Evaluation of the Indicator Test(NeurocheckTM) in the Diagnosis of Peripheral Neuropathy among Type 2 Diabetic Patients

Sohn, Tae Seo; Son, Hyun Shik; Yu, Jae Myung; Cha, Bong Soo; Min, Kyung Wan; Baik, Sei Hyun

Abstract

BACKGROUND: Eighty-five percent of the lower-limb amputations that are done for patients with diabetes are preceded by foot ulceration, and this suggests that prevention and the appropriate management of foot lesions are of paramount importance. Ulceration is caused by several factors acting together, but they are particularly caused by neuropathy. Various aspects of the neurovascular function can be evaluated with specialized tests, but these tests have generally not been well standardized and they have limited clinical utility. A new indicator test(NeurocheckTM) that utilizes the water-induced color change of a cobaltII compound from blue to pink has been introduced. The aim of the present study was to evaluate this new indicator test in the diagnosis of peripheral neuropathy among type 2 diabetic patients. METHOD: This study included 124 diabetic patients(45 men and 79 women) who were recruited from 5 diabetic centers in Korea. The presence of diabetic neuropathy was diagnosed by nerve conduction study. The degree of the patient's symptom was checked as the total symptom score(TSS). Autonomic sudomotor neuropathy was assessed by means of the new indicator test(NeurocheckTM). The degree of color change in 10 minutes was assessed as a complete color change, an incomplete color change or no color change.
RESULTS
Of the 124 diabetics patients we investigated, 109 patients were proven to have peripheral neuropathy by nerve conduction study. Autonomic sudomotor neuropathy by NeurocheckTM was diagnosed in 94 patients with peripheral neuropathy(86.2%) and in 6 patients(40%) without peripheral neuropathy. The overall measure of agreement between NeurocheckTM and the electrodiagnostic test was 0.3673(0.1547, 0.58). The sensitivity and specificity of NeurocheckTM was higher in women(91.2% and 63.6%, respectively) than in men(78.0% and 50.0%, respectively). The measure of agreement in women was 0.5093(0.2396, 0.9601) and in the men it was 0.1567(-0.1423, 0.4588).
CONCLUSION
The new indicator test has a high sensitivity for the diagnosis of peripheral neuropathy among diabetic patients, especially in women. It is likely that the new indicator test is useful clinically as a screening and diagnostic tool for diabetic neuropathy. Since the specificity of the test is somewhat low, the patients with a high total symptom score and who are without sudomotor neuropathy may need further diagnostic evaluation on neuropathy