PET to diagnose chronic fatigue

Functional positron emission tomography (PET) has revealed that patients with chronic fatigue syndrome have higher levels of neuroinflammation or inflammation of the nervous system. Neuroinflammation has been hypothesised to be the cause of the condition – also known as myalgic encephalomyelitis – but there has previously been no clear evidence to confirm this. This new research, published in The Journal of Nuclear Medicine, shows that the levels of neuroinflammation markers are elevated in CFS/ME patients. Researchers at the RIKEN Center for Life Science Technologies, Osaka City University and Kansai University of Welfare Sciences performed scans on nine people who had been diagnosed with CFS/ME, and 10 healthy controls. The subjects were also asked to complete a questionnaire describing their level of fatigue as well as cognitive impairment, pain and depression, which are all characteristic of the disease. They used a protein expressed by microglia and astrocytes cells which are known to be active in neuroinflammation and found that inflammation in certain areas of the brain – the cingulate cortex, hippocampus, amygdala, thalamus, midbrain and pons – was elevated in a way that correlated with symptoms. For example, patients reporting impaired cognition tended to demonstrate neuroinflammation in the amygdala, known to be involved in cognition. The researchers say this provides clear evidence of a link between neuroinflammation and the symptoms of CFS/ME. Although the study was only small, it provides confirmation that PET scanning could be used as an objective test for CMS/ME and could lead to better diagnosis and the development of new therapies. “We plan to continue research following this exciting discovery in order to develop objective tests for CFS/ME and ultimately ways to cure and prevent this debilitating disease,” said Dr Yasuyoshi Watanabe, who led the study at RIKEN. Neuroinflammation in Patients with Chronic Fatigue Syndrome/Myalgic Encephalomyelitis: An 11C-(R)-PK11195 PET Study