CFS, OI in Gulf War vets
A study published in Psychosomatic Medicine compared 51 Gulf War (GW) veterans with chronic fatigue syndrome (CFS) symptoms and 42 veterans without CFS symptoms in three tests to measure symptoms of orthostatic intolerance (OI).

The first two tests found a difference in blood pressure reactions in two mental stress tests, indicating a suppressed cardiovascular response in GW vets with CFS symptoms.

A third test to detect different reflex responses to physical sensations showed both groups of vets performed equally.  The mental stress tests, which included math and speech tests, were expected to raise blood pressure, but the increase was much lower among the patients with CFS symptoms than the healthy vets.

The least noticeable blood pressure responses were found in those with the most severe CFS symptoms, suggesting a disconnect between cardiovascular stress responses and mental activities.

Herpesvirus role examined
The Centers for Disease Control and Prevention (CDC) was unable to find an association between the human herpesviruses (HHV) 6 and HHV-7 and CFS.  This study, published in the journal Clinical Infectious Diseases, is certain to provoke controversy in the CFIDS community.

The study involved 26 CFS patients and 52 non-fatigued matched controls. Researchers used several different viral detection methods, including serum samples, lymphocyte assays and polymerase chain reaction (PCR).

All 26 CFS patients and 52 control subjects tested positive for HHV-6 and the antibody titer was not significantly different between patients and controls. Neither HHV-6 nor HHV-7 was isolated from peripheral blood lymphocytes of patients or control subjects, a sign that no active infection or viral reactivation was involved.

HHV-6 (A or B) DNA was detected in 22.4% of samples and there were no significant differences between patients and control subjects. HHV-7 DNA was more common in controls (24%) than patients (7.7%) but the difference was not statistically significant.

The researchers concluded that there was no evidence of active or latent infection with HHV-6A, HHV-6B, HHV-7 or any combination of these viruses associated with CFS. Other studies showing an association between HHV-6 or HHV-7 infection and CFS have been published, but it is difficult to compare them because of the different methodologies used.

Konnie Knox, PhD, and Donald Carrigan, MD, of ViraCor Diagnostic Labs, who have reported an association between HHV-6 and CFS, say that the problem with the CDC testing is that it used methods that are inaccurate for detecting active HHV-6 infection.

CFS patients and surgery
CFS or fibromyalgia patients with orthostatic intolerance (OI) who must undergo surgery may wish to read a case study in the journal Anesthesiology.  [Please Note: Individuals who do not subscribe to the journal Anesthesiology will have to pay a small fee for a copy of the article, "Perioperative Considerations in a Patient with Orthostatic Intolerance Syndrome," which appears on page 571 of the August 2000 issue.]  The article describes the presurgery treatment of a patient with severe OI who underwent a bilateral mastectomy.

The patient was given a low-dose phehylephrine infusion with volume expansion since she was also receiving inhaled isoflurane or epidural ropivacane, drugs that can cause dilation of the arteries and veins. The phenylephrine and volume expansion helped augment her arterial pressure and vascular tone and reduced the chance for fluctuation in her autonomic nervous system during and after surgery.

The authors also noted that for patients with OI, neuroaxial opioids may be effective for intra-operative and postoperative pain.

Prevalence of comorbid conditions
Researchers from DePaul University have examined comorbidity rates for CFS, fibromyalgia (FM) and multiple chemical sensitivities (MCS) and characteristics related to fatigue severity and disability.

The study, published in Psychosomatic Medicine, involved 32 individuals with symptoms of CFS who received medical and psychiatric evaluations to confirm the diagnosis. Of the 32, 40.6% met criteria for MCS and 15.6% met criteria for FM. Thirteen of the 32 (40.6%) had CFS without any coexisting illness.

These rates for coexisting illnesses are lower than those reported in prior studies. The researchers speculated that the discrepancy may in part be attributed to differences in sampling procedures.

Researchers noted that having comorbid conditions does affect a patient’s functionality. Individuals with more than one diagnosis reported more mental and physical fatigue than those with no diagnosis and were less likely to be working.

Effect of exercise
A study conducted by St. Bartholomew’s and the Royal London School of Medicine found that the CFS patients were physically weaker than the sedentary and depressed controls and as unfit as the sedentary controls. They also showed lower aerobic capacity and lower maximum heart rate than the controls.

The study, published in the Journal of Neurology, Neuro-surgery and Psychiatry, measured the strength, aerobic capacity and functional capacity of 66 CFS patients who had not been diagnosed with a psychiatric disorder, 30 healthy but sedentary controls and 15 patients with major depressive disorders. Exercise capacity and efficiency were assessed by monitoring peak and submaximal oxygen uptake, heart rate, blood lactate, duration of exercise and perceived exertion during a treadmill test.