CHRONIC FATIGUE SYNDROME CFS DIAGNOSTIC AND ASSESSMENT ISSUES

CHRONIC FATIGUE SYNDROME (CFS) DIAGNOSTIC AND ASSESSMENT ISSUES

Case Definition [C. D. C. , 1994] A) Clinically evaluated, unexplained persistent or relapsing chronic fatigue ( 6 months duration) that is of new or definite onset (has not been lifelong); is not the result of ongoing exertion, is not substantially alleviated by rest; and results in substantial reduction in previous levels of occupational, educational, social, or personal activities.

Case Definition [C. D. C. , 1994] • B) Four or more of the following symptoms are concurrently present for > 6 months: • 1. Impaired memory or concentration • 2. Sore throat • 3. Tender cervical or axillary lymph nodes • 4. Muscle pain • 5. Multi-joint pain • 6. New headaches • 7. Unrefreshing sleep • 8. Post-exertion malaise

Diagnostic Hints • Diagnostic based on inclusion and exclusion criteria • No pathognomonic signs or diagnostic tests validated in scientific studies • Must have persistent or relapsing, debilitating fatigue for at least 6 mo. • In the absence of any current or past medical condition that would explain the clinical presentation

A discrete clinical entity? This question raises 2 issues: • Usefulness of the diagnosis • Overlap with other clinical conditions

A discrete clinical entity? • CFS, Fibromyalgia, Irritable Bowel Syndrome or Idiopathic chronic Pain as associated disorders (Goldenberg, 1999) • a diagnostic label promoting illness behavior and exaggeration of the expression of disability and pain (Barsky and Borus, 1999)

A discrete clinical entity? • However a useful diagnosis: – reassures patients on the absence of a degenerative disease – allow patients to concentrate on getting better rather than getting a diagnosis and searching for a cause or a cure (Goldenberg, 1999)

A discrete clinical entity? • 90% of patients believed that a diagnosis of CFS was the most helpful factor in managing their symptoms (Hewett et al. , 1995) • CFS, FM, and TMD shared many clinical features (e. g. , myalgia, fatigue, sleep disturbances, impairment in daily activities) (Aaron et al. , 2000)

A discrete clinical entity? • Frequent co-morbidity among CFS, FM, and TMD patients (e. g. , 35 to 70% patients with CFS also had FM) • A stress-related illness, with onset related to acute or chronic emotional stressors, or to a combination of emotional and physical events (Demitrack & Crofford, 1998)

Differential Diagnosis Considerable phenomenological overlap with other functional somatic syndromes Therefore a discussion of a common set of psychosocial factors applies to all of them (Barsky and Borus, 1999)

Differential Diagnosis CFS and Depression • CFS might be a variant of a neuropsychiatric disorder, such as major depression (Brickman and Fins, 1993) • Frequent comorbidity observed in the population of CFS patients (Goodnick, 1993) • Issue of directionality (cause or effect)

Differential Diagnosis CFS and Depression • Shared symptoms: - persistent fatigue - pain - sleep disturbance - poor concentration - psychomotor retardation - loss of sexual desire (Friedberg & Jason, 2001)

Differential Diagnosis CFS and Depression • CFS more debilitating than depression • More severe neurocognitive symptoms in CFS (e. g. , memory and concentration, mental confusion) • Symptoms less likely to be reported in primary depression (e. g. , painful lymph nodes, flu-like symptoms, pressure-like headaches, alcohol intolerance)

Differential Diagnosis CFS and Depression • Key distinction: Postexertional malaise and prolonged fatigue after exercise - atypical in primary depression (often mood elevation with exercise) (Moor & Blumenthal, 1998)

Differential Diagnosis CFS and Depression • Loss of interest (Depression) vs. Loss of ability (CFS) Ask for 5 things they want to do • Cognitive differences: - CFS: more likely to endorse tendencies to dwell on fatigue - Depression: thoughts of worthlessness, self-criticism, suicidal ideation more common

Differential Diagnosis CFS and Somatization Disorder (SD) • Differences in onset: - CFS: often sudden onset, late 20’s/early 30’s - SD: progressive, starting in adolescence, full-blown somatization by 25 • Medically unexplained symptoms in both hard to delineate

Differential Diagnosis CFS and Anxiety • CFS often accompanied by persistent anxiety • Focus on prominent feature to distinguish GAD from CFS: - CFS: severe fatigue - GAD: excessive persistent anxiety, not necessary w/pain or profound fatigue (treated w/CBT)

Differential Diagnosis CFS and Activity-Induced Chronic Fatigue • 2 types of CFS patients: - severe post exertional fatigue, slightly alleviated by rest - severe overall symptomatology, severe postexertional fatigue, fatigue not alleviated by rest • Healthy people: persistent fatigue due to active schedules, high stress, lack of sleep – remission of symptoms with increase in rest and leisure time

Hypotheses to account for CFS • Functional somatic syndrome Barsky and Borus (1999); Sharpe and Wessely (1997) • Abnormalitites in immune functions Klimas et al. (1990, 1994); Patarca et al. (1993) • Viral etiology of CFS Jones et al. (1985); Straus et al. (1985) • Perturbations of the HPA axis function Demitrack et al. (1991) • Brain stem hypometabolism Buskila (2000)

Physiological abnormalities in CFS • researchers have extensively tested for: - immune status - infectious agents - disorders of the endocrine or central nervous systems • No need for such testing in practice unless as part of a protocol-based research study or when the diagnosis is in question

Explanatory Models of CFS • Immune defect Model • Sleep disturbance Model • Neuroendocrine Abnormalities • “Predisposing Personality” Model • Symptom Avoidance Model

The Mind & Body Approach • Assessed and Treated in a nonspecific manner • But integrated medicalpsychiatric approach the clinical assessment and care of functional somatic syndromes • Intervention model based on 4 axes

A Multidimensional Model • Distinguishes: - Predisposing factors - precipitating factors - perpetuating factors (Demitrack & Crofford, 1998)

A Conceptual Framework and set of Guidelines • Need for a comprehensive, systematic, and integrated approach to the evaluation, classification, and study of people with CFS or other fatiguing illnesses (Fukuda et al. , 1995)

A Conceptual Framework and set of Guidelines • Need for revised criteria to define CFS • Need for clinical evaluation standards • Definition and Clinical evaluation of Prolonged and Chronic fatigue

A Conceptual Framework and set of Guidelines • Prolonged Fatigue Self-reported, persistent fatigue of 1 month or longer • Chronic Fatigue • Self-reported, persistent or relapsing fatigue of 6 or more consecutive months

A Conceptual Framework and set of Guidelines • Clinical Evaluation To identify underlying or contributing conditions that require treatment For further diagnosis or classification of chronic fatigue cases

A Conceptual Framework and set of Guidelines Areas to include in evaluation: • History of medical and psychosocial circumstances at onset • Mental status Exsamination • Physical Examination • Minimum battery of lab screening tests

Conclusion • Specific and non-specific assessment: standard tools and customized clinical interview • Biopsychosocial Approach • Mastery of Case Definition Criteria • Diagnostic reevaluation based on initial treatment response

Conclusion • Challenging diagnosis and treatment that will benefit from continuous research and education of primary health care providers • Importance of experience with this specific population – requires special training (CEU)