Endocrine Abstracts

Background: Diabetes mellitus (DM) causes damage to many organs and systems. The consequences of diabetes mellitus in the central nervous system are less known than diabetic peripheral neuropathy and autonomic nervous system neuropathy. Damage to the brain and the spinal cord is less common.

Aim: The aim of study is to show the importance of motor and somatosensory evoked potentials (MEP and SEP) for early diagnosis of unapparent central nervous system (CNS) damage related to diabetes mellitus.

Methodology: Thirty diabetic patients (type 1 and type 2) and twenty healthy volunteers who match patient group for age and sex, with no clinical symptoms or signs of central or peripheral nervous system lesion were evaluated. MEPs were recorded from upper and lower extremities bilaterally and central conduction time (CMCT) was calculated according to formula: CMCT=MEP−(0.5x (F−M−1)+M). Similarly, spinal and cortical SEP after median nerve stimulation in diabetics and control group were examined. The latencies of individual wave deflections and peripheral (PCT) and CCT of spinal and cortical SEP were measured.

Results: The examination of MEPs and SEPs proved and confirmed the prolongation not only of peripheral conduction time, but also of the central conduction time especially in the lower limbs. There was no correlation between CMCT delay and the degree of metabolic control, type of diabetes (type 1 or type 2 diabetes mellitus), age, disease duration, presence or absence of retinopathy or nephropathy.

Conclusion: In spite of missing clinical signs of CNS lesion in diabetic patients, a significant prolongation of CCT compared to control group was recorded. We suggest a presence of diffuse subclincal CNS lesion induced by many factors. Measurement of CCT using transcranial magnetic stimulation and somatosensory evoked potentials could be a complementary electrophysiological method for assessment of subclincal cerebral and spinal cord involvement in diabetic patient.