Background: Early detection of neuropathy may prevent further progression of this complication in the diabetic patients. The purpose of this study was to evaluate the prevalence of early neuropathic complication in patients with newly diagnosed type 1 and type 2 diabetes. Methods: Nerve conduction studies (median, ulnar, posterior tibial, peroneal, and sural nerves) were performed for 49 type 1 (27 males, mean 14.1±7.5 years) and 40 type 2 (27 males, 42.0±14.1 years) diabetic patients at onset of diabetes. Children with age at onset under 4 years and adults over 55 years were excluded to eliminate the aging effect and the influence of obstructive arteriosclerosis. Neuropathy was defined as abnormal nerve conduction findings in two or more nerves including the sural nerve. Results: Mean HbA1c level was 12.6±3.3% for type 1 and 10.5±2.9% for type 2 diabetes. The prevalence of neuropathy was 12.2% for type 1, and 35.0% for type 2 diabetes, respectively. There were significant trends in the prevalence of neuropathy with increasing age (p<0.05). The effect of the mean level of glycosylated hemoglobin on the prevalence of polyneuropathy at onset of diabetes was borderline (p=0.0532). Neither sex of the patients nor the type of diabetes affected the neurophysiologic abnormalities at the diagnosis. Conclusions: Even in a population with diabetes at the diagnosis, the prevalence of subclinical neuropathy was not low. Neuropathy has been significantly associated with increasing age indicating the possibility of longer duration of undetected diabetes among them, especially in type 2 diabetes.

Background
s and Objectives : In the length-dependent axonal polyneuropathy like diabetic polyneuropathy (DPN), the distal part of the longer axons are affected earlier. In cases of minimal distal axonal changes, nerve conduction studies (NCS) are frequently normal. If sural nerve is affected in the early stage of DPN, supportive parameters to detect the early axonal degeneration may be helpful. We investigated whether the sural/lunar SNAP amplitude ratio (SUAR) may be a more sensitive indicator than sural amplitude alone in the diagnosis of early diabetic polyneuropathy. Methods: We analyzed medical records and electrophysiological studies of 141 patients with DM and 30 healthy subject. The patients with early stage of DPN were defined as those having symptoms of neuropathy and normal NCS findings among the patients with DM. We compared SUAR between 57 patients with early stage of DPN and 71 age-matched control subjects. Results: Fifty seven patients had an average SUAR of 0.8, compared to that of 1,1 in the 71 normal controls. The SUAR of less than 0.9 was supplementary predictor of axonal polynerupathy, with the best balance of sensitivity and specificity (70%). The SUAR did not vary significantly with age, height or duration of DM. Conclusions: We conclude that the SUAR is a useful electrodiagnostic indicator to detect early stage of DPN.

Diabetic polyneuropathy (DPN) is the most frequently encountered form of neuropathy in diabetic patients, and it either relentlessly progresses or remains relatively stable for many years, not showing any trend towards improvement. From this point of view, early detection of DPN is very important to prevent the irreversible change of the peripheral nerve from diabetic insults. Although a number of clinical symptoms and/or deficit scales have been developed for clinical or research purposes, nerve conduction study (NCS) has been known one of the most objective and sensitive tools to detect peripheral nerve dysfunctions in diabetic patients. NCS, however, also have several shortcomings. The next two consecutive articles will focus on debates about diagnostic usefulness of NCS and on recent updates of other diagnostic tests including quantitative sensory testings and skin biopsy in the field of diabetic polyneuropathy.

Background
Although quantitative sensory test (QST) is being used with increasing frequency for measuring sensorythresholds in clinical practice and epidemiologic studies, there has been no age-matched normative data in Korean adults.The objective of this study is to evaluate the value of QST in diabetic polyneuropathy with normal range in Korean adults.Methods: The Computer Aided Sensory Examination IV 4,2 (WR Medical Electronics Co., Stillwater, Minnesota, U.S.A.),with 4,2,1 stepping algorithm was used to determine vibration and cold perception threshold in 70 normal controls and 19patients with diabetic polyneuropathy aged from 21 to 79 years. The data were used to define age-matched upper and lowernormal limits and normal range of side to side difference. We also evaluated the duration of diabetes, serum HbA1C level,and findings of nerve conduction study (NCS) and QST in patients with diabetic polyneuropathy. Results: In normal adults,sensory thresholds slightly increased with age, and a slight side-to-side difference was observed. The diagnostic sensitivityof QST was not higher than NCS in patients with diabetic polyneuropathy (36.8% vs. 42.1%, p=0.716), especially amongelderly patients. Conclusions: QST might be used as a complementary test for NCS in the diagnosis of diabeticpolyneuropathy. Although the QST is a simple method for the evaluation of peripheral nerve function, there are somelimitations. Most of all, because the QST measuring is dependent on the subjective response of patients, the degree of concentrationand cooperation of the patients can significantly affect the result. And thus, attention should be paid during theinterpretation of QST results in patients with peripheral neuropathy.