The purpose of this study was to determine whether an aldose reductase inhibitor (ARI, ONO-2235) or prostaglandin E1 (PGE1) could prevent or improve the impairment of nerve conduction in diabetic patients. Two groups of patients with diabetic neuropathy were the subjects of the study. The first group was treated with ARI and the second group with PGE1. The treatment lasted for six weeks in both groups. Conduction velocities of the median, posterior tibial and/or ulnar nerve were measured before and after the treatment in each patient.
Before ARI treatment, reduction of the motor nerve conduction velocity (MCV) of the median nerve was observed in one of three patents, and that of the sensory nerve conduction velocity (SCV) of the median nerve in all three. Four out of six patients had reduction of the MCV in the ulnar nerve and four out of seven in the posterior tibial nerve. After the treatment, slight improvements of the conduction velocities were observed in six of 12 (50%) measurements in the above nerves with decreased conduction velocities. But no significant alteration in the mean values of nerve conduction velocities between before and after the treatment was observed.
Before the PGE
1 treatment, impairment of the MCV of the median nerve was observed in four of five patients, reduction of the mixed nerve conduction velocity (MNCV) of the median nerve in all five and reduction of the SCV of the median nerve in three of five. Two out of six patients showed reduction of the MCV in the postrior tibial nerve. After the PGE1 treatment, a slight improvement was observed in five of 14 (36%) measurements in the peripheral nerves with impaired conduction velocities. But there were no significant changes in the mean values of the nerve conduction velocities before and after PGE1 treatment.
It is concluded that ARI or PGE1 treatment results in some improvement the peripheral nerve function in diabetic neuropathy and that there is a limitation on the efficacy of these treatments in advanced neuropathic states.
