[The Ewing test for autonomic neuropathy and spectral analysis of heartrate variability aid in the diagnosis of Charcot's osteoarthropathy].

UNLABELLED

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 compared 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 manoeuvre and blood pressure changes during orthostasis) revealed autonomic neuropathy in all examined 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 index 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 significantly from controls in all investigated parameters, the highest discriminating value was found in parameters 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.