Introduction: There are some occlusive disorders in the vasa nervorum and metabolic changes disminishing oxygen liberation by erytrocites at the capillary blood vessels, and these disturbances lead to endoneural microhypoxia. Hyperbaric oxygen reverts hypoxia in the diabetic neuropathy.
Objective: We studied motor and sensitive peripheric neuroconduction in nine diabetic patients, with distal symmetrical polyneuropathy, during normoglycemia. Four of them were insulin dependent and five were non insulin dependent.
Patients and methods: The electrophysiological studies were done before treatment with hyperbaric oxygen, in a week, three and six months later. The abnormal electrophysiological parameters detected in diabetics were terminal latencies (enlarged), velocities of conduction (slowed) and distal amplitudes of compound action potentials (reduced).
Results: Neither distal latencies nor distal amplitudes and conduction velocities in peroneal nerve showed significative changes in the statistical analysis. We observed slower conduction velocities in the motor fibers of the median nerve in the examination performed six months after treatment. There was an increase of distal latency and retardation of the velocity of conduction six months later after treatment in the sensitive fibers of median nerve, whereas the amplitudes of sensitive action potentials decreased progressively. These changes suggest large diameter peripheral fibers didn't receive benefit with hyperbaric oxygen treatment.
Conclusions: In all patients disappeared all symptoms of dysesthesias, paresthesias, distal pains and cramps in the legs and arms, suggesting functional changes in small unmyelinated fibers which we can't test with conventional techniques to prove it.