The study, published in the March 2001 issue of The International Journal of Neuroscience, looked at 48 people with CFS (PWCs) who had recently undergone brain MRIs. The subjects filled out questionnaires asking them to rate their own health status.

The MRIs showed that 25 of the 48 subjects had brain abnormalities that have been associated with CFS in previous research. Most of those 25 people rated themselves as more physically impaired than did those with normal MRI scans.

The researchers say their work should help disprove the notion that CFS is primarily a psychological illness. They also write that the findings may someday help doctors classify PWCs into sub-categories based on physical changes that accompany the disease. Further studies could determine whether the link between brain abnormalities and CFS symptoms is truly significant.

The study was conducted by researchers at the University of Medicine and Dentistry of New Jersey Medical School in Newark, N.J.

Brain changes and pain in CFS
Preliminary findings from an ongoing study at the University of Alabama at Birmingham show that CFS patients react differently to pain than either healthy controls or fibromyalgia (FM) patients.

Researchers found no difference in the way that CFS patients and healthy people perceive and rate pain. However, during a resting state without painful sensations, CFS patients have significantly higher levels of blood flow through certain parts of the brain associated with pain perception and response.

Fibromyalgia patients typically experience greater pain sensitivity than healthy people, yet show lower resting-state levels of blood flow in areas of the brain that process pain.

CFS patients’ brains also mount a slightly different brain response to painful sensations. When brief painful pressure is applied to the right side of the body in healthy individuals, blood flow to regions in the left side of the brain increases. In CFS patients, blood flow increases to both sides of the brain.

"We may be able to use this information to identify factors that increase the abnormal brain response in CFS and to develop treatments to address that symptom," said Dr. Laurence Bradley, lead investigator on the study.

Data from the study was presented at the 20th Annual Scientific Meeting of the American Pain Society on April 20, 2001.

Lower cortisol levels discovered again
Researchers at King’s College Hospital in London say they have found more evidence that people with chronic fatigue syndrome may have low levels of the hormone cortisol. The report was published in the April 2001 edition of the American Journal of Psychiatry.

The researchers compared urine samples taken from 121 PWCs with those from a group of 64 healthy control subjects. In general, PWCs showed "mild," but statistically significant, reductions in urinary free cortisol.

Cortisol is produced by the adrenal glands, located near the kidneys. The hormone is released in large quantities during times of stress. Cortisol helps the body energize itself by increasing blood pressure and raising blood-sugar levels to provide fuel for the brain and muscles.

The study does not address whether cortisol levels may be a cause of CFS or merely a by-product of the disease. Many doctors believe that CFS has multiple causes - one of which may be reduced production or improper use of cortisol.

CFS, FM differ in tilt test
People with CFS and FM respond differently to tests that measure the heart’s reaction to stress while seated, standing and lying down, according to a study in The Journal of Rheumatology.

Israeli researchers conducted tilt tests for 30 people with CFS, 38 with FM and 37 healthy controls. The tests compare blood pressure and heart rate changes in patients who are strapped to a table that places them upright and flat on their backs.

Test results showed that people with FM responded in similar ways to the healthy controls, while the CFS group showed markedly different results. The researchers say this challenges the idea that people with FM and CFS share common changes in their stress-response systems.

The study appears in the Journal’s June 2001 issue.

Toxins may alter immune function
A small Italian study has found immune-system changes in people who developed symptoms of CFS after exposure to toxins.

Researchers tested five people who developed clinical features of CFS following ciguatera poisoning (from eating contaminated warm-water fish) or contact with poisonous chemical solvents. Blood samples showed that they had abnormal ratios of certain white blood cells when compared to other people with CFS.

Specifically, the ratio of "helper" cells (known as CD4 cells) to "suppressor" cells (CD8 cells) was higher than the ratio in people who developed CFS without toxic exposure. A high CD4/CD8 ratio can sometimes indicate that a person’s immune system is "switched on" to fight a foreign invader in the body.

Three of the five people studied also had a lower-than-normal number of natural killer cells, which attack harmful agents that enter the body. The researchers say they cannot explain why any of the cell counts were different, but they hope the findings can help them better understand the role that pathogens like toxic chemicals may play in CFS.

The study was published in the April 10, 2001 edition of The Science of the Total Environment. The researchers were from the CFS Research Center at the Department of Infectious Diseases at "G. d’Annunzio" University in Chieti, Italy.

HLA, CFS not linked?
New research appears to show no connection between human leukocyte antigens (HLA) and the development of CFS.

HLA are proteins on cell membranes that help identify whether other cells (such as those in viruses or transplanted tissue) are foreign to the body. The presence of certain HLA subtypes has been linked to other diseases, notably ankylosing spondylitis. A person’s HLA makeup is determined genetically.

Earlier studies found a possible correlation between some HLA subtypes and CFS. In one, CFS patients were more likely to have the subtype HLA DR4 than the general population.

But the new study looked at 58 people with CFS and 134 healthy controls and found no such connection. The researchers say advanced testing techniques allowed them to take a more accurate reading of HLA subtypes.

The study was published in the European Journal of Immunogenetics, Volume 28, No. 3. Keep in mind that research studies with fewer than 500 patients are generally not considered statistically valid and may be questioned by the medical community. The Chronicle reports on smaller studies due to the lack of large-scale research projects and to keep you updated on emerging trends.