P 26 Evaluation of clinical, electrophysiological, sonographic and MRI characteristics of the CIDP spectrum disorder

Abstract

Introduction Chronic inflammatory demyelinating polyneuropathy (CIDP) is an autoimmune disease with a wide spectrum of clinical presentation and treatment response. Electrophysiological studies constitute the gold standard used to characterise CIDP patients and contribute to treatment decisions. However, mostly at late stages electrophysiological methods show a pronounced axonal damage and are not able to distinguish CIDP subtypes. Therefore, therapeutic decisions have to be based solely on the clinical course. We investigated the applicability of nerve ultrasound and magnetic resonance imaging (MRI) in a cohort of CIDP patients at a late stage with a variable clinical presentation and correlated our findings to electrophysiological parameters. Methods We systematically examined the median, ulnar, radial, tibial, fibular and sural nerves as well the brachial plexus with high resolution ultrasound (US) and the lumbar roots and tibial, fibular, median, ulnar and radial nerve of eighteen CIDP patients with high-resolution 3 Tesla MRI (including 18 healthy controls) additionally to the nerve conduction studies. Results The mean cross sectional area (CSA) measured in MRI and US of the CIDP patients was increased compared to the healthy controls. A symmetrical clinical presentation correlated with a symmetrical increase of the CSA of the lumbar and cervical plexus. CSA in MRI correlated with the conduction velocity and amplitude. An increase of T2 signal and CSA of the plexus and peripheral nerves which correlated with a marked increase of the sonographical CSA corresponded to patients with an aggressive disease course, which were candidates fon an escalation treatment. Conclusions Nerve ultrasound and MRI findings at late CIDP stages can contribute to the therapeutic decisions and unmask aggressive CIDP patients. Both of them in combination are required to give a complete picture of peripheral nerve alterations in CIDP.