In a world-first study, Queensland researchers have identified similar changes in brain structure among people who have long COVID and chronic fatigue syndrome.
Griffith University scientists used a high-powered magnetic resonance imaging scanner to compare the brains of 28 adults.
Eight had long COVID, 10 people had been diagnosed with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and 10 were healthy volunteers.
The researchers, from Griffith's National Centre for Neuroimmunology and Emerging Diseases, found the brainstem was significantly larger in long COVID patients and those with ME/CFS compared to people who had never been diagnosed with either ailment.
"Structural changes in the brain stem of ME/CFS and long COVID patients could result in severe and varied deficits in brain function," they wrote in a study published in the journal, Frontiers in Neuroscience.
"The symptom overlap between ME/CFS and long COVID patients is consistent with our current findings of similar abnormalities in the brainstem."
Lead researcher Kiran Thapaliya said brain stem similarities in people with long COVID and ME/CFS patients may explain why they exhibited common core symptoms, such as brain fog, fatigue, pain and breathing difficulties.
Dr Thapaliya, a Griffith University research fellow, said the researchers were recruiting more people to continue to investigate the findings of their pilot study in a larger number of patients with long COVID and ME/CFS.
They used a high-resolution MRI machine at the University of Queensland's Centre for Advanced Imaging for the pilot study.
"This specialised MRI provides crisp images and also greater detailed information … and uncovered abnormalities that might not be detected in other MRIs," Dr Thapaliya said.
Professor Sonya Marshall-Gradnisnik, director of Griffith's National Centre for Neuroimmunology and Emerging Diseases, said the purpose of the study was to demonstrate potential consistencies between ME/CFS and long COVID patients.
The research comes seven months after Griffith University researchers reported a shared link in the pathology of long COVID and ME/CFS.
In the first study of its kind in the world to identify a biological overlap between the two conditions, they reported similar damage to receptors on cells – described as like a dysfunctional lock and key – which fail to allow enough calcium in.
"Patients can experience different symptoms depending on which cells in the body are affected – from brain fog and muscle fatigue to possible organ failure," Professor Marshall-Gradnisnik has said previously.
'Scary' impact of long COVID
Disability support worker Sue Murphy developed long COVID after contracting the pandemic virus in January last year.
The 63-year-old, who welcomed research into the malady, has been off work since then with debilitating symptoms, including fatigue, heart problems, breathlessness, migraines and muscle pain.
She's had brain fog so bad she had to pull over on the way home after having some blood tests and scans because she "could not recognise where I was".
"It was absolutely scary," Ms Murphy recalled.
"I had to actually put my home address in my phone in Google maps to get home."
Ms Murphy described herself as fit before she became infected with SARS-CoV-2, the virus that causes COVID, hiking the Carnarvon Gorge just a few months earlier.
"I didn't have chronic fatigue before I got long COVID, but I certainly have it now," she said.
"That's one of the main symptoms that I suffer with that I find very debilitating. In my job, we would work 12-hour shifts and I really worry about how I'm going to return to work.
"Quite frankly, I can't sometimes get through just doing normal housework without being fatigued."
In the absence of a public long COVID clinic in Queensland, Ms Murphy said Griffith University's research into low-dose naltrexone as a potential drug treatment for long COVID provided some optimism into the future.
The Gold Coast-based researchers are collaborating with Perth-based pain specialist and anaesthetist Dr James Jarman to trial naltrexone – a drug normally used in the treatment of alcohol addiction and opioid dependence – in long COVID patients.
"We really do need research to be looking at what we can actually do," Ms Murphy said.
"I think there are a lot of people out there that are suffering."
