Evaluation of cutaneous sensibility threshold on the feet of diabetic patients with the specified sensory device

Neuropathy is a severe progressive loss of protective sensation on the feet, making the patient more vulnerable to mechanical trauma and consequently more suitable to the development of chronic wounds and eventually to limb amputation. Prophylaxis should be enforced to avoid foot ulceration and for that, evaluation of the degree of loss of sensation on the skin is essential. Pressure of one or two points is tested both statically and with movement, thus assessing the function of fast and slow response nerve fibers, with specified sensory device. Threshold of two-point discrimination was also measured in mm. Three hundred and forty (n = 340) diabetic patients, type II, with no previous history of wounds on the lower extremity were studied using the tests, one point static (1PE), one point moving (1PD) and two points static (2 PE), and moving (2 PD) on the cutaneous territory of the fibular nerve and posterior tibial nerve (two territories – medial plantar and calcaneous nerves). The control group (280 non diabetic patients) was assessed by the same exams and the results were compared. In the diabetic group the cutaneous territories were also evaluated using the conventional Semmes-Weinstein filament nº 5,07 e vibrometer of the 128 Hz. Altered values were observed for the static and dynamic tests over the three studied nerve territories. The differences were statically significant (p < 0,05). Comparing the threshold of sensibility between sensitive and non sensitive diabetic patients to MSW nº 5,07 test, we observed that p-value range was 0,018 < p > 0,113 when 1PE test was applied, according to the cutaneous territories evaluated. Numeric quantification of the threshold of pressure allows us to determine the status of the fiber/receptor structures as well as the functional deficit of nerve fibers and the degree of loss of sensation on the skin.