Validity of the clinical neurological state and nerve conduction velocity in diagnosing diabetic peripheral neuropathy

Aims: Diabetic peripheral neuropathy (DPN) is a common complication of diabetes with a very slow but progressive course. We aimed to evaluate the prevalence of diabetic peripheral neuropathy in children and adolescents with type 1 diabetes mellitus (T1DM) and examine whether the clinical neurological state validly diagnoses DPN as compared to the gold standard of nerve conduction velocity (NCV) in these patients. Methods: We measured motor and sensory NCV of the median, peroneal and tibial nerve in an unselected consecutive series of 39 patients aged 8–18 years who had been suffering from T1DM for at least one year. NCV values were compared to the results of 18 healthy probands between the ages of 18 to 30 years. The clinical neurological state of the patients was examined using a protocol including ankle reflex, vibration, pin-prick, and temperature testing as well as a standardized questionnaire; neuropathy disability scores (NDS) and neuropathy symptom scores (NSS) were assessed. Results: Of our 39 patients, six (15%) had clinically evident DPN, whereas NCV testing revealed DPN in 15 (38%) patients. In the control group, all NCV values were normal. Sensitivity and specificity of the clinical neurological exam for the diagnosis of DPN as compared to NCV were 40% and 100%, respectively. The corresponding positive and negative predictive values were 100% and 72.7%, respectively. Conclusion: In children and adolescents with T1DM DPN is highly prevalent, but in the majority of patients it is subclinical. Sensitivity and negative predictive values of the clinical neurological exam are low. Therefore, routine NCV measurement for the assessment of DPN appears warranted in these patients diabetic neuropathy - nerve conduction velocity