Diabetic Neuropathy: A Focus on the Testing Method

Diabetic neuropathy is the most common chronic complication of diabetes. Among the three major complications of diabetes, diabetic neuropathy is frequent and appears earliest after the onset of diabetes. Diabetic neuropathy presents various clinical symptoms from head to toe (and sole). Identification of the early signs of neuropathy in diabetic patients, early diagnosis, and appropriate management in the early stages are very important for the following reasons. First, the early diagnosis of diabetic neuropathy is difficult. Because multiple tests are required for diagnosis, the examination methods are often complicated and time consuming. It is also necessary to rule out differential diagnoses. Non-diabetic neuropathy may occur in patients with diabetes and requires specific treatment. Second, treatments for symptomatic diabetic neuropathy are available. Third, diabetic neuropathy can be asymptomatic in up to 50% of cases. If it is not recognized and preventive foot care has not been implemented, the patient is at risk of injuring the foot. Asymptomatic diabetic neuropathy is a sign of serious complications. In this review, we describe the classification, symptoms, diagnosis, examination, mechanism, prevention, and treatment of diabetic neuropathy. This review details a method for examining distal symmetric polyneuropathy (DSPN), which is the most frequent type of diabetic neuropathy. Additionally, we discuss a new tactile test method that the authors are investigating for the early detection and diagnosis of diabetic neuropathy, which is currently difficult in routine diabetes practice.