Scientists Find Markers of Chronic Fatigue Syndrome

Profound, constant exhaustion is one likely indicator of chronic fatigue syndrome (CFS), but scientists might soon be able to diagnose the disorder without any doubt using brain-imaging technology.

Researchers from the Stanford University School of Medicine have identified structural abnormalities in the brains of people with CFS using MRI scans. A longstanding but unreliable checklist of symptoms has been the gold standard for diagnosing the disease.

“This is more conclusive evidence of something being biological in the brains of people with CFS,” said lead study author Dr. Michael M. Zeineh, Ph.D., an assistant professor of radiology at the Stanford University School of Medicine.

The new research was published in the journal Radiology.

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A New Way to Detect CFS

CFS is often confused with another illness, or simply dismissed as being “all in the patient’s head.” As a neuroradiologist, Zeineh can identify certain conditions, such as brain tumors or stroke, with relative ease, but CFS is one condition whose symptoms aren’t always clear-cut.

“By doing a more detailed scientific analysis, we wanted to see if we could uncover some underlying symptoms,” Zeineh said.

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Zeineh and Dr. Jose G. Montoya, a CFS and infectious disease expert at Stanford, looked beyond the anecdotal evidence of CFS in their study. They performed three different MRI scans on 15 patients with CFS and on 14 healthy volunteers.

By using volumetric analysis to measure different areas of the brain, diffusion tensor imaging to assess the condition of the brain’s white matter, and arterial spin labeling to measure blood flow, the scientists found several crucial differences in the brains of the CFS and control participants.

People with CFS had a slightly lower volume of white matter, which connects regions of gray matter in the brain. These patients also had very high fractional anisotropy (FA) values, a measurement of water diffusion, in a specific white matter tract called the right arcuate fasciculus.

Another abnormality appeared in the cortices, two points in the brain that connect to the right arcuate fasciculus. Each cortex was thicker in CFS patients than in the brains of the control participants.

What This Study Means for CFS Patients 

The location of the irregularities suggests a complication in the white matter of the right hemisphere of the brain, but what exactly is going on in this area has yet to be confirmed.

Zeineh has several hypotheses about the cause of CFS based on similar observations in other diseases. Brain inflammation could be grounds for CFS because it is often linked to white matter, as is the case in multiple sclerosis. Brain hyperactivity could also be to blame. 

While some parallels with other diseases, such as MS and fibromyalgia, are intriguing to scientists, Zeineh is cautious about making any assumptions.

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The roots of chronic fatigue syndrome have long been mysterious for patients and physicians, but the discovery of a specific biomarker for the condition is a major step forward.

The study is small in size and does not yet provide doctors with recommendations for treatments, but Zeineh finds this progress exciting nonetheless. A larger study that will track patients over a longer period of time is already in the works.

“As a neuroradiologist I know that imaging is important to patients, and by doing research to advance imaging ... we can push the technology further than it’s been pushed before,” he said.