Background: Diabetic neuropathy is recognised as the most common clinical picture of nervous system disorders caused by DM and is considered the most common type of neuropathies.
Objective and hypotheses: To evaluate the relationship between the sonographically measured cross-sectional area (CSA) of the median nerve and nerve conduction study (NCS) in children with type1 diabetes (T1DM) complaining of DPN.
Method: 40 children withT1DMand 20 age-matched healthy subjects were enrolled in this study. The diabetic children were divided into two groups (without and with DPN). All participants underwent NCS and sonographic measurement of CSA for the median nerve in the carpal tunnel. All NCS were done on both median nerves measuring the motor nerve conduction velocity (MNCV) and the motor latency from the elbow to the wrist joint.
Results: Patients with T1DM (mean age 15.2±2.9 years, duration 8.4±4.1 years, all participants were on intensive insulin therapy in a dose ranging from 0.5 to 2.5 IU/kg per day with a mean of 0.41.8 IU/kg per day. The CSA of the median nerve in children with DPN was higher than that in the control subjects yet with no significant difference with that of children without DPN. The mean value of median nerve motor latency was diminished in patients with DPN in comparison to patients without DPN and controls (3.5, 3.4, 2.96 ms respectively, P=0.005). The mean value of median nerve MNCV in the control individuals showed no significant difference (P=0.085) compared to that of children without DPN and statistically significant difference (P=0.016) compared to that of children with DPN as it was 54.6 m/s vs 52.9 m/s and 54.6 m/s vs 51.5 m/s respectively. The increased median nerve CSA in the carpal tunnel was considerably correlated with the median nerve motor latency and duration of diabetes, nevertheless, with no correlation with median nerve motor conduction velocity (MNCV). The best cut-off value of the sonographically measured median nerve CSA for discrimination between control individuals and children with DPN is (0.046) with sensitivity=100%, specificity=80%, PPV=83.3%, NPV=100%.
Conclusion: Our data implicate that sonographic measurement of CSA is a good alternative to NCS results of motor latency and MNCV for the diagnosis and follow up of diabetic neuropathy. Moreover, the duration of disease and impaired glycaemic control play an important role in the development of peripheral neuropathy. Sonographic measurement of CSA of the median nerve in the carpal tunnel serves as a good discriminator for diabetic children from healthy individuals. Moreover, it has significant positive correlation with duration of disease and the nerve motor latency.
01 - 03 Oct 2015
European Society for Paediatric Endocrinology