P72-S Recurrent proximal motor conduction blocks in a patient with relapsing-remitting predominantly motor form of CIDP

Background Chronic inflammatory demyelinating polyneuropathy (CIDP) is a clinically heterogeneous autoimmune disease. Motor-dominant form of CIDP is frequently presented as relapsing-remitting course. Although motor conduction blocks have to be the pathophysiological substrate in these cases, there is no many descriptions in literature. Material and Methods We report a male patient (63 years old) with relapsing-remitting-CIDP, with 4 episodes of acute motor weakness that responded well to endovenous inmunoglobulin treatment. Results Electrophysiological studies showed diffuse demyelinating changes in motor conduction studies in upper and lower limbs, and minor sensory conduction abnormalities. Relapsing-remitting motor conduction blocks were demonstrated in proximal segments of upper limb nerves, in parallel with improvement and worsening clinical changes. Conclusions Recurrent proximal motor conduction blocks are demonstrated in a patient with relapsing-remitting predominantly motor form of CIDP. Differential diagnosis and the pathophysiological basis is discussed.