Reliability of Presynaptic Inhibition in Patients with Diabetic Peripheral Neuropathy

There has been rising interest in evaluating spinal reflex activity within the clinical population, however no study has yet investigated the reliability of presynaptic inhibition (PI) on patients with diabetic peripheral neuropathy (DPN). Because neuropathy is closely related to central nervous system modification, it is important to understand the mechanism of spinal reflex activity in the DPN population. Therefore, the purpose of the study was to evaluate the reliability of PI in patients with DPN. Eight participants (58.24 +/- 6.38 yrs.) diagnosed with either type I or type II diabetes and peripheral neuropathy were recruited for the study. Each subject's H-reflex was measured using an EMG to elicit and record a series of 10 paired reflex depression trials. Reliability was measured by calculating Intra Class Correlation Coefficients (ICCs) with a 95% confidence interval. The results showed excellent reliability in both intraday (0.94) and interday (0.88) reliability. Therefore, analyzing PI in the central nervous system allows for an accurate evaluation of spinal cord circuitry in a non-invasive manner.