Effect of hyperglycemia on conduction parameters of tibial nerve's fibers to different muscles: A rat model

INTRODUCTION: Routine conduction studies reflect the summation of all nerve fibers in a peripheral nerve. Nerve fiber groups to distal, small muscles have smaller diameters than the ones to large proximal muscles. There may be minimal differences between the diameters of nerve fiber groups innervating different muscles; even they are all same type of fibers. So, in neuropathic processes some nerve fiber groups may be more seriously affected. MATERIALS AND METHODS: 14 rats ( 7 diabetic, 7 control) were studied. Tibial nerve was stimulated from two points and while recorded from a distal (foot intrinsic muscles) and a proximal (gastrocnemius) muscle. RESULTS: There was a significant difference between the proximal and distal recorded conduction velocities. Both proximal and distal recorded conduction velocities decreased during the hyperglycemic process. DISCUSSION: Our method successfully demonstrated different nerve fiber groups; but, the neuropathic process seemed to be homogeneous in both fiber groups.