Imaging shows brain abnormalities in chronic fatigue syndrome patients

In a study that could help shed light on the complexities of chronic fatigue syndrome (CFS), the brains of patients with severe CFS were found to have structural abnormalities when analyzed with a combination of different imaging techniques.

Specifically, the patients had increased fractional anisotropy in the anterior right arcuate fasciculus when compared with control subjects, according to findings published online Oct. 29 in Radiology.

CFS is a disorder that affects more than one million Americans and is characterized by extreme tiredness and a symptom known as “brain fog” not directly caused by another medical condition.

Headed by Michael M. Zeineh, MD, of the Stanford University Medical Center, the research team sought to identify differences in brain structures in patients with CFS by using volumetric analyses in addition to detecting microstructural abnormalities and global alterations in brain perfusion of chronic fatigue syndrome patients.

The study began in 2011 with follow up completed in November 2013. It focused on 15 patients who met study criteria including fatigue for six months or longer, along with having at least four of eight Fukuda symptoms (impaired memory or concentration, sore throat, tender lymph nodes, headaches, muscle pain, joint pain, unrefreshing sleep, and postexertional malaise).

Patients were partnered with age- and sex-matched control participants who also underwent MR imaging.

Results showed the CFS patients had slightly less white matter volume, or less overall white matter in the brain. They also had abnormally high fractional anisotropy values—a measure of the dispersal of water—in a specific white matter tract called the right arcuate fasciculus, suggesting something was happening in the white matter of the right hemisphere in CFS patients.

“Within CFS patients, right anterior arcuate FA increased with disease severity,” Zeineh said in a press release. “The differences correlated with their fatigue—the more abnormal the tract, the worse the fatigue.”

Zeineh and team also found anomalies in CFS patients at the cortexes, two points in the brain that connect the right arcuate fasciculus. These connection points were thicker in CFS patients.

Fractional anisotropy at the right arcuate fasciculus may serve as a biomarker for CFS, the study suggested, and can help healthcare professionals track the disease.

“This is the first study to look at white matter tracts in CFS and correlate them with cortical findings,” Zeineh said. “It’s not something you could see with conventional imaging.”