New study: Awareness of Clinical Distinctions May Lead to Improved Diagnosis

(http://cfidsreport.com) 5/05 - Researchers at Depaul University have published a study with the goal of eventually improving the diagnosis of Chronic Fatigue Syndrome. The study compared three groups of patients: CFS, major depressive disorder, and healthy controls. The researchers examined common methods that may be used to improve CFS diagnosis: observation of unique symptoms, use of severity ratings, and implementation of standardized measurements. The study concluded that the use of all three methods can improve diagnosis and research of CFS.

The Centers for Disease Control case definition for CFS has been widely criticized. The CDC has broadened the definition of CFS, urging researchers to integrate fatiguing illnesses into the CFS rubric and downplay clinical distinctions. Concerns have since been raised that the current definition is placing patients with purely psychological and psychiatric issues within the CFS criteria. The authors, Leonard Jason and Carol King from DePaul University, state “it is very possible for a person with either MS or major depression to fulfill the symptomatic criteria of the current CFS case definition…” Resolving this problem has been a long held goal of researchers.

Awareness of distinct symptoms was found to be the best way to differentiate CFS from depression and healthy controls. One symptom was found to diagnose CFS patients most effectively, post exertional malaise. CFS patients have been known to exhibit a strong post-exertional response with 24-48 hours of activity. “When looking specifically at the occurrence of fatigue and the eight symptoms of the current U.S. case definition, only one symptom, post-exertional malaise, was found to occur significantly more frequently in the CFS group….

Meanwhile, the authors state that, “fatigue, unrefreshing sleep, impaired memory & concentration, and muscle pain all occurred significantly more in the MDD [depression] group… Taken together, these findings strongly suggest that when using symptom occurrence alone, there is a strong potential for individuals with MDD [depression] to be misclassified as having CFS.” The CFS case definition is based on symptom occurrence.

Severity measures were also useful in differentiating between CFS, depression, and healthy controls. CFS patients experienced more symptom severity in most symptom areas, such as the ‘infectious’ and ‘cardiocirculatory’ categories. The authors theorize that attention to severity can be a useful tool in diagnosing CFS.

The study confirms what many researchers have been saying for some time: diagnostic procedures for CFS will improve with awareness of the distinct symptoms of CFS. Post-exertional malaise, orthostatic intolerance, and flu-like symptoms are each a large part of what differentiates patients with CFS. Attention to severity and standardized measures may also improve both diagnosis and research outcomes.