People who suffer from Chronic Fatigue Syndrome often have a real odyssey behind them. Because a diagnosis is difficult because of the difficult to understand symptoms, clear biomarkers are missing. Some patients have to listen to it, they are hypochondriacs. But now, US researchers in the brain of sufferers have discovered for the first time clear characteristics for this disease. This could facilitate the diagnosis and even provide evidence of the cause of the still puzzling condition.
In Germany, about 300,000 people suffer from Chronic Fatigue Syndrome (CFS), and the number of affected persons worldwide is estimated to be more than 15 million. CFS sufferers typically suffer persistently and without apparent cause of physical and mental exhaustion. Frequently, muscle pain, digestive problems, memory and sleep disturbances or even blood pressure changes are added. Because not everyone affected has the same symptom scale and so far lacked distinctive physical markers for the disease, a clear diagnosis is difficult. The causes of the disease are still unknown. “CFS is one of the greatest scientific and medical challenges of our time,” says senior author Jose Montoya from Stanford University.
In search of a clear physical indicator of the disease, the researchers turned to the brain. “We were wondering if specific brain scans might reveal anything that is different in CFS patients than in healthy people,” says first author Michael Zeineh from Stanford University. For their study, therefore, they formed the brain structures of 15 affected persons using three different methods. One is the so-called diffusion-tensor imaging. This method is based on magnetic resonance tomography, but can more accurately describe the course of nerve fibers in the brain and thus the structures of the so-called white matter. These images were then compared with brain scans by the same healthy volunteers.
Three striking changes in the brain
And indeed, the researchers even encountered three striking differences, as they report. On the one hand, the white matter in CFS patients was significantly reduced in comparison to that of the healthy persons. Possibly, the scientists suggest, unspecific inflammatory processes are caused by the disease. The fact that such inflammation affects white matter has long been known.
Secondly, the researchers discovered an abnormal change in the right hemisphere of the CFS patients: a nerve strand connecting the frontal lobes with the lobe of the femur looked deformed, as the researchers report. The degree of abnormality seemed to be related to the severity of symptoms, for the more severe the chronic exhaustion in a patient, the stronger was the so-called Fasciculus arcuate. The function of this nerve strand in the right hemisphere of the brain, however, has been largely unknown. For up to now, only his counterpart in the left hemisphere has been investigated, as the researchers explain. This is known as linking the two language centers Wernicke-Areal and Broca-Zentrum, and that damage to this line leads to speech disturbances. The third finding was a thickening of the gray matter in the parts of the frontal and lobe lids, which were connected by the fasciculus arcuate.
“We have thus determined that the brain of a CFS patient differs from that of a healthy person in at least three characteristics,” says Zeineh. “This could finally provide the diagnostic marker we’ve been looking for in despair for decades.” At the same time, however, the new findings also provide approaches for a search for the causes of the mysterious disease. The researchers now want to review their findings in a forthcoming major study.