Background: Chronic inflammatory demyelinating polyneuropathy (CIDP) seems to be more common in diabetic patients than in general population. The long term outcome of these patients after receiving intravenous immunoglobulin is unclear and the precise optimal regimen needed is yet to be ascertained. Moreover it is not clear the influence of chronic hyperglycemia on this neuropathy.
Methods: Consecutive diabetic patients with clinical polyneuropathy referred to our neuromuscular disease unit during the 18 months of the study were exhaustively examined and prospectively followed-up.
Results: One hundred and ninety eight consecutive patients were referred to our neuromuscular unit and exhaustively screened. Sixteen diabetic patients (8%) had a demyelinating polyneuropathy fulfilling the most restrictive diagnostic criteria for CIDP. They were treated with at least one course of intravenous immunoglobulin and, if responders, retreated in case of relapse. All patients were followed for at least 40 months. Diabetic patients with chronic inflammatory demyelinating polyneuropathy significantly improved after immunotherapy and during the follow up. The NIS score changed from 38 at presentation to 16 at the end of the follow-up. Eight patients developed distal sensory disturbances during the follow-up and 4 of these patients complained of distal paresthesias but no neuropathic pain. Sensory disturbances were detected after 30 months (mean time) from baseline.
Conclusions: Chronic inflammatory demyelinating polyneuropathy is not an unusual neuropathy in diabetic patients. Our study underlines the importance of extensively investigating diabetic patients with polyneuropathy to identify patients with a treatment-responsive demyelinating polyneuropathy.