temporal lobe epilepsy, Parkinson’s disease, and amyotrophic lateral sclerosis (ALS).”
Interestingly, the severity of sleep problems or cognitive difficulties in CFS/ME patients correlates with greater signs of glymphatic dysfunction in the right hemisphere.
Sonya Marshall-Gradisnik, director of the National Center for Neuroimmunology and Emerging Diseases at Griffith, explains that these brain scans underscore “the notion that sleep plays a critical role in maintaining brain health.” She adds, “We hope the results can pave the way for better diagnosis through the use of non-invasive procedures, and importantly, future treatment for patients.”
Unfortunately, the study does not explain why glymphatic dysfunction might occur only in the right hemisphere or how it could drive CFS/ME symptoms.
If the brain’s waste clearance system fails to remove toxic substances, it could exacerbate inflammation in the central nervous system, leading to neurological symptoms. This is a similar argument for why the glymphatic system may be disrupted in Alzheimer’s or Parkinson’s disease.
Extensive research is needed to fully understand the glymphatic system in human brains and how its disruption might contribute to various diseases.
Related: Scientists Mapped The Human Brain’s Sewage System For The First Time
The discovery of the glymphatic system could revolutionize neuroscience. What was once considered waste is now seen as a valuable insight into neurological health.
The study is available in Frontiers in Neuroscience.
This article was fact-checked by Michael Irving and edited by Peter Dockrill. While we pride ourselves on our process, we are only human. If you spot a mistake, please let us know.
