The purpose of this work is to better characterize combined central and peripheral demyelination (CCPD) and try to develop new diagnostic criteria using high resolution ultrasound and electroneuromyography. The aim is to allow better discrimination between CIDP, MS and CCPD, establish a nerve ultrasound specific pattern for patients suffering from CCPD and MS, evaluate the proportion of MS patients showing PNS involvement and improve our understanding of the CCPD physiopathological mechanisms.

Nerve ultrasound revealed abnormalities compatible with inflammatory neuropathy in 92.3% of CIDP patients and 100% of CCPD patients. Unexpectedly, 30% of MS patients showed ultrasound abnormalities without clinical symptoms. Nerve ultrasound has also been shown to be more effective than MRI in detecting plexus enlargement.  Finally, the search for specific oligoclonal bands of the CSF was positive in all MS patients while it was negative in all CCPD patients.

Nerve ultrasound is a non-invasive, accessible, inexpensive, side-effect free diagnostic tool which allows easy detection of CIDP and CCPD. Our results show a very similar ultrasound pattern between CIDP and CCPD patients suggesting a common pathophysiological mechanism. The significant number of MS patients showing ultrasound abnormalities raise the question of a possible continuum between the three entities.