[Significance of the chronic fatigue syndrome in rehabilitation medicine--status and perspectives].

It appears that from a clinical point of view chronic exhaustion or fatigue is an important factor in rehabilitation. This is, however, first of all a phenomenon that can be described as a function in accordance with the International Classification of Functioning, Disability and Health (JCF), caused by chronic illnesses or chronic excessive stress. The clinical and sociomedical ranking of chronic fatigue or exhaustion in respect of rehabilitation was discussed in the framework of a Workshop at the 12th Rehabilitation Science Colloquium, 2003 from the viewpoints of psychiatric rehabilitation, methodology, sociology and practical rehabilitation, and conclusions for future research were drawn. The definition of chronic fatigue is first of all mainly based on the feeling of chronic tiredness but also on phenomena of disturbed concentration, physical discomfort, headache and disorders of "drive" and mood. A psychiatric diagnosis linked with symptoms of chronic fatigue is neurasthenia, which is arrived at according to precisely defined criteria. Depressive disorder is one of the most important differential diagnoses in this sphere. Examinations by general practitioners revealed that about 90 % of the patients who had been diagnosed as suffering from psychovegetative disorders completely agreed with the diagnosis of neurasthenia. Neurasthenia resulted more often in work disability periods than disorders of somatisation and other psychosomatic diagnoses. Basing on the "IRES" scale "vital exhaustion", singular of even serious changes become evident in about 50 % to 90 % of the patients undergoing rehabilitation, depending on their individual range of indications. As was to be expected, the majority of pathologic findings concerns patients undergoing psychosomatic rehabilitation, since in such cases there is an overlapping with symptoms of psychosomatic diseases. It is, however, remarkable that also in somatically oriented orthopaedic rehabilitation symptoms of fatigue are seen in up to 50 % of the patients. Preliminary studies have shown that these symptoms can be definitely ameliorated within the rehabilitation framework, although pathological signs are still abundantly apparent in follow-up examinations. Markedly severe degrees of "vital exhaustion" and "vocational exhaustion" are also seen in rheumatology patients undergoing somatic rehabilitation. This agrees with case history details related by many female and male patients. Hence, it appears necessary to adapt rehabilitative intervention to both the psychovegetative and the medical behavioural aspects of this symptom. Scientific classification of the entire sphere of chronic fatigue in respect of rehabilitation requires classification of the relevant functions within the ICF framework. To this end it would be necessary to conduct patient inquiries within cross-sectional studies on the one hand and, on the other, a systematic consensus process among experts would have to be used for allocation to the relevant functions. This is the basis for development of suitable assessment tools for use in prospective studies in order to systematically evaluate the impact on functions and especially their effects on activities and participation.