An estimated 1 million Americans suffer from chronic fatigue syndrome, a cluster of symptoms that includes lethargy and weakness, especially after exertion.

Patients also suffer from cognitive impairment, restless sleep, and muscle aches. Some cases can lead to lost time at work and disrupted relationships.

The exact cause of the condition is unclear, but scientists have been exploring several contributing factors, including stress, immune system dysfunction, toxins, and central nervous system abnormalities.

Scientists from Stanford University published a study in the journal “Radiology” that compared 15 patients with chronic fatigue syndrome to 14 healthy subjects.

The fatigue patients showed abnormalities in the brain’s white matter, which connects nerve cells.

Patients with more severe symptoms showed greater white matter abnormality, which was not observed in control subjects.

In a second study from Osaka City University — published in the Journal of Nuclear Medicine — PET scans revealed increased inflammation in the brains of nine patients with chronic fatigue syndrome (compared to 10 healthy volunteers).

These new studies may lead to greater understanding of the brain alterations observed in chronic fatigue syndrome, which could lead to more effective diagnosis and treatment options.