Contactin-associated protein 2 autoantibodies can be associated with multifocal motor-like neuropathy: a case report

Autoantibodies against contactin-associated protein 2 (CASPR2) are usually associated with autoimmune encephalitis and neuromyotonia. Their association inflammatory neuropathies has been described in case reports albeit all distal symmetric manifestation. Here, we report a patient who developed arm paresis, dominantly of the right arm, over course 1 year. Electroneurography showed conduction block motor nerve conduction, ultrasonography swelling median ulnar flow cytometry an increase natural killer (NK cells) blood T (NKT) cells cerebrospinal fluid (CSF), therefore indicating multifocal neuropathy-like (MMN-like) phenotype. CASPR2 autoantibodies were detected serum CSF. Through immunotherapy intravenous immunoglobulins clinical neurographic improvement. We describe first MMN-like manifestation, extending spectrum CASPR2-associated diseases.