The objective of the work was to evaluate the contribution of examining autonomic neuropathy in diabetic patients to early diagnosis of Charcot´s osteoarthropathy by classical Ewing´s tests, as well as the more recent method - spectral analysis of heart rate variability. The authors examined 18 diabetic patients in the early stage of Charcot´s osteoarthropathy and the results were compa- red with a group of 30 subjects matched for age and sex. The results of examination by Ewing´s test ( heart rate variability during deep breathing, in orthostasis and during Valsalva´s manoeuv- re and blood pressure changes during orthostasis) revealed autonomic neuropathy in all exami- ned patients, in one subject incipient neuropathy and in 17 of 18 patients manifest or severe neuropathy. The patients differed from controls highly significantly in all parameters of Ewing´s tests with the exception of parameter 30:15 in orthostasis. The greatest sensitivity was recorded in the examination of the I-E difference during deep respiration. RRmax/RRmin and the brake in- dex in orthostasis and Valsalva´s ratio. The lowest sensitivity was recorded in the examination of the orthostatic fall of blood pressure. On spectral analysis the patients differed highly significan- tly from controls in all investigated parameters, the highest discriminating value was found in pa- rameters of the total spectral power in the standing position (2) and the power in the low-frequency area in position 2, the first parameter alone was correctly discriminated in 94%.Summary: Examination of autonomic neuropathy significantly improves the diagnosis of Charcot´s osteoarthropathy. In addition to the classical Ewing tests spectral analysis of heart rate variability proved also a suitable method for its evaluation.

        Key words: Diabetes - Autonomic neuropathy - Spectral analysis - Diabetic foot - Charcot´s osteo- arthropathy.