Findings of brain anomalies may shed light on chronic fatigue (Caused by HHV-6???)

 Radiology researchers have discovered that the brains of patients with chronic fatigue syndrome have diminished white matter and white matter abnormalities in the right hemisphere.

Three key findings

The analysis yielded three noteworthy results, the researchers said. First, an MRI showed that overall white-matter content of CFS patients’ brains, compared with that of healthy subjects’ brains, was reduced. The term “white matter” largely denotes the long, cablelike nerve tracts carrying signals among broadly dispersed concentrations of “gray matter.” The latter areas specialize in processing information, and the former in conveying the information from one part of the brain to another.
That finding wasn’t entirely unexpected, Zeineh said. CFS is thought to involve chronic inflammation, quite possibly as a protracted immunological response to an as-yet unspecified viral infection. Inflammation, meanwhile, is known to take a particular toll on white matter.

But a second finding was entirely unexpected. Using an advanced imaging technique — diffusion-tensor imaging, which is especially suited to assessing the integrity of white matter — Zeineh and his colleagues identified a consistent abnormality in a particular part of a nerve tract in the right hemisphere of CFS patients’ brains. This tract, which connects two parts of the brain called the frontal lobe and temporal lobe, is called the right arcuate fasciculus, and in CFS patients it assumed an abnormal appearance.

Furthermore, there was a fairly strong correlation between the degree of abnormality in a CFS patient’s right arcuate fasciculus and the severity of the patient’s condition, as assessed by performance on a standard psychometric test used to evaluate fatigue.

 http://med.stanford.edu/news/all-news/2014/10/study-finds-brain-abnormalities-in-chronic-fatigue-patients.html


 "The first, using magnetic resonance imaging that looked at overall size of certain types of brain matter, found that so-called white matter areas were smaller in the brains of chronic fatigue patients than in healthy subjects."


"Unexpected, however, was the discovery of abnormalities in a tract of the brain called the arcuate fasciculus, which connects the frontal and temporal lobes. Zeineh’s team uncovered these abnormalities using a scanning technique that looks at water displacement in the brain.
In the brain’s left hemisphere, the arcuate fasciculus connects areas devoted to language production and comprehension. But the chronic fatigue study found abnormalities only in the right hemisphere, and scientists aren’t sure what that part of the brain does on the right side. The team also found that in areas of the brain that were connected by the arcuate fasciculus, the gray matter was thicker.
Both findings involving the arcuate fasciculus suggest that the tract may be hyperactive in chronic fatigue patients, Zeineh said. But he noted that he’s only able make guesses for now."

http://www.sfgate.com/health/article/Findings-of-brain-anomalies-may-shed-light-on-5851844.php

Right Arcuate Fasciculus Abnormality in Chronic Fatigue Syndrome

Conclusion

"Bilateral white matter atrophy is present in CFS. No differences in perfusion were noted. Right hemispheric increased FA may reflect degeneration of crossing fibers or strengthening of short-range fibers. Right anterior arcuate FA may serve as a biomarker for CFS."
 http://pubs.rsna.org/doi/abs/10.1148/radiol.14141079?journalCode=radiology&

 

HHV-6 in Multiple Sclerosis

"Multiple sclerosis (MS) is a chronic, inflammatory, demyelinating disease of the white matter in the human central nervous system (CNS). The origin of MS is still unclear despite the many epidemiological, immunological, and neurological studies that have been conducted. Viruses have long been proposed to be either initiating factors for, or directly pathogenic in, the development of MS. These viruses may play a role both at the onset of the disease and during it and may trigger the exacerbations that are commonly seen with relapsing-remitting multiple sclerosis (RRMS). Although an etiological correlation has not been definitively proven, during the past few years many studies have focused on the relationship between human herpesvirus 6 (HHV-6) and MS. The virus is widely prevalent in the human population, and primary infection usually takes place in the first years of life. However, HHV-6 reactivates under certain conditions, and has been associated with RRMS and, specifically, with exacerbations. MS exacerbations (also known as a relapse, attack, or flare-up) cause new symptoms or the worsening of old symptoms. Relapses can be very mild or severe enough to interfere with a person’s ability to function on a day-to-day basis."
 http://www.coppelabs.com/about-hhv-6/hhv-6-in-ms