Background: Diagnostic criteria for chronic inflammatory demyelinating polyneuropathy (CIDP) have variable sensitivity and specificity. Newly published criteria by Koski et al.  combine clinical and electrophysiological components, either of which suffices to establish the diagnosis. European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) criteria , require mandatory electrophysiology, as do other sets of criteria.
Methods: We assessed the value of the two above-mentioned sets of criteria, on 151 patients with CIDP, and 162 controls with axonal neuropathy, from four European centres. Results were compared with Van den Bergh and Piéret’s criteria , and those of the American Academy of Neurology (AAN) . The utility of more extensive nerve conduction studies was ascertained.
Results: Koski et al.’s criteria had a sensitivity of 63 % and specificity of 99.3 %. With unilateral, right-sided, forearm/foreleg, four-nerve studies, EFNS/PNS criteria offered a sensitivity of 81.3% and specificity of 96.2% for “definite/probable” CIDP. Van den Bergh and Piéret’s criteria had a sensitivity of 79.5% and specificity of 96.9%. AAN criteria were poorly sensitive (45.7%) but highly specific (100%). “Possible” electrophysiological CIDP as per EFNS/PNS criteria were poorly specific (69.2%). More extensive studies increased diagnostic sensitivity of EFNS/PNS criteria (96.7%) but reduced specificity (79.3%).
Conclusions: In our patient populations, the EFNS/PNS criteria were the most sensitive and allowed identifying a highly significantly greater number of patients than Koski et al.’s criteria. The latter were comparable in specificity to the “definite/probable” EFNS/PNS electrodiagnostic subcategories. More extensive nerve conduction studies improved diagnostic yield but resulted in loss of specificity.