Abstract
We conducted multicenter trials to assess the reproducibility of nerve conduction studies for use in future drug development for treatment of diabetic polyneuropathy (DPN).
All measurements were repeated twice at intervals of 1 to 4 weeks in 132 healthy subjects (63 men) and 172 patients (99 men) with DPN.Using a standardized method, 32 centers participated in the control study, and 65 in the DPN study.Motor nerve conduction studies consisted of stimulating the left median and tibial nerves and measuring amplitude, terminal latency (TL), and minimal F-wave latency (FWL).For sensory nerve assessment, amplitude was recorded antidromically after distal stimulation of the left median and sural nerves.We also calculated motor conduction velocity (MCV), F-wave conduction velocity (FCV) and sensory conduction velocity (SCV).
The range of relative inter-trial variation (RRIV) and intraclass correlation coefficient (ICC) were used as an index of reproducibility.Of all the measurements, FWL yielded the highest ICC with the smallest RRIV for both median and tibial nerves in healthy subjects as well as in DPN.We conclude that median and tibial FWL provide the most reproducible measure ments for sequential nerve conduction studies in multicenter trials of diabetic polyneuropathies.
