Objective: To investigate whether the asymptomatic involvement of the central and peripheral nervous systems may be an early complication of diabetes.
Research design and methods: We studied early impairment of the central and peripheral nervous system pathways in 15 type I diabetic patients with good metabolic control and short disease duration and in 10 healthy control subjects using a set of neurophysiological tests.
Results: Results in diabetic subjects showed 1) impairment of motor (7% and somatosensory (13%) pathways of the central nervous system, 2) impairment of motor and sensory conduction velocities (40-60%), and 3) normal values of the vibration perception threshold and cardiovascular autonomic tests.
Conclusions: The damage is more evident in peripheral sites where hyperglycemia and aldose reductase pathways are more active. Instead, several episodes of hypoglycemia, which occur in type I diabetic patients in good metabolic control, may cause alterations of brain nervous cells.