Evidence for central nervous system demyelination in chronic inflammatory demyelinating polyradiculoneuropathy

It is unclear whether sporadic reports of concurrent multiple sclerosis (MS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) represent coincidence or whether these two demyelinating disorders are pathogenically related. We utilized the sensitivity of magnetic resonance imaging (MRI) in detecting central nervous system (CNS) lesions to investigate 16 patients with CIDP. Six of the 16 had periventricular, subcortical, and brainstem white matter lesions indistinguishable from those seen in MS. Three of these patients had definite clinical and laboratory evidence of MS; three others with abnormal MRIs had no findings indicative of CNS disease. Previous reports have indicated that a significant number of MS patients have peripheral nerve demyelination. Our study suggests that many CIDP patients have concurrent CNS demyelination. Taken together, these observations support the existence of a central-peripheral inflammatory demyelinating syndrome. Whether this combined demyelinating syndrome lies on a spectrum between MS and CIDP or is a separate pathogenic entity will require further investigation.