Objective: The objective of this study was to evaluate the effect of intravenous immunoglobulin (IVIg) therapy in diabetic lumbosacral radiculoplexus neuropathy (DLRPN) patients who did not respond to analgesic drug therapy and corticosteroids. Background. DLRPN is a rare painful condition that may occur in diabetes mellitus (DM). At the moment, there are limited therapeutic options for DLRPN.
Methods: We recruited five patients affected by type 2 DM and DLRPN. They were selected from a cohort of 13 consecutive DLRPN patients. Inclusion criteria were severe pain (visual analog scale [VAS] > 4/10) and no response to pain symptomatic therapy and corticosteroids. Patients were treated with IVIg (0.4 g/kg/day for 5 days). Outcome measures were VAS, time of onset and duration of pain relief, the Medical Research Council (MRC) scale for lower limb muscle strength, and walking distance. Electrophysiology and needle electromyography (EMG) were retested after IVIg.
Results: Four of the patients had positive pain response after IVIg. VAS reduction started 5-10 days after IVIg infusion. Two patients underwent additional IVIg infusions due to pain reappearance after 7-18 months, again with positive response. VAS, MRC scale, and walking distance significantly improved at 1 month (Wilcoxon nonparametric test, two-tailed, P < 0.05). Electrodiagnostic testing was unchanged, but needle EMG showed reduction of denervation signs after IVIg.
Conclusions: IVIg may rapidly reduce pain and improve motor function in DLRPN despite previous negative response to corticosteroids. IVIg may be repeated in those patients who experience disease relapse. Future double-blind trials are needed to evaluate the role of IVIg in DLRPN.