Therapeutic Advances in Neurological Disorders (Aug 2023)

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

  • Louisa Müller-Miny,
  • Raoul Sauer,
  • Andreas Schulte-Mecklenbeck,
  • Catharina C. Gross,
  • Stjepana Kovac,
  • Matthias Schilling,
  • Carolin Beuker,
  • Heinz Wiendl,
  • Gerd Meyer zu Hörste

DOI
https://doi.org/10.1177/17562864231189323
Journal volume & issue
Vol. 16

Abstract

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