Case Report: Narcolepsy associated with anti-Ma2 antibody positivity

Background Several intraneuronal antibodies have been identified in association with paraneoplastic encephalitis, including anti-Ma and anti-Yo antibodies. There is a pure case of narcolepsy associated with anti-Ma2 antibody positivity with concomitant anti-Yo antibody. Case presentation We report a 42-year-old male patient who presented with recurrent cataplexy as the primary and dominant symptom without typical hyperphagia in the early stages of narcolepsy associated with anti-Ma2 antibody positivity. Despite extensive screening, no underlying malignancy was detected over a 3-year disease duration. The patient exhibited significant clinical improvement following immunotherapy at the beginning. Conclusions This is a rare report of an isolated clinical manifestation of narcolepsy associated with anti-Ma2 antibody positivity with concomitant anti-Yo antibody. This case reminds clinicians to notice that cataplexy could be the only early symptom of narcolepsy associated with anti-Ma2 antibody positivity with concomitant anti-Yo antibody, which can easily lead to misdiagnoses. Autoimmune mechanisms may play an important role in the pathogenesis of narcolepsy associated with anti-Ma2 antibody positivity, and prompt immunotherapy offers a promising approach for its management.