Spinal cord lesions in diabetes mellitus. Somatosensory and motor evoked potentials and spinal conduction time in diabetes mellitus.

OBJECTIVES: Diabetic neuropathy and autonomic nervous system neuropathy are recognized as the most common clinical pictures of nervous system disorders caused by diabetes mellitus (DM). Damage to the brain and the spinal cord is rare. The aim of this work is to show the importance of somatosensory and motor evoked potentials (SEP and MEP) for the early diagnosis of nervous system damage related to diabetes mellitus.

MATERIAL AND METHODS: We examined spinal and cortical somatosensory evoked potentials (SEP) after median and fibular nerve stimulation in diabetics and control subjects. We measured the latencies of individual wave deflections and peripheral and central conduction time (PCT and CCT) of spinal and cortical SEP. Similarly, transcranial magnetic stimulation was used for measuring the central and peripheral conduction time (CCT and PCT) in a group of type 1 diabetics and a control group of volunteers.

RESULTS: The examination SEP and MEP proved and confirmed the prolongation not only of peripheral conduction time, but also of the central conduction time - especially in spinal cord structures. An assumption that spinal cord changes are connected with the decreased number of myelinated fibers able to conduct the impulses from periphery and brain cortex, respectively, has to be accepted.

CONCLUSIONS: The results suggest that the use of somatosensory and motor evoked potentials (SEP and MEP) examination and conduction times measurement has significance in the confirmation of unapparent lesions of the spinal cord in diabetics of both types.