There is a knowledge gap with regards to the appropriate method of detecting and treating chronic inflammatory demyelinating polyneuropathy (CIDP), in patients with co-existent diabetes. In this pilot study the investigators plan to examine the overlap between diabetic polyneuropathy and CIDP by treating patients with diabetes and demyelinating abnormalities using IVIg. The investigators will enroll diabetes patients with a broad spectrum of demyelinating abnormalities.~The proposed trial will be an explanatory, blinded, single-centre, superiority, randomized controlled cross-over trial. Each patient will receive 3 months of 10% intravenous immunoglobulin and 3 months of placebo (0.9% sodium chloride in water) with a 3-month washout period. The primary outcome measure is the mean change in ONLS (Overall Neuropathy Limitation Scale), a measure of disability in polyneuropathy; however secondary outcome measures will consider impairments and quality of life.
The purpose of this study is to determine whether intravenous immunoglobulin (IVIg) is an effective intervention for patients with diabetes, peripheral neuropathy, and demyelination on nerve conduction studies. All patients will receive both IVIg and placebo for 3 months each, with a 3 month washout period in between.